ONLINE-COLLOQUIUM: Nandini Sahu (Swinburne University)
Wann: Mi, 15.12.2021, 14:00 Uhr
Morphology-dependent Black Hole Mass Scaling Relations
For decades, astronomers have been investigating the connection between supermassive black holes (SMBH) and their host galaxies. I will talk about my work based on the largest-yet sample of galaxies with dynamically measured central SMBH masses, which adds another step towards understanding black hole (BH) scaling relations. We measured the host galaxy properties using state-of-the-art two-dimensional isophotal modeling and the multi-component photometric-decomposition, incorporating the kinematic evidence for the presence of stellar disks.
These decompositions allowed us to accurately estimate the galactic spheroid properties and reliably identify the galaxy morphologies. We investigated the BH mass scaling relations for various sub-morphological classes of galaxies, i.e., galaxies with and without a disk, early-type versus late-type galaxies, barred versus non-barred galaxies, and Sersic (gas-abundant accretion/wet merger) versus core-Sersic (depleted-core, dry merger) galaxies.
Consequently, we have discovered significantly modified correlations of BH mass with galaxy properties, e.g., the spheroid stellar mass, total galaxy stellar mass, central stellar velocity dispersion, bulge central light concentration, bulge size, and the bulge projected and internal stellar mass density. The final scaling relations are dependent on galaxy morphology, fundamentally linked with galaxy formation and evolutionary paths. These relations provide consistent predictions for the very recent directly measured BHs. The morphological dependence of BH scaling relations poses ramifications for the virial factor used in the reverberation mapping technique and offers tests for simulations and theories for BH-galaxy co-evolution. These relations can be used to estimate the BH merger time scales, morphology-aware BH mass function, and improved characteristic strain model for the ground- and space-based detection of long-wavelength gravitational waves generated by merging SMBHs.