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Galaxies with Milky Way-like stellar masses have a wide range of bulge and black hole masses; in turn, these correlate with other properties such as star formation history. While many processes may drive bulge formation, major and minor mergers are expected to play a crucial role. Stellar halos offer a novel and robust measurement of galactic merger history; cosmologically-motivated models predict that mergers with larger satellites produce more massive, higher metallicity stellar halos, reproducing the recently-observed stellar halo metallicity-mass relation. We quantify the relationship between stellar halo mass and bulge or black hole prominence using a sample of eighteen Milky Way-mass galaxies with newly-available measurements of (or limits on) stellar halo properties. There is an order of magnitude range in bulge mass, and two orders of magnitude in black hole mass, at a given stellar halo mass (or, equivalently, merger history). Galaxies with low mass bulges show a wide range of quiet merger histories, implying formation mechanisms that do not require intense merging activity. Galaxies with massive classical bulges and central black holes also show a wide range of merger histories. While three of these galaxies have massive stellar halos consistent with a merger origin, two do not - merging appears to have had little impact in making these two massive classical bulges. Such galaxies may be ideal laboratories to study massive bulge formation through pathways such as early gas-rich accretion, violent disk instabilities or misaligned infall of gas throughout cosmic time.
In the last decades several correlations between the mass of the central supermassive black hole (BH) and properties of the host galaxy - such as bulge luminosity and mass, central stellar velocity dispersion, Sersic index, spiral pitch angle etc. -
We present a study of 41 dwarf galaxies hosting active massive black holes (BHs) using Hubble Space Telescope observations. The host galaxies have stellar masses in the range of $M_star sim 10^{8.5}-10^{9.5}~M_odot$ and were selected to host active g
Previous studies of fueling black holes (BHs) in galactic nuclei have argued (on scales ~0.01-1000pc) accretion is dynamical with inflow rates $dot{M}simeta,M_{rm gas}/t_{rm dyn}$ in terms of gas mass $M_{rm gas}$, dynamical time $t_{rm dyn}$, and so
The dynamics of massive black holes (BHs) in galaxy mergers is a rich field of research that has seen much progress in recent years. In this contribution we briefly review the processes describing the journey of BHs during mergers, from the cosmic co
The mass estimator used to calculate black hole (BH) masses in broad-line active galactic nuclei (AGNs) relies on a virial coefficient (the $f$ factor) that is determined by comparing reverberation-mapped (RM) AGNs with measured bulge stellar velocit