eROSITA - Science and Data Analysis School

18 Nov 2024, 09:00 → 22 Nov 2024, 17:00 Europe/Berlin

New Seminar Room (MPE)

Vadim Burwitz (MPE)

This eROSITA - Science and Data Analysis School is organized by the AHEAD2020 project in the European Union framework program Horizons 2020. 

This school is aimed at PhD Students and early career Postdocs who are already or intending to analyze eROSITA data.

MPE is hosting this school. The experts at MPE, who have developed, built, and run eROSITA, will give an in-depth introduction to how the X-ray telescope works, is calibrated, and how the data should be analyzed using the pipelines developed at MPE. For this purpose, experts in different scientific fields will, in the mornings, introduce their topic of study in detail. These introductions will be followed up with hands-on afternoon data analysis sessions.  

Monday, 18 November

09:00 → 09:15 Welcome

Speaker: Dr Vadim Burwitz (MPE)

09:15 → 09:45 eROSITA Overview

I will present a brief overview of the eROSITA science program, with particular emphasis on the all-sky survey, and describe how the eROSITA X-ray data can be used to open up new discovery spaces across several areas of high-energy astrophysics.

Speaker: Dr Andrea Merloni (MPE)

09:45 → 10:25 How eROSITA came to be !

Speaker: Dr Peter Predehl (MPE)

10:25 → 10:50 Coffee

10:50 → 11:20 eROSITA Cameras

The seven eROSITA cameras are a further development of the PN-camera on ESA's XMM-Newton satellite. The eROSITA camera concept and design are explained, and the development is described. Its key component is the silicon PN-CCD detector, which was custom-developed for the eROSITA project. The most important scientific parameters are the energy, spatial, and time resolution, as well as the quantum efficiency and long-term stability. I describe the measured properties and performance of the cameras and discuss their advantages and disadvantages. Finally, expected and unexpected effects during camera operation in space are presented, and I conclude with a recent application of the eROSITA detector for the Einstein Probe satellite.

Speaker: Dr Norbert Meidinger (MPE)

11:20 → 12:20 eROSITA Optics

Speaker: Dr Peter Friedrich (MPE)

12:20 → 13:45 Lunch

13:45 → 15:15 eROSITA Calibration

The power of eROSITA (extended ROentgen Survey with an Imaging Telescope Array), the soft X-ray instrument on the Russian–German Spectrum–Roentgen–Gamma (SRG) mission, is high sensitivity at high spectral, spatial, and temporal resolution over a large field of view. This is achieved by combining 7 coaligned X-ray telescope modules, each composed of 54 paraboloid/hyperboloid mirror shells in a Wolter–I geometry, to focus the X–rays through optical blocking filters onto PN-CCDs with a total of 1 million pixels, providing a spectral resolution of 60 – 160 eV FWHM over an energy range 0.2 – 8 keV and a 1-degree field of view at a time resolution of 50 ms. In order to make full scientific use of the unique capabilities of eROSITA, it is essential to know quantitatively how the instrument modifies the incident signal. Therefore, all of its components have to be calibrated. I will report on the extensive and often challenging calibration activities performed on ground and in space.

Speaker: Dr Konrad Dennerl (MPE)

15:15 → 15:45 Coffee

15:45 → 16:45 eROSITA Operations / Data Analysis

The eROSITA ground operations comprise the areas of mission planning, telescope operation, and data reception, the operation of the data processing pipeline, and the creation of tools for data access and interactive data analysis. All these activities take place at and are the responsibility of MPE.
Since its launch, eROSITA spent almost 1,000 days in nominal operations. During this time, the eROSITA operations team had a daily basis interaction in real-time with Mission Control in Moscow to carry out routine, maintenance, and contingency operations, as well as the downlink of the observed data.

The eROSITA data processing pipeline consists of modules for data ingestion, event calibration, exposure calculation, source detection, and the creation of high-level source-specific data products. It is operated at MPE, and the data products are released to the collaboration members and the public. A subset of the software tasks comprising the data analysis pipeline also functions as interactive data analysis tools for scientists who are interested in eROSITA data. These can be grouped into tasks for X-ray event calibration, selection and binning, exposure, background and sensitivity map creation, and source detection.

In this talk, I will show how the daily operations of eROSITA were carried out during nominal operations. A tour of the eROSITA control room will be possible. Furthermore, I will guide you through the process of how the observed X-ray photons are transformed into FITS files that you can analyze and use for your research.

Speaker: Dr Miriam Ramos-Ceja (MPE)

Tuesday, 19 November

09:00 → 10:30 White Dwarfs

Speaker: Dr Susanne Friedrich (MPE)

10:30 → 11:00 Coffee

11:00 → 12:30 Diffuse Emission

Speaker: Dr Gabriele Ponti (MPE)

12:30 → 14:00 Lunch

14:00 → 17:00 Hands-on Session White Dwarfs / Diffuse Emission

Speakers: Dr Susanne Friedrich (MPE), Dr Gabriele Ponti (MPE)

Wednesday, 20 November

09:00 → 10:30 Overview Clusters of Galaxies

A significant milestone in X-ray survey science was achieved with the successful launch of eROSITA in July 2019. The German-built eROSITA X-ray telescope, on board the Russian-German Spectrum-RG (SRG) mission, operates within the 0.2-8 keV range and has produced the largest ICM-detected catalogs of galaxy clusters and groups through its All-Sky Surveys. The first eROSITA all-sky survey, with over 10,000 confirmed clusters, is pivotal in cluster astrophysics. I will give an overview of the physical properties of clusters of galaxies and galaxy groups and present rich cluster science eROSITA initiated.

Speaker: Dr Esra Bulbul (MPE)

10:30 → 11:00 Coffee

11:00 → 12:30 Clusters: Data analysis

The primary mission of eROSITA is to detect clusters of galaxies in order to measure cosmological parameters. In order to build a cosmological model, we also need well-characterized X-ray mass measurements. Therefore, detecting clusters and measuring their properties is therefore a very important aspect of eROSITA data analysis. We will describe how clusters are detected in the eROSITA sky survey by the standard detection pipeline. Measuring the properties of clusters requires a combination of imaging and spectral analyses. We will discuss the MBProj2D (Multi-Band Projector in 2D), a Python package that simultaneously models clusters in multiple energy bands to measure radial profiles of their physical properties. We will also discuss the accurate spectral fitting of clusters.

Speaker: Dr Jeremy Sanders (MPE)

12:30 → 14:00 Lunch

14:00 → 17:00 Hands-on Session Clusters of Galaxies

We will guide the attendees through measuring the properties of clusters of galaxies. The session will focus on fitting images of clusters of galaxies with MBProj2D to obtain profiles of their physical properties, such as density and gas mass. This will include extracting images, setting up a model, fitting it, and interpreting the results. We will also cover the extraction and fitting of spectra from clusters.

Speakers: Dr Esra Bulbul (MPE), Dr Jeremy Sanders (MPE)

Thursday, 21 November

09:00 → 10:30 Overview AGN

Active galactic nuclei dominate the source population of eROSITA, with over a million point sources. In the extreme gravitational environment of black holes, gas accretion is accompanied by emission across the wavelength spectrum. eROSITA studies range from understanding this central engine, including the hot plasma emitting X-rays, the special viewpoint of blazars, transients such as sudden turn-on caused by the tidal disruption of stars, and characterizing the galactic nuclei and their cosmic web environment conducive to triggering black hole growth.

Speaker: Dr Johannes Buchner (MPE)

10:30 → 11:00 Coffee

11:00 → 12:30 AGN: Data Analysis

Speaker: Dr Johannes Buchner (MPE)

12:30 → 14:00 Lunch

14:00 → 17:00 Hands-on Session AGNs

Speaker: Dr Johannes Buchner (MPE)

Friday, 22 November

09:00 → 10:30 Multiwavelength identification of counterparts to X-ray sources - overview

During this session, we will discuss all the facts that may undermine the correct identification of the multiwavelength counterparts to X-ray sources, such as X-ray catalog properties, ancillary data characteristics, and type of X-ray sources (Galactic, extragalactic).

Speaker: Dr Mara Salvato (MPE)

10:30 → 11:00 Coffee

11:00 → 12:30 Multiwavelength identification of counterparts to X-ray sources - Data Analysis

Speaker: Dr Mara Salvato (MPE)

12:30 → 14:00 Lunch

14:00 → 17:00 Hands-on Session Multiwavelength identification of counterparts to X-ray sources

We will also have hands-on experience using NWAY (Salvato et al. 2018), a Bayesian algorithm that can provide a reliable association between catalogs and account for externally computed priors.

Speaker: Dr Mara Salvato (MPE)