BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Hot and thick discs: stability of Initial Conditions and prelimina ry results DTSTART;VALUE=DATE-TIME:20200512T100000Z DTEND;VALUE=DATE-TIME:20200512T102000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-51@meetings.aip.de DESCRIPTION:Speakers: Marco Cilibrasi (University of Zurich)\nBoth the Cor e Accretion and the Gravitational Instability models for giant planet form ation predict the presence of circumplanetary discs (CPDs) during the last formation phases (Alibert et al. 2005\, Ward & Canup 2010). These discs a re found to be continuously fed by an influx of gas from the protoplanetar y disc (Tanigawa et al. 2012). Magnetic fields generated by the disc itsel f could play a key role in modeling this accretion flow (Gressel et al. 20 13). In the early stages of a giant planet's life\, the magnetic field gen erated by the planet could be even stronger\, thus potentially important d epending on how it couples with the surrounding flow (Yadav et al. 2017 an d Cauley et al. 2019)\, and possibly dominant.\nIn the Core Accretion scen ario\, CPDs are expected to be very hot and thick when forming. For such d iscs\, regardless of their nature (CPD or PPD)\, standard thin-disc approx imations can not be used to set ICs and new numerical and analytical metho ds have to be investigated\, to ensure especially equilibrium at boundarie s. Here we present a study of equilibrium initial conditions for thick and hot disc simulations with the meshless finite mass (MFM) method in the GI ZMO code (Hopkins 2015\; Deng et al.2019)\, which can be used by any code utilizing a particle-based representation of the fluid. \nTime permitting \, we will show preliminary results obtained after setting a CPD initial c ondition with these methods and adding magnetic fields to our simulation.\ n\nhttps://meetings.aip.de/event/1/contributions/51/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/51/ END:VEVENT BEGIN:VEVENT SUMMARY:Dust dynamics in self-gravitating disks – could planet formation start in young disks? DTSTART;VALUE=DATE-TIME:20200514T144500Z DTEND;VALUE=DATE-TIME:20200514T150500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-70@meetings.aip.de DESCRIPTION:Speakers: George Mamatsashvili (Helmholtz-Zentrum Dresden-Ross endorf)\nI will present the results on the evolution of dust particles in self-gravitating disks residing in a gravitoturbulent state\, when heating due to shocks of density waves balances cooling. It is well known that d ensity structures in the gaseous component of the disk induced by self-gra vity (gravitational instability) can trap dust efficiently enough\, so tha t the dust component itself undergoes further gravitational collapse due t o its own self-gravity. Previous results both in global and local shearing box studies indicate that over-pressure regions related to spiral density waves can be very efficient at collecting dust particles\, creating signi ficant local over-densities of particles. The degree of such concentration s depends on two parameters: the size of dust particles and the rate of ga s cooling. In recent years\, increasing observational evidence indicates t hat large-scale vortices (e.g.\, induced by planetary gaps) and rings are most preferable sites of dust trapping. \n\nMotivated by this\, we studied effects of vortices on the evolution of dust particles using local sheari ng box simulations of self-gravitating protoplanetary disks\, including al so the dust-back reaction on gas and self-gravity of the dust component it self. In contrast to non-self-gravitating disks\, vortices in self-gravita ting disks tend to be smaller-scale (of the order of local Jeans scale) an d short-lived structures. We found that these types of structures are neve rtheless quite efficient at trapping small and intermediate-sized dust par ticles with friction times comparable to\, or less than\, the local orbita l period of the disk. This can lead to significant over-densities in the s olid component of the disk\, with density enhancements comparable to\, and even higher\, than those within spiral density waves\; increasing the rat e of gravitational collapse of dust into bound structures (planetesimals). I will also discuss the resulting surface density structure of dust trapp ed in such vortices in connection with recent observations of disks.\n\nht tps://meetings.aip.de/event/1/contributions/70/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/70/ END:VEVENT BEGIN:VEVENT SUMMARY:A massive planet disruption as the source of dust in TW Hydra prot oplanetary disc DTSTART;VALUE=DATE-TIME:20200513T084500Z DTEND;VALUE=DATE-TIME:20200513T090500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-58@meetings.aip.de DESCRIPTION:Speakers: Sergei Nayakshin (University of Leicester)\nThe prot ostar TW Hydra features the best studied and one of the most unusual proto planetary discs. Its dust disc has a cliff-like rollover at 52 AU which co incides with a suspected sub-Neptune mass planet recently detected as an a zimuthally elongated AU-scale excess in ALMA 1.3 mm continuum (Tsukagoshi +19). Here we build detailed models of dust growth\, dynamics and syntheti c disc emission to investigate the origin of TW Hydra's peculiarities.\n\n \nWe show that the standard scenario in which the dust in TW Hydra disc is primordial accounts neither for the dust morphology nor the excess emissi on. We propose an alternative model in which the primordial dust is long c onsumed by the star or locked in planets\; the dust currently observed in the system is ejected by the suspected ALMA planet. We show that in this m odel the mm-sized dust particles are blown inside the planetary orbit\, na turally explaining the dust disc morphology and its relation to the 1.3 mm excess. Further\, dust lost by the planet performs a characteristic U-tur n relative to the planet producing an azimuthally elongated emission featu re similar to the one observed by ALMA. Finally\, the disruption scenario provides an attractive explanation for why one of the oldest protoplanetar y discs happens to be tens times more massive in terms of dust than most d iscs a fraction of TW Hydra's age.\n\n\nWe consider two scenarios for the nature of the dust-loosing planet. In the first\, a dusty pre-collapse gas envelope of a massive core growing in the Core Accretion framework is dis rupted\, e.g.\, as a result of a catastrophic encounter. In the second\, a massive dusty gas giant planet formed in the Gravitational Instability sc enario is disrupted by the energy release in its massive core. In the latt er case all of TW Hydra protoplanetary disc\, including its gaseous compon ent\, may originate in such a disruption\; the planet mass has to be no la rger than 2 Jupiter masses and it must be 5-10 times more abundant in meta ls than the Sun.\n\nIf these ideas are correct then future observations of TW Hydra\, and potentially other discs\, will allow us to study planet fo rmation in an entirely new way -- by analysing the flows of dust and gas r ecently belonging to giant planets. Reverse engineering of mass loss from the planets may inform us about their density structure and elemental comp osition before the disruption.\n\nhttps://meetings.aip.de/event/1/contribu tions/58/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/58/ END:VEVENT BEGIN:VEVENT SUMMARY:Thursday afternoon discussion DTSTART;VALUE=DATE-TIME:20200514T151000Z DTEND;VALUE=DATE-TIME:20200514T160000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-69@meetings.aip.de DESCRIPTION:https://meetings.aip.de/event/1/contributions/69/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/69/ END:VEVENT BEGIN:VEVENT SUMMARY:Shotgun poster session DTSTART;VALUE=DATE-TIME:20200511T124000Z DTEND;VALUE=DATE-TIME:20200511T130000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-68@meetings.aip.de DESCRIPTION:https://meetings.aip.de/event/1/contributions/68/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/68/ END:VEVENT BEGIN:VEVENT SUMMARY:Tuesday afternoon discussion DTSTART;VALUE=DATE-TIME:20200512T151500Z DTEND;VALUE=DATE-TIME:20200512T154500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-67@meetings.aip.de DESCRIPTION:https://meetings.aip.de/event/1/contributions/67/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/67/ END:VEVENT BEGIN:VEVENT SUMMARY:Monday afternoon discussion DTSTART;VALUE=DATE-TIME:20200511T150000Z DTEND;VALUE=DATE-TIME:20200511T154500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-64@meetings.aip.de DESCRIPTION:https://meetings.aip.de/event/1/contributions/64/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/64/ END:VEVENT BEGIN:VEVENT SUMMARY:Welcome and Introduction DTSTART;VALUE=DATE-TIME:20200511T104500Z DTEND;VALUE=DATE-TIME:20200511T110000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-63@meetings.aip.de DESCRIPTION:https://meetings.aip.de/event/1/contributions/63/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/63/ END:VEVENT BEGIN:VEVENT SUMMARY:Elemental chemistry in the inner regions of protoplanetary discs DTSTART;VALUE=DATE-TIME:20200515T122000Z DTEND;VALUE=DATE-TIME:20200515T124000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-39@meetings.aip.de DESCRIPTION:Speakers: Pooneh Nazari (Leiden University)\nElemental abundan ce ratios in the inner regions of protoplanetary discs are important for s etting the composition of exoplanets\, but are likely not to represent the bulk composition of the star's parental cloud. Abundance differences are expected to be driven by the differential transport of chemical species in solid and gaseous form: elements which are mainly concentrated in species with high melting points may be either over-represented in the inner disc (due to efficient inward radial drift of icy grains) or else under-repres ented (if such grains become trapped in the outer disc).\n\nHere I explore a new observational window for determining the relative abundances of C\, N and Si in the inner disc through examination of ultraviolet emission li nes generated by material accreting onto the central star via an accretion column and shock. I use CLOUDY to calculate the resulting ratios of CIV\, NV and SiIV lines and how these vary with input elemental abundance ratio s. I conclude that such line ratios provide a sensitive probe of abundance s in the inner disc and describe the constraints provided by existing HST spectroscopic observations of T Tauri stars.\n\nhttps://meetings.aip.de/ev ent/1/contributions/39/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/39/ END:VEVENT BEGIN:VEVENT SUMMARY:Locating the water snowline in protoplanetary disks using the chem ical tracer H13CO+ DTSTART;VALUE=DATE-TIME:20200515T115500Z DTEND;VALUE=DATE-TIME:20200515T121500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-62@meetings.aip.de DESCRIPTION:Speakers: Margot Leemker (Leiden University)\nSnowlines\, in p articular the water snowline\, are important for the formation of planets in protoplanetary disks. However\, locating the water snowline directly is challenging. Firstly\, due to the proximity of the water snowline to the host star. But ALMA can now resolve this region for the first time. Second ly\, due to the absorption of water in the Earth's atmosphere. A chemical tracer\, HCO+\, provides a solution to the latter problem. HCO+ is destroy ed by gas-phase water\, therefore no HCO+ is expected to be present when w ater desorps from the grains. It has already been shown by van 't Hoff et al. (2018) that the optically thin isotopologue\, H13CO+\, acts as a trace r of the water snowline in the envelope around a Class 0 object. We invest igate whether this also works in Class 2 objects where planets form. The H CO+ abundance is modeled using our small chemical network and using the de nsity and temperature structure from a DALI model. The expected emission i s modeled for different transitions of H13CO+. I will discuss how well H13 CO+ traces the water snowline in disks. We can already confirm that the HC O+ abundance drops when water desorps from the grains and I will discuss w hat observations are needed to locate the water snowline with ALMA.\n\nhtt ps://meetings.aip.de/event/1/contributions/62/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/62/ END:VEVENT BEGIN:VEVENT SUMMARY:Predicting the Observational Signature of Migrating Neptune-sized Planets in Low-viscosity Disks DTSTART;VALUE=DATE-TIME:20200515T113000Z DTEND;VALUE=DATE-TIME:20200515T115000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-33@meetings.aip.de DESCRIPTION:Speakers: Philipp Weber (Niels Bohr Institute)\nThe migration of planetary cores embedded in a protoplanetary disk is an important mecha nism within planet-formation theory\, relevant for the architecture of pla netary systems. Consequently\, planet migration is actively discussed\, ye t often results of independent theoretical or numerical studies are uncons trained due to the lack of observational diagnostics designed in light of planet migration. In this work we follow the idea of inferring the migrati on behavior of embedded planets by means of the characteristic radial stru ctures that they imprint in the disk’s dust density distribution. We run hydrodynamical multifluid simulations of gas and several dust species in a locally isothermal α-disk in the low-viscosity regime (α = 10-5) and i nvestigate the obtained dust structures. In this framework\, a planet of r oughly Neptune mass can create three (or more) rings in which dust accumul ates. We find that the relative spacing of these rings depends on the plan et’s migration speed and direction. By performing subsequent radiative t ransfer calculations and image synthesis we show that—always under the c ondition of a near-inviscid disk—different migration scenarios are\, in principle\, distinguishable by long-baseline\, state-of-the-art Atacama La rge Millimeter/submillimeter Array observations.\n\nhttps://meetings.aip.d e/event/1/contributions/33/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/33/ END:VEVENT BEGIN:VEVENT SUMMARY:Modelling microphysics in MHD: ambipolar diffusion\, chemistry\, a nd cosmic rays DTSTART;VALUE=DATE-TIME:20200513T142000Z DTEND;VALUE=DATE-TIME:20200513T144000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-57@meetings.aip.de DESCRIPTION:Speakers: Tommaso Grassi (USM/LMU)\nFrom molecular clouds to p rotoplanetary disks\, non-ideal magnetic effects are important in many ast rophysical environments. Indeed\, in star and disk formation processes\, i t has become clear that these effects are critical to the evolution of the system. The efficacy of non-ideal effects are\, however\, determined by t he complex interplay between magnetic fields\, ionising radiation\, cosmic rays\, microphysics\, and chemistry. In order to understand these key mic rophysical parameters\, we present a one-dimensional non-ideal magnetohydr odynamics code and apply it to a model of a time-dependent\, oblique\, mag netic shock wave. By varying the microphysical ingredients of the model\, we find that cosmic rays and dust play a major role\, and that\, despite t he uncertainties\, the inclusion of microphysics is essential to obtain a realistic outcome in magnetic astrophysical simulations.\n\nhttps://meetin gs.aip.de/event/1/contributions/57/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/57/ END:VEVENT BEGIN:VEVENT SUMMARY:Consistent Microphysics in Protoplanetary Disk Simulations DTSTART;VALUE=DATE-TIME:20200513T135500Z DTEND;VALUE=DATE-TIME:20200513T141500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-16@meetings.aip.de DESCRIPTION:Speakers: Lile Wang (Center for Computational Astrophysics\, F latiron Institute)\nConsistent time-dependent modeling of microphysics\, e specially thermochemistry and radiation-matter interactions\, is desired b y the studies on protoplanetary disks. In this talk\, I will introduce our GPU-accelerated numerical infrastructures for consistent microphysics co- evolved with (magneto-)hydrodynamic simulations. Their applications in the studies of protoplanetary disk dispersal processes will be elaborated\, i ncluding photoevaporation and magnetized wind-driven accretion mechanisms. Formation of disk substructures is also explored using our system\, empha sizing the necessity of non-ideal MHD consistently coupled with microphysi cs.\n\nhttps://meetings.aip.de/event/1/contributions/16/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/16/ END:VEVENT BEGIN:VEVENT SUMMARY:A Post-Processing Pipeline for Proto-Planetary Disk Simulations (P PPPPDS) DTSTART;VALUE=DATE-TIME:20200513T133000Z DTEND;VALUE=DATE-TIME:20200513T135000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-13@meetings.aip.de DESCRIPTION:Speakers: Jon Ramsey (Virginia Initiative on Cosmic Origins\, Department of Astronomy\, University of Virginia)\nI will present a new po st-processing pipeline for (magneto-)hydrodynamic simulations of protoplan etary accretion disks and results from its first application. By combining publicly available radiative transfer and astrochemistry tools\, we proce ss snapshots from radiative\, non-ideal MHD simulations of thermally-assis ted centrifugal outflows from disks (Gressel et al. 2020) to search for ob servational signposts of outflows which are accessible from current observ atories. In particular\, we compare synthetic observations from models wit h and without outflows to determine which transitions and chemical species can be used to distinguish between the two classes of models. We find tha t the shape of the line profiles\, and velocity asymmetries in moment 1 ma ps\, can discriminate between disks with and without outflows. By combinin g the synthetic observations with the full simulation data\, we can also p inpoint where emission from a particular line or species is coming from in the outflow and/or disk\, which can help us better understand existing an d future observations of disks and outflows.\n\nhttps://meetings.aip.de/ev ent/1/contributions/13/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Measuring dust-gas coupling via the gas rotation curve DTSTART;VALUE=DATE-TIME:20200514T075000Z DTEND;VALUE=DATE-TIME:20200514T081000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-19@meetings.aip.de DESCRIPTION:Speakers: Giovanni Rosotti (Leiden University)\nALMA is showin g that most proto-planetary discs are highly sub-structured and that the m ost frequent structure consists in azimuthally symmetric "gaps and rings". Rings have attracted a lot of attention since they might be the signature of young planets. But rings are extremely important for another reason: t hey provide us with a privileged window inside disc physics. Indeed\, as s hown by the DSHARP team\, their finite dust width shows that there must be some level of dust diffusion\, or else the dust would only collect at the pressure maximum. However\, the DSHARP team was only able to place a lowe r limit\, and not to measure\, the amount of diffusion\, because they did not have information on the gas distribution. I will show how the analysis of the gas rotation curve\, another breakthrough enabled by ALMA observat ions of molecular lines\, is a powerful way to measure the width of rings in the gas and therefore allows us to measure the dust-gas coupling\, whic h controls the dust ring width. Formally\, the relevant parameter is the r atio between the Shakura-Sunyaev α and the dust Stokes number St. I will also discuss the impact of the disc 3D structure on this analysis and show that the measurement of ring width is robust towards the details of the v ertical structure. At the moment\, there are only two objects with good en ough S/N to perform these measurements. In these objects\, I will report g as widths larger than in the dust\, consistently with the idea of dust tra pping. I will show how the data point to a relatively high degree of dust- gas coupling (typical α/St ~ 0.1). Scenarios with very low levels of turb ulence and high levels of grain growth can therefore be rejected. Future c onstraints on the dust grain size in the rings will help in breaking the d egeneracy between St and alpha.\n\nhttps://meetings.aip.de/event/1/contrib utions/19/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/19/ END:VEVENT BEGIN:VEVENT SUMMARY:Doppler flips and wiggles in long baseline observations of protopl anetary disks with ALMA DTSTART;VALUE=DATE-TIME:20200514T072500Z DTEND;VALUE=DATE-TIME:20200514T074500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-55@meetings.aip.de DESCRIPTION:Speakers: Sebastián Pérez (Universidad de Santiago de Chile) \nProtoplanets and circumplanetary disks are elusive yet they are cornerst ones to the most popular interpretations for observed protoplanetary disk structures. The gaseous velocity field also bears the imprint of planet– disk interactions\, with non-Keplerian fine structure in the molecular-lin e channel maps (e.g.\, wiggles or kinks). Such features could in principle be connected to the perturber by comparison with hydrodynamical simulatio ns\, however\, there is a more direct way of pinpointing the protoplanet ’s location: identifying the place where the non-Keplerian velocities un dergo an abrupt sign reversal\, a.k.a. a "Doppler flip"\, in velocity cent roid maps. In this talk\, I will discuss the kinematic signatures of plane t formation and present recent observations of the young disk in HD 100546 in CO emission and dust continuum. The high-resolution 1.3 mm continuum o bservation reveals fine radial and azimuthal substructures in the form of a complex maze of ridges and trenches sculpting a dust ring. Near these du st structures\, we pick up a conspicuous Doppler flip. The 12CO channel ma ps are modulated by wiggles that deviate from Keplerian kinematics and whi ch are somewhat connected to the Doppler flip signal.\n\nhttps://meetings. aip.de/event/1/contributions/55/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/55/ END:VEVENT BEGIN:VEVENT SUMMARY:Measuring 3D Velocities in Planet Forming Disks DTSTART;VALUE=DATE-TIME:20200514T070000Z DTEND;VALUE=DATE-TIME:20200514T072000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-15@meetings.aip.de DESCRIPTION:Speakers: Richard Teague (Center for Astrophysics | Harvard & Smithsonian)\nI will present a novel method to extract azimuthally average d 3D velocity profiles from ALMA data. Application of this to the well stu died source HD 163296 reveals a highly dynamical disk\, hosting large flow structures indicative of meridional flows likely driven by three embedded protoplanets. These flows provide an efficient transport mechanism of vol atile-rich gas in the disk atmosphere towards the planet-forming midplane. In addition\, we find tentative evidence of a slow disk wind in the outer 100 au of the disk\, like connected to the previously detected large scal e wind described in Klaassen et al. (2013). I will further demonstrate how application of this method to multiple molecular species will allow us to map the dynamical structure of a protoplanetary disks in the (r\, z) plan e\, allowing us to directly search for characteristic flow structures whic h will help us to distinguish between potentially active instabilities. I will end with an outlook to how extensions of these methods can be used to search for embedded planets by searching for localized deviations from th e background rotation.\n\nhttps://meetings.aip.de/event/1/contributions/15 / LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/15/ END:VEVENT BEGIN:VEVENT SUMMARY:Winds in transition disks DTSTART;VALUE=DATE-TIME:20200515T093500Z DTEND;VALUE=DATE-TIME:20200515T095500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-61@meetings.aip.de DESCRIPTION:Speakers: Étienne Martel (IPAG)\nProtoplanetary disks (PPD) h ave been widely observed around young stars and are supposed to host plane tary formation. Among these disks stand the transition disks (TD) which ar e characterized by a large hole in the central regions\, whose formation r emains yet unexplained. Despite this hole\, accretion rates comparable to the ones found in PPD are measured\, suggesting an inward motion of matter .\n\nA possible explanation for these high accretion rates is the presence of magnetised winds that would allow matter to fall onto the star at high radial velocity. Following previous works\, the disk can be described usi ng non ideal MHD while the ideal MHD picture is used to compute the wind.\ n\nI will show the impact of the depleted dust repartition in TDs on the i onization fraction through theoretical calculations based on a simple latt ice of chemical reactions. It can be shown that the non ideal MHD effects are also affected by such a hole. I will then present the results of 2D s imulations modelling winds in a TD based on the predicted non ideal effect s profiles.\n\nAxisymetry allows to explore the parameters space and to ch eck the stability of the hole profile through time. Such a work will later on lead the way to a more accurate description of the chemistry at stake in TD and 3D simulations.\n\nhttps://meetings.aip.de/event/1/contributions /61/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/61/ END:VEVENT BEGIN:VEVENT SUMMARY:The time variable dynamics of snow-lines DTSTART;VALUE=DATE-TIME:20200515T091000Z DTEND;VALUE=DATE-TIME:20200515T093000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-31@meetings.aip.de DESCRIPTION:Speakers: James Owen (Imperial College London)\nSnow-lines are regions of protoplanetary discs where volatiles transition from the solid -phase to the gas phase. They play an important role in the chemical evolu tion of protoplanetary discs and perhaps planet/planetesimal formation. Th e majority of work treats these transitions as passive\, uncoupled from th e dynamics. I will argue that snow-lines in the outer regions of protoplan etary discs (where the dis cooling is optically thin)\, are thermally unst able. Namely\, condensation leads to an increase in the solid abundance wh ich leads to increased cooling and more condensation (or vica-versa). I wi ll demonstrate a dynamical simulation that actively couples the condensati on physics\, to the radiative transfer and hence the disc's temperature\, dust dynamics and growth. I will use this simulation to show that snow-lin es are not static\, but dynamically evolve in otherwise stationary discs a nd drive the dynamics in the outer regions of protoplanetary discs. We fin d the CO snow-line can move 10s AU on timescales of a few 1e5 years\, crea ting further structures and rings in the disc and even multiple snow-lines . This thermal instability at snow-lines is likely important for the chemi cal\, thermal and dynamical evolution of protoplanetary discs. It perhaps even plays a role in explaining ringed ALMA discs and planet/planetesimal formation.\n\nhttps://meetings.aip.de/event/1/contributions/31/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/31/ END:VEVENT BEGIN:VEVENT SUMMARY:What are the dynamical signatures of vortices? DTSTART;VALUE=DATE-TIME:20200515T084500Z DTEND;VALUE=DATE-TIME:20200515T090500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-59@meetings.aip.de DESCRIPTION:Speakers: Heloise Meheut (UCA/CNRS)\nThe large scale crescent shape structures detected in protoplanetary disks have sometimes been inte rpreted as vortices. Vortices are of particular interest to understand pla net formation as they are known to concentrate dust and could participate to planetesimal formation. We study the multiple fingerprints of such larg e Rossby vortices and propose observational predictions to test the if the se crescents could be interpreted as vortices.\n\nWe performed 2D hydro-si mulations where a vortex forms at the edge of a gas depleted region. We de rived idealized line-of-sight velocity maps\, varying orientation relative to the observer. The signal of interest\, as a small perturbation to the dominant axisymetric component in velocity\, may be isolated in observatio nal data using a proxy for the dominant quasi-Keplerian velocity. We propo se that the velocity curve on the observational major axis be such a proxy . Applying our method to the disk around HD 142527 as a study case\, we pr edict line-of-sight velocities scarcely detectable by currently available facilities. We show that corresponding spirals patterns can also be detect ed with similar spectral resolutions.\n\nhttps://meetings.aip.de/event/1/c ontributions/59/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/59/ END:VEVENT BEGIN:VEVENT SUMMARY:An Origin of Misaligned Disks and Planetary Orbits: Angular Moment um Accretion in Star Formation Process DTSTART;VALUE=DATE-TIME:20200515T075000Z DTEND;VALUE=DATE-TIME:20200515T081000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-43@meetings.aip.de DESCRIPTION:Speakers: Shu-ichiro Inutsuka (Nagoya University)\nI try to ex plain the primordial origin of misalignment between the disk rotation and host star’s rotation from the context of the disk formation. Theoretical and observational investigations have provided convincing evidence for th e formation of molecular cloud cores by the gravitational fragmentation of filamentary molecular clouds\, which has important implication for the or igin of the stellar initial mass function. On the other hand\, the size an d total angular momentum of a protoplanetary disk are supposed to be direc tly related to the rotational property of the parental molecular cloud cor e where the central protostar and surrounding disk are born. Our recent an alysis concludes that both the mass function and angular momentum distribu tion of molecular cloud core are the natural outcome of transonic turbulen ce with Kolmogorov spectrum in parental filamentary molecular clouds. The implication of this identification is non-homogeneous angular momentum dis tribution inside a molecular cloud core. The actual angular momentum accre tion onto a young stellar object in the core should create misalignment of disk surrounding the star. We show the probability distribution of the mi salignment as a function of disk mass. This finding may explain the origin of misaligned planets created in those disks.\n\nhttps://meetings.aip.de/ event/1/contributions/43/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/43/ END:VEVENT BEGIN:VEVENT SUMMARY:Kinematic signatures of planet-induced warps DTSTART;VALUE=DATE-TIME:20200515T072500Z DTEND;VALUE=DATE-TIME:20200515T074500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-36@meetings.aip.de DESCRIPTION:Speakers: Alison Young (University of Leicester)\nObservations of structures in discs such as gaps and kinks give us a tantalising glimp se of possible planets forming there. Recent numerical simulations show th at planets that are misaligned with respect to the protoplanetary disc may cause the disc to warp and even break into distinct planes. These effects occur even with small misalignments and are therefore likely to be reason ably common. We have performed chemical models of a disc warped by a plane t and used this to predict the kinematic signatures of planet-induced warp s. We highlight the most useful diagnostics\, and discuss how observations can indicate the presence of a planet at various radii within a protoplan etary disc.\n\nhttps://meetings.aip.de/event/1/contributions/36/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/36/ END:VEVENT BEGIN:VEVENT SUMMARY:Ring/gaps formation driven by MHD winds in protoplanetary discs DTSTART;VALUE=DATE-TIME:20200515T070000Z DTEND;VALUE=DATE-TIME:20200515T072000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-23@meetings.aip.de DESCRIPTION:Speakers: Antoine Riols (IPAG Grenoble)\nRings and gaps have b een observed in a wide range of proto-planetary discs\, from young systems like HLTau to older discs like TW Hydra. Recent disc simulations have sho wn that magnetohydrodynamic (MHD) turbulence (in both the ideal or non-ide al regime) can lead to the formation of rings and be an alternative to the embedded planets scenario. In this talk\, I will investigate the way in w hich these ring form in this context and seek a generic formation process\ , taking into account the various dissipative regimes and magnetisations p robed by the past simulations. I will show that a linear instability\, dri ven by MHD winds\, might occur and spontaneously form these rings/gaps str uctures. Given its robustness\, the process identified could have importan t implications for a wide range of accreting systems threaded by large-sca le magnetic fields. To make connection with observations\, I will finally analyze the dust distribution around rings/gaps structures and characteriz e its emission.\n\nhttps://meetings.aip.de/event/1/contributions/23/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/23/ END:VEVENT BEGIN:VEVENT SUMMARY:Synthetic ALMA emission of massive protostellar discs. DTSTART;VALUE=DATE-TIME:20200514T142000Z DTEND;VALUE=DATE-TIME:20200514T144000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-35@meetings.aip.de DESCRIPTION:Speakers: Dominique Meyer (University of Potsdam)\nMassive pro tostellar discs are the sibling circumstellar structures of protoplanetary accretion discs. They form\, evolve as a scaled-up version of the surrou ndings of low-mass stars and both formation mechanisms are unified within the so-called burst mode of star formation. This picture naturally links t he development of gravitational instabilities in centrifugally balanced ac cretion discs to the formation of gaseous clumps and stellar companions wh ich will influence the future evolution of massive protostars in the Hertz sprung–Russell diagram. We perform molecular line emission plus dust con tinuum radiative transfer calculations and compute synthetic images of dis c structures modelled by the gravito-radiation-hydrodynamics simulation of a forming stars\, in order to investigate the Atacama Large Millimeter/su bmillimeter Array (ALMA) observability of circumstellar gaseous clumps and forming multiple systems. We show that substructures are observable regar dless of their viewing geometry or can be inferred in the case of an edge- viewed disc. The observation probability of the clumps increases with the gradually increasing efficiency of gravitational instability at work as th e disc evolves. Our results motivate further observational campaigns devot ed to massive accretion discs as around the protostars S255IR-NIRS3 and NG C 6334I-MM1\, whose recent outbursts are a probable signature of disc frag mentation and accretion variability.\n\nhttps://meetings.aip.de/event/1/co ntributions/35/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/35/ END:VEVENT BEGIN:VEVENT SUMMARY:Global simulations of magnetised self-gravitating protoplanetary d isks DTSTART;VALUE=DATE-TIME:20200514T135500Z DTEND;VALUE=DATE-TIME:20200514T141500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-17@meetings.aip.de DESCRIPTION:Speakers: Lucio Mayer (University of Zurich)\nIn the early st ages of a protoplanetary disk\, when its mass is a significant fraction of its star's\, turbulence generated by gravitational instability (GI) shoul d feature significantly in the disk's evolution. At the same time\, the di sk may be sufficiently ionised for magnetic fields to play some role in th e dynamics.\nThough usually neglected\, the impact of magnetism on the GI may be critical\, with consequences for several processes: the efficiency of accretion\, spiral structure formation\, fragmentation\, and the dynami cs of solids. In this paper\, \nwe report on the first global three-dimens ional magnetohydrodynamical simulations of a self-gravitating protoplaneta ry using the meshless finite mass (MFM)\nLagrangian technique.\nWe confir m that GI spiral waves trigger a dynamo that amplifies\nan initial magneti c field to nearly thermal amplitudes (plasma $\\beta \n\nhttps://meetings. aip.de/event/1/contributions/17/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/17/ END:VEVENT BEGIN:VEVENT SUMMARY:3D global simulations of the Vertical Shear instability DTSTART;VALUE=DATE-TIME:20200514T133000Z DTEND;VALUE=DATE-TIME:20200514T135000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-22@meetings.aip.de DESCRIPTION:Speakers: Marcelo Fernando Barraza Alfaro (Max Planck Institut e for Astronomy\, Heidelberg)\nTurbulence is a key ingredient in the disk evolution and planet formation. However\, the origin of the low level of t urbulence recently observed in protoplanetary disks is not yet well unders tood.\nThe Vertical Shear Instability (VSI) is a candidate to be responsib le for the hydrodynamic turbulence in the outer regions of the disk.\nVia 3D global hydrodynamical simulations\, we study the evolution of the VSI i n an isothermal disk\, with and without an embedded planet. \nWe post-proc ess the outputs of the simulations to study the observability of the VSI. We produce synthetic observations of radiative transfer calculations of th e gas line emission. Further\, we investigate if kinematic signatures of h ydrodynamical turbulence are present in our predictions\, and if they are observable in the near future with ALMA.\nIn this talk\, I will present pr eliminary results on this project.\n\nhttps://meetings.aip.de/event/1/cont ributions/22/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/22/ END:VEVENT BEGIN:VEVENT SUMMARY:Dust Settling Instability in Protoplanetary Disks DTSTART;VALUE=DATE-TIME:20200514T122000Z DTEND;VALUE=DATE-TIME:20200514T124000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-47@meetings.aip.de DESCRIPTION:Speakers: Leonardo Krapp ()\nThe streaming instability has bee n identified as a promising mechanism to concentrate solids and promote pl anetesimal formation in the midplane of disks. It has been demonstrated i n Squire & Hopkins (2018) that a related settling (and streaming) instabil ity (here SSI) occurs as particles sediment towards the midplane. However \, the ability of the SSI to concentrate solids and generate turbulence i s yet to be addressed. To shed light on this aspect\, we present a system atic study of the saturated state of the SSI by performing a series of num erical simulations with the multi-fluid version of the FARGO3D code. We fu rthermore have extended the existing linear analysis to more realistic sce narios including particle size distributions and background disk turbulenc e. Our findings suggest that particle clumping is too weak to trigger pla netesimal formation during the settling of particles\, but the SSI could g enerate weak levels of turbulence in otherwise nearly laminar regimes.\n\n https://meetings.aip.de/event/1/contributions/47/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/47/ END:VEVENT BEGIN:VEVENT SUMMARY:Pebble accretion in turbulent discs DTSTART;VALUE=DATE-TIME:20200514T115500Z DTEND;VALUE=DATE-TIME:20200514T121500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-45@meetings.aip.de DESCRIPTION:Speakers: Giovanni Picogna (Universitäts-Sternwarte München\ , LMU)\nPlanets are born in the mid-plane of accretion discs around young protostars. This process takes place most likely in weakly ionised regions \, where the evolution of the environment is driven by internal turbulence and the gas flow is not laminar but has stochastic components. Turbulence can be generated purely hydrodynamically via different instabilities\, li ke the vertical shear instability (VSI). A fast pathway to the formation o f giant planetary cores has been recently identified in pebble accretion\, though a realistic investigation of this process in a turbulent environme nt was necessary. We tested the solid accretion of a large range of dust s izes on to different planetary core masses in a VSI turbulent global 3D di sc and compared it with a laminar disc. Furthermore\, we tested the influe nce of a realistic equation of state and radiative cooling on the efficien cy of pebble accretion. We found that turbulence decreases slightly the so lid accretion efficiency with respect to analytical calculations of lamina r discs\, having a ~2% efficiency of pebble-like particles for a 5 Earth-m ass planet at 5 au. The introduction of radiative transfer can affect this result significantly by changing the aspect ratio of the disc\, thus the pebble isolation mass.\n\nhttps://meetings.aip.de/event/1/contributions/45 / LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/45/ END:VEVENT BEGIN:VEVENT SUMMARY:The impact of ice mantles on dust evolution in dynamically evolvin g protostellar discs DTSTART;VALUE=DATE-TIME:20200514T113000Z DTEND;VALUE=DATE-TIME:20200514T115000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-26@meetings.aip.de DESCRIPTION:Speakers: Tamara Molyarova (Institute of Astronomy\, Russian A cademy of Sciences)\nThe snowlines of various volatiles are often associat ed with dust evolution in protoplanetary discs and may be identified in ob servations due to their impact on dust properties. In the vicinity of snow lines icy mantles of dust grains sublimate\, which can lead to a different regime of dust growth. Dynamical effects of icy grains crossing snowlines may be reflected in the distribution of volatiles in the gas phase.\nIn t his work\, we present the FEOSAD model of protostellar disc with dust evol ution\, updated to include evolution of icy mantles. The chemical part of the model accounts for time-dependent absorption and desorption of main di sc volatiles (H$_2$O\, CO$_2$\, CH$_4$\, and CO) on two evolving populatio ns of dust grains: small and grown dust. This 2D hydrodynamic code allows to consider the feedback of ice mantles on dust evolution through variable fragmentation velocity. \nWe discuss if the dynamical effects when calcul ating the snowline positions are important for dust growth. We analyse the impact of ice mantles on dust evolution in protostellar discs and discuss the role of ices in the process of planet formation.\n\nhttps://meetings. aip.de/event/1/contributions/26/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/26/ END:VEVENT BEGIN:VEVENT SUMMARY:The role of cosmic rays in protoplanetary disks and young exoplane tary systems DTSTART;VALUE=DATE-TIME:20200514T093500Z DTEND;VALUE=DATE-TIME:20200514T095500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-50@meetings.aip.de DESCRIPTION:Speakers: Donna Rodgers-Lee (Trinity College Dublin)\nThe infl uence of magnetic fields in protoplanetary disk evolution depends sensitiv ely on the level of ionisation present. Protoplanetary disks are thought t o be only very weakly ionised which provides imperfect coupling to magneti c fields and influences disk dynamics. Understanding the sources of ionisa tion\, such as cosmic rays\, present in the disks underpins our overall un derstanding of how these systems evolve and form planets. \n\nHowever\, yo ung solar-type stars are very magnetically active and drive stronger stell ar winds that may shield protoplanetary disks from galactic cosmic rays\, thus losing an important source of ionisation. At the same time\, the incr eased magnetic activity of young stars suggests that protoplanetary disks\ , and young exoplanetary systems\, are bombarded by stellar cosmic rays\, or stellar energetic particles. I will present recent results from our mod el of cosmic ray transport in these systems and the chemical signatures th at we might expect from cosmic rays.\n\nhttps://meetings.aip.de/event/1/co ntributions/50/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/50/ END:VEVENT BEGIN:VEVENT SUMMARY:Chemical networks for Protoplanetary Disk Gas Dynamics DTSTART;VALUE=DATE-TIME:20200514T091000Z DTEND;VALUE=DATE-TIME:20200514T093000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-48@meetings.aip.de DESCRIPTION:Speakers: Xuening Bai (Tsinghua University)\nI will discuss a few applications requiring coupling chemistry with gas dynamics in protopl anetary disks. The most common application is to obtain the level of ioniz ation\, which determines the coupling between gas and magnetic fields. In the bulk disk\, as far as ionization is concerned\, equilibrium chemistry holds unless sub-micron sized grains are depleted. This allows magnetic di ffusivities to be obtained from a pre-computed look-up table based on a co mplex chemical network\, although magnetic diffusivities could have non-tr ivial dependence on magnetic field strengths due to small dust grains. Mor e interesting applications involve the transport of chemical species over dynamical timescales\, such as those important for heating/cooling in the disk atmosphere\, which requires explicitly evolving a (reduced) chemical network with gas dynamics. We further show that a complex network can be r educed to a network with ~20-30 species with ~50-60 gas-phase reactions th at still reasonably reproduces the abundances of most major species of int erest in the disk atmosphere of the bulk midplane region. However\, the in termediate layer is more complex\, which may pose a challenge to chemo-dyn amical studies.\n\nhttps://meetings.aip.de/event/1/contributions/48/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/48/ END:VEVENT BEGIN:VEVENT SUMMARY:Interpreting emission line diagnostics of disc winds DTSTART;VALUE=DATE-TIME:20200514T084500Z DTEND;VALUE=DATE-TIME:20200514T090500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-9@meetings.aip.de DESCRIPTION:Speakers: Barbara Ercolano (USM/LMU\, Munich)\nWinds from plan et forming discs can be photoevaporative or magnetically driven. Both typ es of wind can remove mass from the disc and affect the surface density ev olution of the planet making material. A basic difference between these tw o types of wind is that magnetic winds\, unlike photoevaporative winds can also remove angular momentum and thus drive accretion in the system. Inde ed a departure from the classic alpha disc model is gaining momentum in th e field and is one of the main topics of this workshop. Unfortunately\, bo th photoevaporation and MHD numerical modes have yet to be observationally constrained and their relative contribution to the evolution of discs at various ages is still uncertain. In this contribution I will discuss curre ntly observed disc wind diagnostics and present past and current efforts i n modelling these lines using state-of-the-art theoretical models as well as analytical prescriptions.\n\nhttps://meetings.aip.de/event/1/contributi ons/9/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/9/ END:VEVENT BEGIN:VEVENT SUMMARY:On the migration of giant mass planets in 3D disks accreting from surface layers DTSTART;VALUE=DATE-TIME:20200513T115500Z DTEND;VALUE=DATE-TIME:20200513T121500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-44@meetings.aip.de DESCRIPTION:Speakers: Elena Lega ()\nThe classic view of a viscous disk\, where viscosity is generated by strong turbulence driven by the magneto ro tational instability\, is challenged by modern magneto-hydrodynamic simula tions. Disks are probably much less viscous than previously thought. Never theless\, disks cannot be in-viscid\, a minimum viscosity is set for examp le by the so-called vertical shear instability (VSI). In addition\, disk w inds remove angular momentum from thin surface layers of the proto-planeta ry disk\, promoting fast radial transport of gas towards the central star in these layers. This radial transport accounts for the observed stars' a ccretion rate.\nIn a classical viscous disk with radial transport correspo nding to observed stellar accretion rate\, giant planets migrate towards the star and easily become hot Jupiters with short orbital period. Howeve r\, the majority of observed giant planets have distances of 1-3AU from th eir parent star.\nThis contradiction has been investigated looking at a va riety of migrations mechanisms\, but no general mechanism to reduce planet migration has been found.\nThe new paradigm of disks with small bulk vis cosity and fast radial advection in surface offers a different perspective of the problem.\nConsequently\, we perform 3D numerical simulations using the FARGOCA code. We simulate the effect of disk wind by imposing a loss of angular momentum generating a desired mass flux in a thin surface laye r.\nWe show that planets migration is only marginally affected by the fas t gas in the thin layers and that the migration speed is mainly regulated by the bulk viscosity of the disk. However\, the migration rate measured w ith a bulk viscosity of alpha=1.e-4 (typically of the order of that genera ted by the VSI in the outer disk) is still too fast to understand the ob served radial distribution of extra-solar planets. Decreasing further the viscosity seems necessary for the understanding of the observations.\n\n https://meetings.aip.de/event/1/contributions/44/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/44/ END:VEVENT BEGIN:VEVENT SUMMARY:Non-equilibrium dynamics of massive embedded planetary systems DTSTART;VALUE=DATE-TIME:20200513T124500Z DTEND;VALUE=DATE-TIME:20200513T130500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-52@meetings.aip.de DESCRIPTION:Speakers: Thomas Rometsch (University of Tübingen)\nRecently\ , young planets with masses around $10\\\,M_\\text{Jupiter}$ which are sti ll embedded in a disk have been observed\, e.g. in the PDS 70 system. At t his mass range\, the planet-disk interaction is non-linear and the planets are attributed with having carved the observed gap into their parent disk . One possible scenario for the formation of large gaps is outward migrati on in 2:1 mean motion resonance (MMR) where the inner planet is more massi ve than the outer one. This process is known to strongly excite the planet s' eccentricities which in turn leads to eccentric gaps. The latter could be an observable feature of such systems. \n\nWe perform 2D\, vertically i ntegrated hydrodynamics simulations to study the migration and dynamics of the embedded planetary system employing a viscous $\\alpha$-disk model. T o avoid artificial wave-damping boundary conditions we choose large outer disk radii and work in the center of mass frame of the planetary system. I n addition to the often used locally isothermal equation of state\, we run simulations with radiative cooling\, viscous heating and irradiation from the star from which temperature distributions in the perturbed disk can b e extracted.\n\nThe simulations exhibit the expected smooth 2:1 MMR outwar d migration. For sufficiently high surface densities of the order of the m inimum mass solar nebula we additionally observe epochs of fast migration. During a sequence which we call migration jumps\, the outer planet underg oes fast outward migration traveling tens of au outward. It stays at the l arge distance for some kyr before returning back into the 2:1 MMR via fast inward migration. The whole sequence only takes 10-20 kyr. Meanwhile the inner planet remains relatively unaffected. A migration jump causes strong perturbations in the disk including pronounced spiral arms and asymmetric features including vortices and mass accumulation in the Lagrange points inside the gap region. The latter might be an observational indication for this process.\n\nDue to the large mass of the embedded planets\, the feat ures created in the disk are strong and synthetic observations of the simu lations might help to identify whether these mechanisms are at play in the disks we observe. In addition\, migration jumps of massive planets can be expected to cause strong scattering of dust particles and small bodies in the radial range on which the jumps occur. Thereby\, they might play an i mportant role for the dust and small body distribution in the earlier stag es of the systems lifetime.\n\nhttps://meetings.aip.de/event/1/contributio ns/52/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/52/ END:VEVENT BEGIN:VEVENT SUMMARY:Giant planet migration in low-viscosity disks DTSTART;VALUE=DATE-TIME:20200513T122000Z DTEND;VALUE=DATE-TIME:20200513T124000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-40@meetings.aip.de DESCRIPTION:Speakers: Alessandro Morbidelli (OCA)\nGiant planet migration (a.k.a. Type-II migration) should occur with a migration speed proportiona l to the disk's viscosity. This has been verified for alpha-disks with alp ha>1.e-4 (Robert et al.\, 2018). But what happens in disks with vanishing viscosity? Does Type-II migration stalls? A variety of behaviors have been observed in the literature for migration in low-viscosity disks. Migratio n seems to be very stochastic\, with very fast migration episodes (e.g. Mc Nally et al.\, 2018). However\, most simulations so far have been conduc ted in 2D disks. We find that low-viscosity 3D disks are much more stable than 2D disks of equivalent viscosity when they are perturbed by a planet\ , because they are submitted to the constraint of vertical hydrostatic equ ilibrium. Consequently giant planet migration in 3D disks behaves more reg ularly. Nevertheless\, the presence of vortex formed at the outer edge of the gap opened by the planet affects the planet evolution. We have investi gated in details the influence of a vortex on planet migration and on the growth of the planet's orbital eccentricity as well as the feedback of the eccentricity on migration.\n\nhttps://meetings.aip.de/event/1/contributio ns/40/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/40/ END:VEVENT BEGIN:VEVENT SUMMARY:Observational signatures of tightly-wound spirals driven by buoyan cy resonance DTSTART;VALUE=DATE-TIME:20200513T113000Z DTEND;VALUE=DATE-TIME:20200513T115000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-25@meetings.aip.de DESCRIPTION:Speakers: Jaehan Bae (Carnegie Institution of Washington)\nSpi ral waves are one of the most fundamental outcomes of planet-disk interact ion. In addition to the well-known Lindblad resonance\, buoyancy resonance \, which occurs when the vertical buoyancy frequency of disk gas matches w ith an integer multiple of the planet's orbital frequency\, can excite spi ral waves. Based on three-dimensional global hydrodynamic simulations and synthetic ALMA line observations\, we will show that buoyancy spirals can produce observable kinematic signatures. One of the main characteristics o f buoyancy spirals is their tightly-wound morphology (i.e.\, a small pitch angle compared with Lindblad spirals). The strength and observability of buoyancy spirals depend sensitively on the disk thermodynamics. This highl ights the importance of using more realistic thermodynamics in hydrodynami c simulations.\n\nhttps://meetings.aip.de/event/1/contributions/25/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/25/ END:VEVENT BEGIN:VEVENT SUMMARY:Planet Formation By Chondrule Accretion DTSTART;VALUE=DATE-TIME:20200513T093500Z DTEND;VALUE=DATE-TIME:20200513T095500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-46@meetings.aip.de DESCRIPTION:Speakers: Åke Nordlund (Niels Bohr Institute\, Copenhagen)\nR ecently performed nested-grid\, high-resolution hydrodynamic and radiation -hydrodynamics simulations of gas and particle dynamics in the vicinity of Mars- to Earth-mass planetary embryos (Popovas et al 2018MNRAS.479.5136P and 2019MNRAS.482L.107P) have provided quantitatively robust estimates of accretion rates for planet embryos formed inside a pressure trap. The simu lations extended from the resolved surfaces of the embryos to several vert ical disk scale heights\, with a vertical dynamic range exceeding 1e5. He ating due to the accretion of solids caused vigorous convective motions\, however even convection driven by a nominal accretion rate one Earth mass per Myr did not significantly alter the pebble accretion rate. Ray-trac ing radiative transfer showed that rocky planet embryos embedded in protop lanetary disks can retain hot and light atmospheres throughout much of the evolution of the disks.\n\nImportantly\, the results showed that particle s larger than the chondrules ubiquitously observed in meteorites are not required to explain the accretion of rocky planets such as Earth and Mars within the lifetime of the disk. Due to cancellation effects\, accretion rates of a given size particles are nearly independent of disk surface de nsity\, while proportional to the dust-to-gas ratio. As a result\, accura te growth times for specified particle sizes may be estimated. For 0.3-1 m m size particles\, and assuming a dust-to-gas ratio of 1:100\, the growth time from a small seed is ~1.5 million years for an Earth mass planet at 1 AU and ~1 million years for a Mars mass planet at 1.5 AU. \n\nThe magnitu de and robustness of the accretion rate estimates hinges on the assumption of the embryo residing in a pressure trap. A vertically projected dust to gas ratio of 1:100 is thus a lower limit\, with continued trapping of m m-size particles expected to accelerate accretion. This mechanism is the refore a prime candidate to explain rapid formation of rocky planets\, lea ving open only the question of by which mechanism the accretion is quenche d\, thus determining the final mass.\n\nI will discuss provocative scenari os where this question is resolved\, including implications for the format ion of gas dwarfs and gas giants.\n\nhttps://meetings.aip.de/event/1/contr ibutions/46/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/46/ END:VEVENT BEGIN:VEVENT SUMMARY:Evolution and growth of dust grains in protoplanetary disks with m agnetically driven disk wind DTSTART;VALUE=DATE-TIME:20200513T091000Z DTEND;VALUE=DATE-TIME:20200513T093000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-42@meetings.aip.de DESCRIPTION:Speakers: Tetsuo Taki (National Astronomical Observatory of Ja pan)\nMagnetically driven disk winds (MDWs) are one of the promising mecha nisms of dispersal processes of protoplanetary disks (Suzuki et al. 2010\, Bai 2013). When the MDWs play a key role\, the gaseous component of proto planetary disks evolves in a different manner from that of the classical v iscous evolution. As a result\, the subsequent planet formation is also af fected by the MDWs. In this work\, we investigate the effects of the MDWs on the radial drift of solid particles with a size of 0.1$\\mu$m - 1km. We propose that the MDWs is a possible solution to the ``radial drift barrie r'' of collisionally growing dust grains\, which is a severe obstacle to t he planet formation (e.g.\, Nakagawa et al.1986).\nIn order to study the e volution of dust grains in the disks\, we calculate the advection and coll isional growth of dust particles in evolving protoplanetary disks under th e 1+1 D (time + radial distance) approximation. We solve a coagulation equ ation of solid particles under a single-size approximation (Sato et al. 20 16) for various conditions of turbulent viscosity\, the mass loss by the M DW\, and the magnetic braking by the MDW.\nWe found that significant grain growth occurs in the inner region of the protoplanetary disks. The grown dust particles are larger than the km-sized bodies and they are no longer caught by the radial drift barrier. The mechanism of such successful dust growth is separated into two parts: (1) the increase of the equilibrium si ze of the dust particles caused by the convergent flow of the dust mass an d dispersal of the gas component\, (2) the unstable dust growth driven by the feedback loop between the size\, radial drift velocity\, and surface d ensity of the dust component. The disk evolution owing to the MDWs strongl y supports the former part of the growth mechanism. When the equilibrium s ize of the dust particles reaches the size that the Stokes number of the d ust particles exceeds unity\, the dust size evolution shift to the unstabl e mode (i.e.\, the latter part).\nBecause of the successful growth of dust particles\, the ring-like structure containing the planetesimal sized bod ies can be formed at the inner part of the protoplanetary disks. We will d iscuss the effects of such the ring-like structure on the subsequent plane tary system formation and the disk observations.\n\nhttps://meetings.aip.d e/event/1/contributions/42/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/42/ END:VEVENT BEGIN:VEVENT SUMMARY:Radiative effects in protoplanetary disks: planet-disk interaction DTSTART;VALUE=DATE-TIME:20200513T075000Z DTEND;VALUE=DATE-TIME:20200513T081000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-38@meetings.aip.de DESCRIPTION:Speakers: Alexandros Ziampras (University of Tuebingen)\nRecen t ALMA observations revealed concentric annular structures in several youn g\, class-II objects. Some have been modeled numerically with a single emb edded planet assuming a locally isothermal equation of state\, a method of ten used in the irradiation-dominated outer disk regions. We compare local ly isothermal and radiative disks similar to HD 163296 and AS 209 with emb edded planets and\nshow that the disk thermodynamics can impact the number of rings and the contrast of spirals produced by a planet. Radiative effe cts can suppress features visible in locally isothermal simulations. These results suggest the need for multiple planets to explain the ring-rich st ructures in such systems.\n\nhttps://meetings.aip.de/event/1/contributions /38/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/38/ END:VEVENT BEGIN:VEVENT SUMMARY:Investigating a new paradigm for type II migration DTSTART;VALUE=DATE-TIME:20200513T072500Z DTEND;VALUE=DATE-TIME:20200513T074500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-60@meetings.aip.de DESCRIPTION:Speakers: Dylan Kloster (OCA)\nUnderstanding the origins and d ynamics of massive planets during the planet-formation process is essentia l to understanding how the structures of individual planetary systems came to be. Massive planets have the ability to open gaps in their host disk\ , and the radial movements of these gap-opening planets is typically refer red to as type II migration. In the classical view\, a protoplanetary dis k accretes onto its star on a viscous timescale\, carrying this gap inward s with the planet moving with the gap. This theory assumes that the plane t remains in a state of quasi-equilibrium at the center of the gap. Howeve r\, a non-zero torque from the disk must be applied to the planet for it t o move radially\, meaning the planet is not necessarily located at equilib rium. This implies that while the gap is in motion\, and the planet is be ing dragged along with it\, the location of the planet is not necessarily at the center of the gap. In addition\, if we define the location of the gap center to be the radial position of a planet with a fixed orbit (i.e.\ , a non-migrating planet)\, we also consider the possibility that the equi librium position of the planet differs from this center. We explore these properties involving the gap-planet interaction of an evolving protoplane tary disk with 2D simulations using the FargOCA hydrodynamics code. We ac complish this by fixing the orbital radius of a massive planet ($M_p/M_* = 0.001$) until its disk has reached a steady state. At this stage we rele ase the planet from its fixed orbit\, and allow it to migrate freely. We then analyze the planet's displacement from equilibrium\, as well as its d isplacement from the gap center\, varying disk properties such as aspect r atio and viscosity\, and explore their effects on the planet migration rat e.\n\nhttps://meetings.aip.de/event/1/contributions/60/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/60/ END:VEVENT BEGIN:VEVENT SUMMARY:40 years of disk-planet interaction: some new developments in an o ld problem DTSTART;VALUE=DATE-TIME:20200513T070000Z DTEND;VALUE=DATE-TIME:20200513T072000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-8@meetings.aip.de DESCRIPTION:Speakers: Roman Rafikov (University of Cambridge)\nGravitation al coupling between protoplanetary disks and embedded planets is an old pr oblem ascending to the seminal studies of Goldreich & Tremaine (1980) and Lin & Papaloizou (1979). It is widely recognized as playing a key role in many areas of exoplanetary science: determination of the planetary archite ctures\, disk evolution\, planetary accretion\, and so on. In this talk I will describe several key theoretical advances that took place in this fie ld in recent years. They provide a better understanding of the ways in whi ch density waves get excited in disks by planets\, how they propagate thro ugh the disk\, and how they dissipate\, linearly and non-linearly\, drivin g global disk evolution. I will particularly focus on recent advances in i ncorporating realistic disk thermodynamics in studies of disk-planet coupl ing\, their impact on the numerical studies of this phenomenon\, and the o bservational manifestations of massive planets in protoplanetary disks\, i ncluding both scattered light imaging and recent ALMA observations of fine structures in disks.\n\nhttps://meetings.aip.de/event/1/contributions/8/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/8/ END:VEVENT BEGIN:VEVENT SUMMARY:What can we learn from ALMA polarimetric observations of protoplan etary disks? DTSTART;VALUE=DATE-TIME:20200512T142500Z DTEND;VALUE=DATE-TIME:20200512T144500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-14@meetings.aip.de DESCRIPTION:Speakers: Akimasa Kataoka (National Astronomical Observatory o f Japan)\nPolarimetric observations of protoplanetary disks at millimeter wavelengths have been dramatically developing owing to its high-sensitivit y and high-resolution observations with ALMA. However\, the mechanisms of the polarization are under discussion. The proposed mechanisms so far are the self-scattering and the grain alignment\, but the alignment directions are possibly with magnetic fields\, with radiation fields\, or with gas-d rag directions. In this talk\, I first review the possible mechanisms that may produce the millimeter polarization\, and then present the case studi es of different disks. On the lopsided disk of HD 142527\, we found that t he magnetic fields are dominated by the toroidal components at least in th e south regions. On the ring-gap disk of HD 163296\, by modeling the self- scattering polarization\, we found that the dust scale height is lower in the inner regions\, which indicates the low turbulence of gas in the inner disk and is consistent with the concept of magnetic dead zone. I also dis cuss possible constraints on the grain dynamics on AS 209 and HL Tau by mo deling the gas-flow aligned dust grains.\n\nhttps://meetings.aip.de/event/ 1/contributions/14/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/14/ END:VEVENT BEGIN:VEVENT SUMMARY:ALMA chemical survey of Disk-Outflow sources in Taurus DTSTART;VALUE=DATE-TIME:20200512T145000Z DTEND;VALUE=DATE-TIME:20200512T151000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-18@meetings.aip.de DESCRIPTION:Speakers: Antonio Garufi ()\nALMA-DOT is a small campaign devo ted to the chemical characterization of disk-outflow sources in Taurus. Th e sample currently consists of six Class I sources known to drive powerful outflows. The high angular resolution and sensitivity of ALMA allowed us to characterize their chemical composition by separating the disk emission from the outflow and envelope contamination. Six molecules - from carbon monoxyde to the simple organic formaldehyde and methanol - have been surve yed in each target. I present the results of the survey\, shedding light o n (i) the timescale for the formation of dust and gas sub-structures\, (ii ) the morphological interplay of dust and gas\, (iii) the role of disk-fee ding filaments\, (iv) the distribution and formation mechanism of simple o rganic molecules\, and (v) the chemical composition of molecular outflows. Young sources like those probed by ALMA-DOT offer the best laboratory to study how soon are planets formed and how are complex molecules delivered to the (assembling) planetary atmospheres.\n\nhttps://meetings.aip.de/even t/1/contributions/18/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/18/ END:VEVENT BEGIN:VEVENT SUMMARY:The polarizing puzzle of dusty disks DTSTART;VALUE=DATE-TIME:20200512T140000Z DTEND;VALUE=DATE-TIME:20200512T142000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-10@meetings.aip.de DESCRIPTION:Speakers: Gesa H.-M. Bertrang (MPIA)\nFrom a theoretical point -of-view\, magnetic fields are crucial to the evolution of planet-forming disks. However\, profound observational constraints are pending. Presently \, the number of cutting-edge polarization observations presenting inconcl usive data increases continuously. In very recent years\, polarization at mm-wavelengths\, the classical tracer of magnetic fields\, emerged as high ly ambiguous\, and the pressing demand for comprehensive tools to analyze these new observations is growing.\n\nI will present an overview on the so urces of continuum polarization with focus on the impact of grain alignmen t\, scattering\, and grain porosity on the polarization measurement – as well as a potential solution to this dusty ambiguousness\, linearly polar ized gas emission.\n\nhttps://meetings.aip.de/event/1/contributions/10/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Global axisymmetric simulations of photoevaporation and magnetical ly driven protoplanetary disk winds DTSTART;VALUE=DATE-TIME:20200512T115500Z DTEND;VALUE=DATE-TIME:20200512T121500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-21@meetings.aip.de DESCRIPTION:Speakers: Peter Rodenkirch (Institute for Theoretical Astrophy sics Heidelberg)\nPhotoevaporation and magnetically driven winds are two i ndependent mechanisms that remove mass from protoplanetary disks. In addit ion to accretion\, the effect of these two principles acting concurrently could be significant\, and the transition between them has not yet been ex tensively studied and quantified. \nIn order to contribute to the understa nding of disk winds\, we present the phenomena emerging in the framework o f two-dimensional axisymmetric\, nonideal magnetohydrodynamic simulations including extreme-ultraviolet (EUV) and X-ray driven photoevaporation. Of particular interest are the examination of the transition region between p hotoevaporation and magnetically driven wind\, the possibility of emerging magnetocentrifugal wind effects\, and the morphology of the wind itself\, which depends on the strength of the magnetic field. \nWe used the PLUTO code in a two-dimensional axisymmetric configuration with additional treat ment of EUV and X-ray heating and dynamic ohmic diffusion based on a semi- analytical chemical model. \nWe determine that the transition between the two outflow types occurs for values of the initial plasma beta β ≥ 107\ , while magnetically driven winds generally outperform photoevaporation fo r stronger fields. In our simulations we observe irregular and asymmetric outflows for stronger magnetic fields. In the weak-field regime\, the phot oevaporation rates are slightly lowered by perturbations of the gas densit y in the inner regions of the disk. Overall\, our results predict a wind w ith a lever arm smaller than 1.5\, consistent with a hot magnetothermal wi nd. Stronger accretion flows are present for values of β \n\nhttps://meet ings.aip.de/event/1/contributions/21/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/21/ END:VEVENT BEGIN:VEVENT SUMMARY:Radiation-Hydrodynamical Models of X-ray Photoevaporation in Carbo n Depleted Circumstellar Discs DTSTART;VALUE=DATE-TIME:20200512T124500Z DTEND;VALUE=DATE-TIME:20200512T130500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-49@meetings.aip.de DESCRIPTION:Speakers: Lisa Wölfer (Max-Planck-Institut für extraterrestr ische Physik)\nTransition discs provide an important tool to probe various mechanisms that might influence the evolution of protoplanetary discs and therefore the formation of planetary systems. One of these mechanisms is photoevaporation due to energetic radiation from the central star\, which can in principal explain the occurrence of discs with inner cavities. Curr ent models\, however\, fail to reproduce a subset of the observed transiti on discs\, namely objects with large measured cavities and vigorous accret ion. For these objects the presence of (multiple) giant planets is often i nvoked to explain the observations. In our work\, we explore the possibili ty of X-ray photoevaporation operating in discs with different gas-phase d epletion of carbon and show that the influence of photoevaporation can be extended in such low-metallicity discs. As carbon is one of the main contr ibutors to the X-ray opacity\, its depletion leads to larger penetration d epths of X-rays in the disc and results in higher gas temperatures and str onger photoevaporative winds. We present radiation-hydrodynamical models o f discs irradiated by internal X-ray+EUV radiation assuming carbon gas-pha se depletions by factors of 3\,10 and 100 and derive realistic mass-loss r ates and profiles. Our analysis yields robust temperature prescriptions as well as photoevaporative mass-loss rates and profiles which may be able t o explain a larger fraction of the observed diversity of transition discs. \n\nhttps://meetings.aip.de/event/1/contributions/49/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/49/ END:VEVENT BEGIN:VEVENT SUMMARY:Thermal evolution of protoplanetary disks: from beta-cooling to de coupled gas and dust temperatures DTSTART;VALUE=DATE-TIME:20200512T131000Z DTEND;VALUE=DATE-TIME:20200512T133000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-29@meetings.aip.de DESCRIPTION:Speakers: Eduard Vorobyov (University of Vienna)\nThermal proc esses can play an important role in dynamics\, chemistry\, and dust growth of protoplanetary disks. Using numerical hydrodynamics simulations in th e thin-disk limit\, we explore different approaches to computing the disk thermal structure: a simplified beta-cooling approach\, in which the rate of disk cooling is proportional to the local dynamical time\, a fiducial m odel with equal dust and gas temperatures calculated taking viscous heatin g\, irradiation\, and radiative \ncooling into account\, and also a more s ophisticated approach allowing for decoupled dust and gas temperatures. We found that the gas temperature may significantly exceed that of dust in t he outer regions of young protoplanetary disks. The outer envelope\, howev er\, shows an inverse trend with the gas temperatures dropping below that of dust. Models with a constant beta-parameter fail to reproduce the disk evolution with more sophisticated thermal schemes.\nWe discuss whether the temperature decoupling is important for the gas dynamics\,\nchemical evol ution\, and dust growth in young protoplanetary disks.\n\nhttps://meetings .aip.de/event/1/contributions/29/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/29/ END:VEVENT BEGIN:VEVENT SUMMARY:TACOs\, thermally-assisted (magneto-)centrifugal outflows DTSTART;VALUE=DATE-TIME:20200512T122000Z DTEND;VALUE=DATE-TIME:20200512T124000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-54@meetings.aip.de DESCRIPTION:Speakers: Oliver Gressel (AIP)\nLaminar outflows driven by lar ge-scale magnetic fields likely play an important role in the evolution an d dispersal of protoplanetary disks\, and in setting the conditions for pl anet formation. Extending our previous non-ideal MHD model with radiative transfer as well as a simplified thermochemistry\, we follow the dual aim of studying the influence of thermal driving and\, at the same time\, layi ng the foundation for synthetic observations. Our simulations develop magn etocentrifugal outflows that are primarily driven by magnetic tension forc es. As a consequence\, the mass-loss rate in the wind only increases moder ately when including thermochemical effects. For typical field magnitudes\ , magnetic dissipation heating remains sub-dominant compared with thermoch emical and irradiation heating. We\, moreover\, follow the evolution of th e entrained vertical magnetic flux and find it to diffuse out of the disk on secular timescales as a result of non-ideal MHD. Based on line-radiativ e post processing\, we demonstrate that velocity spectra and moment 1 maps of O and CS (as well as other molecules) show significant\, potentially o bservable differences between models with and without outflows. In particu lar the shape of the line profiles\, and velocity asymmetries in the momen t 1 maps could enable the identification of outflows emanating from the su rface of a disk.\n\nhttps://meetings.aip.de/event/1/contributions/54/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/54/ END:VEVENT BEGIN:VEVENT SUMMARY:Radiation Hydrodynamics Simulations of Photoevaporating Protoplane tary Disks with Multi-Metallicity Chemistry DTSTART;VALUE=DATE-TIME:20200512T113000Z DTEND;VALUE=DATE-TIME:20200512T115000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-6@meetings.aip.de DESCRIPTION:Speakers: Riouhei Nakatani (RIKEN)\nRecent observations have f ound shorter lifetimes of protoplanetary disks (PPDs) in low-metallicity e nvironments than in the solar neighborhood (Yasui et al. 2009\, 2010). It suggests a more efficient disk dispersal with decreasing metallicity. Prio r studies have shown that photoevaporation is one of the essential disk-di spersing mechanisms that can yield sufficient mass-loss rates consistent w ith observed disk lifetimes. Ercolano & Clarke (2010) have demonstrated th at EUV/X-ray photoevaporation potentially explains the shorter disk lifeti mes for low-metallicity PPDs. \n In our studies\, we implement photoelectr ic heating due to FUV as well as photoionization heating due to EUV/X-ray and examine the effects on thermochemical structures PPDs. We perform a su ite of radiation hydrodynamics simulations\, varying disk metallicities\, to study the effects of metallicity on thermochemical structures and photo evaporation. Our simulations self-consistently solve hydrodynamics\, radia tive transfer\, and nonequilibrium chemistry. We also consistently determi ne grain temperatures with 2D radiative transfer. \n The results show incr easing mass-loss rates as metallicity decreases at sub-solar metallicities owing to the reduced opacity of the disk. It is consistent with the obser vational trend that the lifetimes are shorter in low metallicity environme nts. At even lower metallicities\, dust-gas collisional cooling remains ef ficient compared to FUV photoelectric heating. The disk temperatures are t oo low to drive strong photoevaporation regardless of FUV heating. For fur ther lower metallicities\, dynamical time is shorter than the heating or c ooling timescale\, and thus the atmosphere of PPDs becomes effectively adi abatic. Overall\, our results show metallicity significantly affects the t hermochemical structures and dynamics of the PPD atmosphere.\n\nhttps://me etings.aip.de/event/1/contributions/6/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Electric heating in laminar protoplanetary disks DTSTART;VALUE=DATE-TIME:20200512T093500Z DTEND;VALUE=DATE-TIME:20200512T095500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-30@meetings.aip.de DESCRIPTION:Speakers: William Béthune (University of Tübingen)\nObservat ions point toward weak levels of turbulence in protoplanetary disks\, and theoretical studies now focus on magneto-thermal winds rather than MRI tur bulence as the main driver of mass accretion. Although MHD turbulence migh t be quenched\, laminar magnetic structures may still transport angular mo mentum and induce substantial accretion heating inside the disk. Using ste ady-state radiative MHD models\, I will show how magnetic fields can impac t the thermal structure of the inner disk despite extremely low ionization fractions.\n\nhttps://meetings.aip.de/event/1/contributions/30/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/30/ END:VEVENT BEGIN:VEVENT SUMMARY:The Inner Regions of Protoplanetary Disks: 3D Radiation Magneto-Hy drodynamical Models DTSTART;VALUE=DATE-TIME:20200512T091000Z DTEND;VALUE=DATE-TIME:20200512T093000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-34@meetings.aip.de DESCRIPTION:Speakers: Mario Flock (MPIA)\nMany planets orbit within an AU of their stars\, raising questions about their origins. Particularly puzzl ing are the planets found near the silicate sublimation front. We investig ate conditions near the front in the protostellar disk around a young inte rmediate-mass star\, using the first global 3-D radiation non-ideal MHD si mulations in this context. \n\nThe results show magnetorotational turbule nce around the sublimation front at 0.5 AU. Beyond 0.8 AU is the dead zon e\, cooler than 1000 K and with turbulence orders of magnitude weaker. A local pressure maximum just inside the dead zone concentrates solid partic les\, allowing for efficient growth. Over many orbits\, a vortex develops at the dead zone's inner edge\, increasing the disk's thickness locally b y around 10%.\n\nWe synthetically observe the results using Monte Carlo tr ansfer calculations\, finding the sublimation front is bright in the near- infrared. The models with vertical magnetic flux develop extended\, magne tically-supported atmospheres that reprocess extra starlight\, raising the near-infrared flux 20%. The vortex throws a non-axisymmetric shadow on t he outer disk. \n\nRadiation-MHD models of the kind we demonstrate open a new window for investigating protoplanetary disks' central regions. They are ideally suited for exploring young planets' formation environment\, i nteractions with the disk\, and orbital migration\, in order to understand the origins of the close-in exoplanets.\n\nhttps://meetings.aip.de/event/ 1/contributions/34/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/34/ END:VEVENT BEGIN:VEVENT SUMMARY:Atomic oxygen and warm CO in magnetothermal winds DTSTART;VALUE=DATE-TIME:20200512T084500Z DTEND;VALUE=DATE-TIME:20200512T090500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-5@meetings.aip.de DESCRIPTION:Speakers: Jeremy Goodman (Princeton University)\nForbidden lin es of atomic oxygen at 6300 and 5577 Angstroms and rovibrational lines of CO near 4.7 microns are relatively strong and well-observed in T Tauri sta rs. The oxygen lines have been touted as the ``smoking gun" of photoevapo rative winds\, but after considering the requirements for their excitation \, we conclude that they are at least as likely to form in magnetothermal winds such as those modeled recently by Wang and collaborators. The CO li ne profiles are more often single- rather than double-peaked\, with rotati onal temperatures of 300-1000 K\, and are probably excited by IR or UV pum ping rather than collisions. These lines are difficult to explain by phot oevaporative winds\, and are more naturally produced by magnetothermal one s.\n\nhttps://meetings.aip.de/event/1/contributions/5/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Protoplanetary Disk Chemodynamics as a Scale for Weighing Young St ars and Planets DTSTART;VALUE=DATE-TIME:20200512T075000Z DTEND;VALUE=DATE-TIME:20200512T081000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-41@meetings.aip.de DESCRIPTION:Speakers: Patrick Sheehan (Northwestern University)\nMuch of o ur understanding of star and planet formation hinges on the accuracy of st ellar masses and ages derived from pre-main sequence evolutionary track mo dels. Consequently\, errors in evolutionary track models could propagate t hrough much of our understanding of star and planet formation. Moreover\, there remain few constraints on pre-main sequence evolutionary tracks owin g in large part to the lack of pre-main sequence stars with precisely meas ured masses. Fortunately\, Keplerian rotation in protoplanetary disks pro vides an avenue towards directly measuring the masses of young stars\, and therefore could provide large samples of well measured masses with which to constrain evolutionary tracks. I will present my efforts using radiativ e transfer forward modeling of ALMA spectral line observations\, in conjun ction with precise distance measurements from Gaia that are used to break the stellar mass-distance degeneracy\, to directly measure pre-main sequen ce stellar masses with precisions as high as 2%. I will also present effor ts to extend these methods to measure stellar masses for embedded protosta rs\, where the traditional method of estimating masses from evolutionary t racks can be impossible\, as well as an attempt to directly measure the ma ss of a young purported protoplanet.\n\nhttps://meetings.aip.de/event/1/co ntributions/41/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/41/ END:VEVENT BEGIN:VEVENT SUMMARY:Observed sizes of planet-forming disks trace viscous spreading DTSTART;VALUE=DATE-TIME:20200512T072500Z DTEND;VALUE=DATE-TIME:20200512T074500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-24@meetings.aip.de DESCRIPTION:Speakers: L. Trapman (Leiden University)\nThe evolution of pro toplanetary disks is set by the conservation of angular momentum\, where t he accretion of material onto the central star is balanced by viscous expa nsion of the outer disk or by disk winds extracting angular momentum witho ut changing the disk size. Studying the time evolution of disk sizes allow s us therefore to distinguish between viscous stresses or disk winds as th e main mechanism of disk evolution. Observationally\, estimates of the dis k gaseous outer radius are based on the extent of the CO rotational emissi on\, which\, during the evolution\, is also affected by the changing physi cal and chemical conditions in the disk.\nWe have used physical-chemical m odels to study how the extent of the CO emission changes with time in a vi scously expanding disk. We find that the gas outer radius ($R_{\\rm CO\,\\ 90\\%}$) measured from our models matches the expectations of a viscously spreading disk: $R_{\\rm CO\,\\ 90\\%}$ increases with time and for a giv en time $R_{\\rm CO\,\\ 90\\%}$ is larger for a disk with a higher viscosi ty $\\alpha_{\\rm visc}$. However\, in the extreme case where the disk mas s is low ($ \\leq 10^{-4}\\ \\mathrm{M}_{\\odot}$) and $\\alpha_{\\rm visc }$ is high ($\\geq 10^{-2}$)\, $R_{\\rm CO\,\\ 90\\%}$ will instead decrea se with time as a result of CO photodissociation in the outer disk. \nWe f ind that most observed gas outer radii in Lupus can be explained using a v iscously evolving disk that starts out small $(\\simeq 10\\ \\mathrm{AU})$ and has a low viscosity $(\\alpha_{\\rm visc} = 10^{-4} - 10^{-3})$.\n\nh ttps://meetings.aip.de/event/1/contributions/24/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/24/ END:VEVENT BEGIN:VEVENT SUMMARY:Disk Spreading and Surface Accretion Flows in Protoplanetary Disks DTSTART;VALUE=DATE-TIME:20200512T070000Z DTEND;VALUE=DATE-TIME:20200512T072000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-7@meetings.aip.de DESCRIPTION:Speakers: Joan Najita (National Optical-Infrared Astronomy Res earch Laboratory)\nDespite its importance for star and planet formation\, the physical process(es) that drive disk accretion remain frustratingly un clear. The magnetorotational instability is questioned both theoretically and observationally and disk winds are increasingly invoked. I will descri be how the evolution of gas disk sizes from Class I to Class II indicates that some mechanism produces significant disk spreading (i.e.\, angular mo mentum transport within the disk) during the Class II phase. I will also s how results from high resolution mid-infrared spectroscopy of a Class I so urce that may provide evidence for an alternative angular momentum transpo rt mechanism\, “surface accretion flows\,” which have been reported in MHD simulations of magnetized disks.\n\nhttps://meetings.aip.de/event/1/c ontributions/7/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Cosmic-rays: a possible explanation for the difference of mean dis k sizes in star-forming regions DTSTART;VALUE=DATE-TIME:20200511T143500Z DTEND;VALUE=DATE-TIME:20200511T145500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-37@meetings.aip.de DESCRIPTION:Speakers: Michael Küffmeier (Zentrum für Astronomie Heidelbe rg (ZAH))\nSurveys of protoplanetary disks in star-forming regions of simi lar age revealed \nsignificant variations in average disk mass between som e regions. Disks in the Orion Nebular Cluster (ONC) and Corona Australis ( CrA) are on average a factor of a few smaller than disks observed in Lupus \, Taurus\, Chamaeleon I or Ophiuchus. We aim for an understanding of the physical mechanism behind this spread by testing the influence of cosmic-r ay ionization rates on the formation process of protoplanetary disks. We r un non-ideal magnetohydrodynamical protostellar collapse simulations assum ing different cosmic-ray ionization rates. We compute the resitivities for ambipolar diffusion and Ohmic dissipation with a chemical network. Consis tent with previous results\, our models demonstrate that a higher cosmic-r ay ionization rate leads to stronger magnetic braking\, and hence to the f ormation of smaller disks. Considering recent findings that protostars act as forges of comsic rays\, we show that a high average cosmic-ray ionizat ion rate in \nstar-forming regions like the ONC or CrA can explain the det ection of smaller disks in these regions. Our results show that on average a higher cosmic-ray ionization rate leads to the formation of smaller dis ks. Therefore\, smaller disks in regions of similar age can be the consequ ence of different levels of ionization\, and may not exclusively be caused by disk truncation via external photoevaporation. We strongly encourage o bservations that allow measuring the cosmic-ray ionization degrees in diff erent star-forming regions to test our hypothesis.\n\nhttps://meetings.aip .de/event/1/contributions/37/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/37/ END:VEVENT BEGIN:VEVENT SUMMARY:Observational Constraints on Envelope Ionization in Class I Protos tars DTSTART;VALUE=DATE-TIME:20200511T141000Z DTEND;VALUE=DATE-TIME:20200511T143000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-32@meetings.aip.de DESCRIPTION:Speakers: Kamber Schwarz (University of Arizona)\nIonization r ate is one of the most important parameters controlling both the chemical and dynamical processes in protoplanetary disks. What few observational co nstrains on ionization currently exists suggest overall low ionization\, l imiting the processes able to take place. I will present new NOEMA observa tions which\, when combined with chemical modeling\, are indicative of enh anced ionization rates in the envelopes of three Class I protostars. I wi ll then discuss the potential impact of this early enhancement on the evol ution of protoplanetary disks.\n\nhttps://meetings.aip.de/event/1/contribu tions/32/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/32/ END:VEVENT BEGIN:VEVENT SUMMARY:The regulation of angular momentum by non-ideal MHD DTSTART;VALUE=DATE-TIME:20200511T134500Z DTEND;VALUE=DATE-TIME:20200511T140500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-56@meetings.aip.de DESCRIPTION:Speakers: Pierre Marchand (American Museum of Natural History) \nMagnetic fields play a major role in the regulation of angular momentum during the protostellar collapse\, hence for the formation of the protopla netary disk. The magnetic braking is able to slow the rotation and extract the angular momentum from the disk. However\, this process is tampered by a decoupling between neutral and charged particles\, especially the ions through the ambipolar diffusion. The decoupling is heavily impacted by the chemistry at stake\, and particularly by the grain size distribution. I w ill show how a modification of the grain size distribution enhances the de coupling between the magnetic field and the gas\, and how it modifies the distribution and transport of angular momentum.\n\nhttps://meetings.aip.de /event/1/contributions/56/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/56/ END:VEVENT BEGIN:VEVENT SUMMARY:Constraining the Radial Turbulence Parameter $\\alpha$ from the Di stribution of Water and Refractory species in an Evolving Solar Nebula DTSTART;VALUE=DATE-TIME:20200511T121500Z DTEND;VALUE=DATE-TIME:20200511T123500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-53@meetings.aip.de DESCRIPTION:Speakers: Anusha Kalyaan (Clemson University)\nThe overall str ucture of the evolving protoplanetary disk is set by the interaction of ac cretion and dispersal processes such as turbulence\, winds and photoevapor ation (Ercolano & Pascucci 2017)\, with finer structural details (as gaps\ , cavities\, spirals and warps) in the disk provided by planet formation ( eg. Van der Marel et al. 2015). Recent meteoritic evidence from Kruijer et al. (2017) strongly suggest the presence of two distinct isotopic reservo irs in the \n\nhttps://meetings.aip.de/event/1/contributions/53/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/53/ END:VEVENT BEGIN:VEVENT SUMMARY:Are Protoplanetary Disks Truly Laminar? DTSTART;VALUE=DATE-TIME:20200511T115000Z DTEND;VALUE=DATE-TIME:20200511T121000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-28@meetings.aip.de DESCRIPTION:Speakers: Jacob Simon (Iowa State University)\nRecent years ha ve seen tremendous progress in our understanding of angular momentum trans port in protoplanetary disks. It is now thought that accretion is driven primarily by a large-scale vertical field threading the disk\, either thro ugh magnetically launched winds or large-scale magnetic stresses within th e disk plane. However\, it remains an open question as to just how lamina r these accreting disks are. Even if not the primary source of angular mo mentum transport\, turbulence may still play a crucial role in the multitu de of processes involved in forming planets. \n\nIn this talk\, I will pre sent both theoretical and observational evidence that protoplanetary disks are not necessarily laminar and in some cases can still harbor vigorous t urbulence. From ALMA observations of molecular line broadening\, we now know of at least one source that presents a clear signature of turbulence. I will present these compelling new observations and compare them to ear lier predictions of magnetically driven turbulence. I will also present a number of numerical experiments that indeed show magnetically driven turbu lence is still present throughout large regions of the disk\, even in the presence of a large-scale magnetic field. I will conclude with an outlook for future observational and theoretical studies and what the results so far imply for our understanding of planet formation and disk evolution.\n\ nhttps://meetings.aip.de/event/1/contributions/28/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/28/ END:VEVENT BEGIN:VEVENT SUMMARY:A systematic exploration of magnetised disc wind solutions in prot oplanetary discs DTSTART;VALUE=DATE-TIME:20200511T112500Z DTEND;VALUE=DATE-TIME:20200511T114500Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-20@meetings.aip.de DESCRIPTION:Speakers: Geoffroy Lesur (Institute of planetology and astroph ysics of Grenoble/CNRS)\nThe recent developments in our understanding of t he chemical composition\, the ionisation equilibrium and the dynamics of p rotoplanetary discs has led to the conclusion that magnetised disc wind (M DW) are probably playing an important role in shaping the long term evolut ion of these objects. Most of our understanding of these winds comes from global direct numerical simulations which include complex microphysics and which explore only a very limited subspace of parameters. Hence\, it is v ery difficult to draw firm conclusions about the long-term evolution of di scs subject to MDW. \n\nIn this contribution\, I will present a systematic exploration of MDW solutions\, which can then be used in secular models t o predict the evolution of a disc\, in a way similar to the "alpha disc" m odel. I will also discuss the solutions topology (top/down symmetry\, midp lane/surface accretion layers\, laminar stress\, etc...) which have often been mis-interpreted in the literature.\n\nhttps://meetings.aip.de/event/1 /contributions/20/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/20/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic flux transport in protoplanetary discs DTSTART;VALUE=DATE-TIME:20200511T110000Z DTEND;VALUE=DATE-TIME:20200511T112000Z DTSTAMP;VALUE=DATE-TIME:20240704T115455Z UID:indico-contribution-1-27@meetings.aip.de DESCRIPTION:Speakers: Philip Leung ()\nMagnetic effects are important for accretion disc dynamics. In PPDs\, much still needs to be understood in ho w non-ideal MHD effects (Ohmic\, Hall and ambipolar diffusion)\, which are relevant because of the low ionisation levels found in much of the disc\, affect the radial accumulation and retention of magnetic flux needed for processes such as the launching of a magnetic disc wind. I aim to present results from semi-analytic local models incorporating all three non-ideal effects\, and how they inform our understanding of the flux transport prob lem. I will also be presenting some recent numerical simulations exploring the interplay of these non-ideal effects with the magnetic field geometry \, and the resulting implications on the flux transport process.\n\nhttps: //meetings.aip.de/event/1/contributions/27/ LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) Lecture Hall URL:https://meetings.aip.de/event/1/contributions/27/ END:VEVENT END:VCALENDAR