DOES THE INTERMEDIATE-MASS BLACK HOLE IN LEDA 87300 (RGG 118) FOLLOW THE NEAR-QUADRATIC Mbh-Mspheroid RELATION?

The mass scaling relation between supermassive black holes and their host spheroids has previously been described by a quadratic or steeper relation at low masses (10(5) < M-bh/M-circle dot less than or similar to 10(7)). How this extends into the realm of intermediate-mass black holes (10(2) < M-bh/M-circle dot < 10(5)) is not yet clear, although for the barred Sm galaxy LEDA 87300, Baldassare et al. recently reported a nominal virial mass of M-bh = 5 x 10(4) M-circle dot residing in a "spheroid" of stellar mass equal to 6.3 x 10(8) M-circle dot. We point out, for the first time, that LEDA. 87300 therefore appears to reside on the near-quadratic M-bh-M-sph,M-* relation. However, Baldassare et al. modeled the bulge and bar as the single spheroidal component of this galaxy. Here we perform a 3-component bulge+bar+disk decomposition and find a bulge luminosity which is 7.7 times fainter than the published "bulge" luminosity. After correcting for dust, we find that M-bulge = 0.9 x 10(8) M-circle dot and M-bulge/M-disk = 0.04-which is now in accord with ratios typically found in Scd-Sm galaxies. We go on to discuss slight revisions to the stellar velocity dispersion (40 +/- 11 km s(-1)) and black hole mass (M-bh = 2.9(-2.3)(+6.47) x 10(4) f(2.3) M-circle dot) and show that LEDA. 87300 remains consistent with the M-bh-sigma relation, and also the near-quadratic M-bh-M-sph,M-* relation when using the reduced bulge mass. LEDA. 87300 therefore offers the first support for the rapid but regulated (near-quadratic) growth of black holes, relative to their host bulge/spheroid, extending into the domain of intermediate-mass black holes.