M31* and its circumnuclear environment

Understand

We present a multiwavelength investigation of the circumnuclear environment of M31.

• Based on Chandra/ACIS data, we tightly constrain the X-ray luminosity of M31*, the central supermassive black hole of the galaxy, to be L (0.3-7 keV)<= 1.2x10^{36}erg/s, approximately 10^{-10} of the Eddington luminosity.
• From the diffuse X-ray emission, we characterize the circumnuclear hot gas with a temperature of ~0.3 keV and a density of ~0.1 cm^{-3}.
• In the absence of an active SMBH and recent star formation, the most likely heating source for the hot gas is Type Ia SNe.