37th XMM-SSC Consortium Meeting 2026

17 Mar 2026, 09:00 → 19 Mar 2026, 14:40 Europe/Berlin

Lecture Hall, Maria Margaretha Kirch Building (Leibniz Institute for Astrophysics Potsdam (AIP))

Illustration: ESA / Traulsen / AIP

The 37th consortium meeting of the XMM-Newton Survey Science Centre (XMM-SSC) will be held from March 17-19, 2026 at the Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany.

The XMM-SSC is an international consortium across several countries and was selected by ESA to facilitate exploiting XMM-Newton's survey capacities. The XMM-SSC and ESA teams develop the science analysis software suite and the serendipitous source catalogues. In preparation of the 5th catalogue generation, the 37th consortium meeting convenes consortium members, interested scientists from the consortium institutes, and ESA scientists to discuss XMM-Newton science and developments.

We look forward to seeing you in Potsdam.

XMM-SSC

xmmssc.irap.omp.eu xmmssc.aip.de

Local Organizing Committee

Iris Traulsen* Georg Lamer* Axel Schwope Adriane Chapman and helpers

_{* LOC recipients of e-mails to xmmssc2026}

Tuesday, 17 March

11:30 Lunch option

XMM-Newton & SAS status: Session 1

1 Welcome

Speakers: Natalie Webb (IRAP), Axel Schwope (AIP)

2 XMM-Newton mission status

Speaker: Felix Fuerst (ESA/ESAC)

3 Data exchanges between SOC & SSC

(remotely)

Speaker: John Hoar

4 SAS status and development

Speaker: Aitor Ibarra Ibaibarriaga (Telespazio UK for ESA (XMM-Newton SOC ESAC/ESA))

5 Pipeline status and summary of the bulk reprocessing

(remotely)

Speaker: Pedro Rodriguez

6 OM status

(remotely)

Speaker: Simon Rosen

7 EPIC MOS status

Speaker: Jean Ballet (AIM, CEA Saclay)

15:55 Coffee break - Photo

XMM-Newton & SAS status: Session 2

8 RGS status

Speaker: Aitor Ibarra Ibaibarriaga (Telespazio UK for ESA (XMM-Newton SOC ESAC/ESA))

9 EPIC pn status

(remotely)

Speaker: Michael Freyberg (MPE Garching, Germany)

10 NASA XMMGOF status and activities

(remotely)

Speaker: Brendan Perry

11 The XCatDB status and prospects

Speaker: Laurent Michel (ObAS)

12 The source-detector's view on 5XMM

AIP leads the development of the XMM-Newton source detection tasks and performs (stacked) source detections on all catalogue observations. This talk summarises the detection method chosen for the 5XMM catalogue, the related code changes, and the challenges and results of processing 14616 observations for 5XMM-DR15.

Speaker: Dr Iris Traulsen (Leibniz-Institut für Astrophysik Potsdam (AIP))

13 5XMM-DR15

(remotely)

Speaker: Mickaël Coriat (IRAP)

Satellite events: Babelsberg tour (group 1)

Satellite events: Meeting dinner

Wednesday, 18 March

Science Advisory Group: Session 3

14 Agent-Ready “Mini-SAS” Microservices for Language-Driven X-ray Data Analysis

We present Mini-SAS, a suite of purpose built, REST-API micro-services that wrap canonical XMM-Newton SAS tasks into agent friendly LLM tools, enabling language driven for reliable X-ray analysis. Each Mini-SAS targets one well scoped workflow, for example, image, spectra or lightcurve generation for all XMM-Newton instruments, with explicit inputs/outputs, provenance capture, and determinism.

The services advertise machine readable schemas to support autonomous tool use by AI agents, and they return structured results (metadata + science products) suitable for downstream analysis.

Beyond convenience wrappers, Mini-SAS integrates with XMMGPT via stable REST endpoints and back-ends for remote execution, its design enforces reproducibility and safety. We outline an evaluation plan spanning: (1) fidelity vs. reference SAS pipelines, (2) agent task-success and latency under realistic prompts, (3)
end-to-end user studies.

Finally, we sketch a roadmap to a mission agnostic X-ray AI framework (XMM-Newton → NewAthena), standardizing micro-services for spectra, timing, imaging, and source detection so language agents can compose cross-mission analyses while preserving scientific rigor. Mini-SAS thus bridges expert pipelines and
autonomous language agents, turning natural-language intent into auditable, high-quality X-ray results.

Speaker: Aitor Ibarra Ibaibarriaga (Telespazio UK for ESA (XMM-Newton SOC ESAC/ESA))

15 Highly Variable Sources in the XMM Slew Survey

The newest edition of the XMM Slew Survey catalogue incorporates more than eight years of new observations, adding nearly 70,000 new detections of sources on the previous version. With an extended baseline now covering more than 20 years of observations the Slew catalogue presents an opportunity to detect bright, long-period, variable sources.

By cross-matching the sources in the XMM Slew Catalogue v3 against ROSAT, eROSITA, XMM pointed observation and Swift source catalogues, and upper limits from some of these observatories, we have identified a large population of highly variable soft X-ray sources. In some cases these sources exhibit variability over several orders of magnitude, which is a strong indicator for astrophysical sources powered by compact objects. Many of these sources will not have been identified as significantly variable before. We will present the population of significantly variable sources, and identify several examples of X-ray sources which are ripe for further examination including at least one TDE candidate.

Speaker: Robbie Webbe (IRAP, Toulouse, France)

16 Extreme ends of AGN variability

(remotely)
Active galactic nuclei (AGN) are among the most variable sources in the Universe, emitting energy across the entire electromagnetic spectrum. While AGN variability has been observed for decades, the mechanisms driving it remain poorly understood. The development of time-domain astronomy, enabled by missions like eROSITA, has led to the discovery of new transient phenomena, including changing-look AGN (CL-AGN). CL-AGN behaviour can occur due to several reasons, some of which are related to changes in the accretion flow, obscuration events, and tidal disruption events. While changing-look AGN have been studied in other wavelengths, the work that will be shown in this talk represents the first large-scale systematic X-ray study of CL-AGN candidates. Using eROSITA’s all-sky surveys provides a unique time-domain perspective with a cadence of six months. This talk will focus on the first two, with an overview of all five all-sky scans. The work is structured around two key objectives: improving the selection method for transient X-ray sources and conducting a statistical analysis of ignition (flux increase) and shut-down (flux decrease) events. Additionally, a robust multi-wavelength follow-up campaign, including observations with XMM-Newton, in combination with available multi-wavelength archival data, were used to characterize our X-ray selected sample.

Speaker: Sabina Bahic

17 Analysing HETDEX spectra from XMM detections

X-ray selection is still one of the best and least biased ways to find active galactic nuclei (AGN). But traditional selection methods can still miss faint and/or heavily obscured sources. In this master's thesis, I analyze X-ray AGN selection biases by integrating data from the HETDEX blind spectroscopic survey with XMM X-ray detections. I compare the latest XMM archival detection catalogs to previously published catalogs in the HETDEX field and use HETDEX spectroscopy to confirm Type 1 and Type 2 AGN candidates. I aim to (1) find out how many more real AGN are found with the latest XMM detection algorithms and (2) whether blind spectroscopic follow-up finds more obscured and Compton-thick AGN than traditional optical pre-selection methods. I will demonstrate the first results of this analysis and discuss future plans. This study will ultimately enhance the comprehension of AGN demographics and selection biases in X-ray surveys.

Speaker: Hema Priya Rajangam

18 A XRISM view of chemical enrichment in galaxy clusters

(remotely)

Speaker: François Mernier (IRAP)

10:55 Coffee break

Poster viewing

19 Poster viewing

20 The SRG/eROSITA upper limits of the Galactic Western hemisphere

We implemented the first half-sky SRG/eROSITA upper limit database to provide X-ray photometric data and flux upper limit to every position in the Western Galactic hemisphere. The eROSITA flux upper limits can be crucial for understanding the physical and statistical properties of variable objects, transients, and even large numbers of sources detected at wavelengths other than X-rays.
In this contribution, I will show how these eROSITA upper limits can complement data from the XMM-Newton catalogs and other X-ray astronomy missions (via HILIGT), providing decades-long light curves for selected sources. I will also describe the process of retrieving SRG/eROSITA upper limits, eROSITA data, X-ray aperture photometry procedure, upper limit calculation via a Bayesian approach, and the final data products.

Speaker: Dusán Tubín (Leibniz Institute for Astrophysics, AIP)

Science Advisory Group: Session 4

21 Quantifying the Intrinsic scatter in magnetic activity of cool stars using wide binaries

The magnetic activity of cool stars is connected to the stellar age. The activity-rotation relations combined with Gyrochronology give us the big picture of the evolution of cool star activity. However, how similar could coeval Gyr-old stars of the same metallicity and similar mass be in terms of magnetic activity? Little is understood about this intrinsic scatter of activity in cool stars. It is, however, an essential piece of information required to understand the variability in the stellar environment over gigayears of stellar evolution, including having implications on the evaporation of exoplanetary atmospheres.

In my talk, we investigate this scatter by using wide binaries. We conducted Bayesian catalogue matching between Gaia eDR3 wide binaries and the XMM-Newton DR14 catalogue to find serendipitous wide binaries in the XMM-Newton catalogue. We then use the X-ray luminosity $L_X$, an indicator of activity, to compare the similar mass components of the binary to find the intrinsic scatter of activity.

We find that the scatter of activity in partially and fully convective M-type binaries is much large than that seen in more massive cool stars of spectral types F, G, and K. This high scatter comes from M-type stars that are found to be in the saturated regime due to their very long spindown timescales. The intrinsic scatter in the wide binaries of all spectral types, however, is much smaller than that observed for randomly paired stars in the solar neighbourhood.

As the activity-rotation relations and gyrochronology continue to be calibrated for field stars, X-ray studies of wide binaries like these can help determine the degree of deviation from coeval behaviour in the solar neighbourhood without the need to determine precise ages.

Speaker: Desmond Dsouza (Leibniz Institute for Astrophysics Potsdam)

22 Serendipitous Searches for Isolated Neutron Stars in XMM-Newton Catalogues

(remotely)
We present a search for isolated neutron star (INS) candidates in the 4XMM-DR9 and 4XMM-DR12 catalogues, targeting sources with soft X-ray spectra and no optical/UV/IR counterparts. Bright unidentified sources were prioritised for follow-up with XMM-Newton, Chandra, Einstein Probe, radio observations with FAST, and optical follow-up with Gemini. These efforts have led to the identification of new INSs and provide constraints on their spatial distribution using Galactic extinction maps. Our results help characterise the faint, distant INS population and inform evolutionary models within the Milky Way.

Speaker: Adriana Mancini Pires (CLPS/CAS)

23 Characterising isolated neutron star candidates from eROSITA with XMM-Newton

The wide survey area and unprecedented sensitivity of the SRG/eROSITA All-Sky Survey allows to grow the still small population of isolated neutron stars (INSs) with detected thermal emission components. While a larger population of thermally emitting INSs promises unique insights into fundamental physics, neutron star properties, and proposed evolutionary links, a good characterisation of the newly selected candidates is required before they can be used in such studies. This makes follow-up observations with XMM-Newton a fundamental prerequisite. Here, we report on the results of an XMM-Newton/VLT large program that recently targeted seven eROSITA-selected INS candidates with the immediate goal to study their temporal and spectral emission properties, to establish their INS nature, and to set the basis for a larger flux-complete population of these enigmatic sources.

Speaker: Jan Kurpas (Leibniz-Institut für Astrophysik Potsdam (AIP))

24 X-ray Periodicities in the Gamma Cas Analogues

The mechanism for X-ray generation in the $\gamma$ Cas analogues, a small group of highly variable Oe/Be stars, has been a mystery for several decades. They are characterised by their hard X-ray spectra, often including strong Fe fluorescence lines, and X-ray luminosities in the gap between those seen in similar stars and the more luminous Be/X-ray Binaries. They have also been observed to be highly variable on a range of timescales, from seconds up to several years. Competing theories for the mechanism for X-ray production include magnetic interactions between the star and its decretion disk or accretion onto a compact companion.

We will present the results of a comprehensive review of medium-long term variability in a large sample of 88 XMM-Newton and 45 Chandra observations, using both Fourier- and time-domain techniques to search for periodicities. We present sources which appear to show periodicities across several observations, and outline how the periodicities in these sources can resolve the doubt over the nature of the X-ray emission from the $\gamma$ Cas analogues.

Speaker: Robbie Webbe (IRAP, Toulouse, France)

25 Wrap up

Speaker: Natalie Webb (IRAP)

13:00 Lunch break

Satellite events: Babelsberg tour (group 2)

Satellite events: Telegrafenberg tour (group 1)

SAS Working Group

26 Overview of SAS releases - SAS 23 and SAS 24 contents

Speaker: Richard Saxton (Telespazio UK for ESA (XMM-Newton SOC ESAC/ESA))

27 Status of code release

Speaker: Jari Kajava (Serco for ESA/ESAC)

28 SAS processing pipelines

(remotely)

Speaker: Jose Vicente Perea Calderon (ESAC)

29 EPIC-pn developments

(remotely)

Speaker: Michael Freyberg (MPE Garching, Germany)

30 Running SAS on Mac ARM chips

Speaker: Aitor Ibarra Ibaibarriaga (Telespazio UK for ESA (XMM-Newton SOC ESAC/ESA))

16:20 Coffee break

SAS Working Group

31 SAS development environment

Speaker: José Marcos

32 Source detection

Speaker: Dr Iris Traulsen (Leibniz-Institut für Astrophysik Potsdam (AIP))

33 ESAS updates and future plans

(remotely)

Speaker: Brendan Perry

34 SAS and Python

(remotely)

Speaker: Ryan Tanner

35 Wrap-up and good-bye

Speaker: Richard Saxton (Telespazio UK for ESA (XMM-Newton SOC ESAC/ESA))

Satellite events: Telegrafenberg tour (group 2)

Thursday, 19 March

Steering Group (Closed session)

12:30 Lunch option