Black Hole Growth by Accretion

Smita Mathur (The Ohio State University)

Normal galaxies and some broad line Seyfert galaxies follow a tight correlation between the black hole mass and the bulge mass. Is the BH mass to bulge mass ratio constant over time, and is it the same for all galaxies? There is growing evidence that such is not the case. At high redshifts, it appears that the BHs grow faster than the spheroids. At low redshifts, however, BHs seem to grow in well formed bulges. I'll discuss our results showing that the NLS1 galaxies lie below the M-sigma relation, implying that their BHs are still growing in mass. It shows that accretion plays a major role in BH growth. Even though optically selected NLS1s appear to be a mixed bag, highly accreting NLS1s are still growing in their BH mass. These observations challenge many theories attempting to explain the M-sigma relation.

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