A study of X-ray emission of galaxies hosting molecular outflows (MOX sample).

The AGN feedback plays a crucial role in black hole and host galaxy coevolution across cosmic time. However, the exact nature of the interaction between AGN outflows and the host galaxy at kpc scales is not clearly understood. With the advent of high spatial resolution infra-red (IR) and radio telescopes in the past couple of decades, we have made rapid progress in detecting and understanding the nature of molecular outflows, which are outflows detected at kpc scales and mostly manifest themsleves in the IR/sub-mm spectra as broadened emission and absorption lines. These molecular outflows may sometimes possess significant amount of kinetic and mass outflow rates, enough to impart feedback to the host galaxy gas and dust. Understanding the origin and driving mechanisms of these molecular outflows are therefore of paramount importance in order to decipher AGN and host galaxy interaction. We have carried out an extensive X-ray spectral analysis (Laha et al., ApJ 868:10, 2018) of a sample of 50 galaxies exhibiting molecular outflows (MOX sample) and characterized the X-ray properties of these galaxies to investigate the effect of the central AGN on their dynamical properties. We found two interesting results: 1. The AGN in the galaxies hosting molecular outflows (which are mostly infra-red bright ULIRGs and LIRGs) are not X-ray weak as were inferred using X-ray observations. Using the 12 micron AGN luminosity (from heated dust) as a proxy for the 2-10 keV AGN luminosity, we found that the central AGN are not X-ray weak and their hardness ratios are similar to that of the Seyferts. These galaxies are simply too obscured to be detected in X-rays, and in many cases obscured by Compton thick clouds. 2. The AGN plays a prominent role in driving the molecular outflows. However, we find that the starbursts are also influential in driving the molecular outflows. It still needs to be seen which one, AGN or starburst, plays the bigger role in driving these outflows.