Misaligned jets from Sgr A$^*$ and the origin of Fermi/eROSITA bubbles [HEAP]

http://arxiv.org/abs/2211.12967


One of the leading explanations for the origin of Fermi Bubbles is a past jet activity in the Galactic center supermassive black hole Sgr A$^$. The claimed jets are often assumed to be perpendicular to the Galactic plane. Motivated by the orientation of pc-scale nuclear stellar disk and gas streams, and a low inclination of the accretion disk around Sgr A$^$ inferred by the Event Horizon Telescope, we perform hydrodynamical simulations of nuclear jets significantly tilted relative to the Galactic rotation axis. The observed axisymmetry and hemisymmetry (north-south symmetry) of Fermi/eROSITA bubbles (FEBs) due to quasi-steady jets in Sgr A$^$ can be produced if the jet had a super-Eddington power ($\gtrsim 5\times 10^{44}$ erg s$^{-1}$) for a short time (jet active period $\lesssim 6$ kyr) for a reasonable jet opening angle ($\lesssim 10^\circ$). Such powerful explosions are, however, incompatible with the observed O VIII/O VII line ratio towards the bubbles, even after considering electron-proton temperature non-equilibrium. We argue that the only remaining options for producing FEBs are i) a low-luminosity ($\approx 10^{40.5-41}$ erg s$^{-1}$)) magnetically dominated jet or accretion wind from the Sgr A$^$, and ii) a SNe or TDE driven wind of a similar luminosity from the Galactic center.

Read this paper on arXiv…

K. Sarkar, S. Mondal, P. Sharma, et. al.
Thu, 24 Nov 22
69/71

Comments: 12 pages. Submitted to ApJ. Comments are welcome