2014ApJ...780...70L

We present an investigation of the scaling relations between supermassive black hole (SMBH) masses, M_•, and their host galaxies' K-band bulge (L_bul) and total (L_tot) luminosities. The wide-field WIRCam imager at the Canada-France-Hawaii-Telescope was used to obtain the deepest and highest resolution near-infrared images available for a sample of 35 galaxies with securely measured M_•, selected irrespective of Hubble type. For each galaxy, we derive bulge and total magnitudes using a two-dimensional image decomposition code that allows us to account, if necessary, for large- and small-scale disks, cores, bars, nuclei, rings, envelopes, and spiral arms. We find that the present-day M_•-L_bul and M_•-L_totrelations have consistent intrinsic scatter, suggesting that M_•correlates equally well with bulge and total luminosity of the host. Our analysis provides only mild evidence of a decreased scatter if the fit is restricted to elliptical galaxies. The log-slopes of the M_•-L_bul and M_•-L_totrelations are 0.75±0.10 and 0.92±0.14, respectively. However, while the slope of the M_•-L_bulrelation depends on the detail of the image decomposition, the characterization of M_•-L_totdoes not. Given the difficulties and ambiguities of decomposing galaxy images into separate components, our results indicate that L_totis more suitable as a tracer of SMBH mass than L_bul, and that the M_•-L_totrelation should be used when studying the co-evolution of SMBHs and galaxies.