A correlation between galaxy light concentration and supermassive black hole mass

We present evidence for a strong correlation between the concentration of bulges and the mass of their central supermassive black hole (M-bh)-more concentrated bulges have more massive black holes. Using C-rc(1/3) from Trujillo, Graham, & Caon as a measure of bulge concentration, we find that log (M-bh/M-.) = 6.81 (+/-0.95)C-re(1/3) + 5.03 +/- 0.41. This correlation is shown to be marginally stronger (Spearman's r(s) = 0.91) than the relationship between the logarithm of the stellar velocity dispersion and log M-bh (Spearman's r(s) = 0.86) and has comparable or less scatter (0.31 dex in log M-bh, which decreases to 0.19 dex when we use only those galaxies whose supermassive black hole radii of influence are resolved and we remove one well-understood outlying data point).