March 2016

bh_bulge_merger3.001

Where are merger triggered AGN located on the BH mass stellar mass relation?

For this plot I looked for mergers up to 1Gyr back in time for all AGN at redshift z=2. The plot shows the BH mass versus the stellar mass for AGN, where no merger (blue), a minor merger (magenta) or a major merger (yellow) occurred. The data is taken from two different simulations of the Magneticum Pathfinder Simulations, a small box with a very high resolution (68Mpc/uhr) and a much larger box with a lower resolution (500Mpc/hr).  For comparison, the black line shows the observed relation from McConnell & Ma (2013). In contrast to AGN without a merger (note that blue dots are over-plotted by magenta and yellow dots), minor and major mergers mostly lie below that relation. This indicates that during a merger, the stellar mass begins to grow earlier than the BH mass.