Detecting Missing Baryons around the Milky Way and External Galaxies
Abstract
Gas at the virial temperature of the Milky Way, about 2E6 K has been detected in O VII and O VIII with XMM and Chandra. With proper design, Athena will be able to detect many more of these lines, including both the O VII Ka and Kb line, which are important diagnostics of opacity. We have calculated the line strengths and profiles for various Milky Way sight lines and show that these observations will determine the Doppler b parameter and improve the metallicity determinations, with likely increases from the current value of 0.3 solar. If hot halos similar to the Milky Way exist around other spiral galaxies, we show that Athena will be able to detect them to projected distances of about 100 kpc.
- Publication:
-
Exploring the Hot and Energetic Universe: The first scientific conference dedicated to the Athena X-ray observatory
- Pub Date:
- September 2015
- Bibcode:
- 2015eheu.conf...15B