Abstract Details
| Name: SANANDA RAYCHAUDHURI Affiliation: BOSE INSTITUTE, KOLKATA Conference ID: ASI2018_1564 Title : Accretion in five component elliptical galaxy : Multitransonicity, shocks and implications on AGN feedback Authors and Co-Authors : Shubhrangshu Ghosh,Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai, Parthasarathi Joarder, CAPSS,Bose Institute, Kolkata Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : Isolated massive ellipticals, or that are present at the centre of cool-core clusters, are widely argued to be powered by hot gas accretion directly from their surrounding hot x-ray emitting phase. This leads to a giant Bondi-type spherical or quasi-spherical accretion flow onto the central SMBH, even exceeding hundreds of kpc length-scale, particularly, in context of flows from ICM. We incorporate the entire galactic contribution to the potential considering a five component elliptical galaxy (SMBH + stellar + dark matter + hot gas + Lambda). The adiabatic spherical flow displays a remarkable behaviour, with the appearance of multi-criticality in the flow, indicating significant departure from the classical Bondi solution. More notably, corresponding to moderate to higher values of mass-to-light ratios, we obtain possible Rankine-Hugoniot shocks in the corresponding wind flows, with the global flow topology resembling the x-alpha -type trajectories of advection accretion flows. Galactic contribution to the potential enhances the Bondi accretion rate. Our study reveals that there is a strict lower limit of ambient temperature below which no Bondi-type accretion can occur; which is as high as 9X10^6 K for flows from hot ISM-phase, indicating that for isolated ellipticals, the hot phase tightly regulates the fuelling of host nucleus, enabling a tight feedback to occur between them. |