Institut für Astronomie & Astrophysik

Studies of SNRs with eROSITA and more

Miltiadis Michalilidis (IAAT) Tübingen, November 20, 2023

Since the end of 2019, the seven eROSITA telescopes onboard the Russian-German Spectrum-Roentgen-Gamma satellite (SRG) are used to perform an All-Sky X-ray survey in the soft to medium X-ray band (0.2-8.0 keV). Given eROSITA’s CCD-type sensitivity and energy coverage well beyond the ROSAT XRT’s upper energy range (2 keV), eRASS is ideally suited to discover and investigate the X-ray emission from a variety of astrophysical objects for example supernova remnants (SNRs), including those which are highly absorbed and/or exhibit non-thermal spectral components.

The apparent size of evolved Galactic SNRs depends on their distance.  
In close proximity to Earth (hundreds of parsecs), they can reach degree-scale sizes. Current imaging X-ray instruments (e.g., XMM-Newton, Chandra) have a limited field of view (FoV), making them difficult to study in X-rays. In many cases, imaging survey data is the only option. In this respect, eROSITA (a wide-angle grazing-incident X-ray telescope providing All-Sky Survey data) offers a unique opportunity to study such objects with unprecedented sensitivity.

In this talk, I am going to walk you through the eROSITA view (but not only) of SNRs. I will showcase how SNR evolve, what we can learn from studying the latter objects, and how they contribute to the Milky Way as we observe it today. I will further outline how X-ray Astronomy fits in, why eROSITA is an ideal instrument for shortening the gap between the observed SNR in X-rays and the total number of known Galactic SNR, and I will highlight three individual SNR detected in X-rays with eROSITA data for the first time. Lastly, I will explain how we can learn about those objects' physical processes by studying them across the entire electromagnetic spectrum.