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:20240704T115531Z UID:indico-contribution-6-51@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: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:20240704T115531Z UID:indico-contribution-6-21@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:20240704T115531Z UID:indico-contribution-6-49@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:20240704T115531Z UID:indico-contribution-6-29@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:20240704T115531Z UID:indico-contribution-6-54@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:20240704T115531Z UID:indico-contribution-6-6@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:20240704T115531Z UID:indico-contribution-6-30@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:20240704T115531Z UID:indico-contribution-6-34@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:20240704T115531Z UID:indico-contribution-6-5@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 END:VCALENDAR