Point source contribution to the Diffuse X-ray Background below 1 keV and its effect on our understanding of the circum-galactic medium

We studied the spectral signatures of different components of the Diffuse X-ray Background (DXB), including Local Hot Bubble (LHB), Solar Wind Charge eXchange (SWCX), Galactic Halo, and typically unresolved point sources (Galaxies and AGN), in the direction of the Chandra Deep Field South (CDFS) using the 4 Ms XMM-Newton survey and Chandra identified point sources.In this paper we preset our results showing how the different components contribute to the DXB below 1 keV. In particular, we have found that a significant fraction of the emission at ¾ keV, which is typically associated with Galactic Halo (GH) and Circum-galactic medium (CGM) is, in fact, due to emission from typically unresolved Galaxies. We’ll discuss the effect that this has on our understanding of GH and CGM, and to our understanding of the missing CGM baryons.