No evidence of galaxy-scale hot outflows in two nearby AGN!

Tuesday, July 3, 2018

Based on deep Chandra X-ray observations of two nearby AGN (HE0227-0913 and HE0351+0240), M. Powell et al. reported no evidence of galaxy-wide hot gas outflows. After careful analysis of the Chandra PSF to deal with the bright type 1 AGN core, no significant extended emission could be detected. This is a surprising result since current theoretical models predict rather bright X-ray emission from hot gas outflows on kpc-scales powered by the AGN.

This shows that the prediced outflows are not necessarily ubiquitos in AGN host galaxies. Either the multi-phase gas composition is different than predicited, the AGN is too young to show outflows on large scales, or the AGN is actually not capable of diriving a powerful outflow. Of course, with two objects we cannot systematically explore these effects, but these X-ray observations needed are expensive were done here as a pilot study. We expect that the CARS team is going to obtain additional Chandra observations in the future.


Chandra X-ray images of HE0227-0913 and HE0351+0240 together with their matched simulated PSFs. Below is the X-ray spectrum extracted from the read-out strike that is modelled with a single power-law model.