A Reverberation-Based Black Hole Mass for MCG-06-30-15

Abstract

We present the results of a reverberation campaign targeting MGC-06-30-15. Spectrophotometric monitoring and broad-band photometric monitoring over the course of 4 months in the spring of 2012 allowed a determination of a time delay in the broad H${\hat{I}}^2$ emission line of $\ddot{I}„=5.3\pm 1.8$ days in the rest frame of the AGN. Combined with the width of the variable portion of the emission line, we determine a black hole mass of $M_{\mathrm{BH}}=(1.6\pm 0.4)\times 10^6$ M${}_{\odot }$. Both the H${\hat{I}}^2$ time delay and the black hole mass are in good agreement with expectations from the $R_{\mathrm{BLR}}$-$L$ and $M_{\mathrm{BH}}-\ddot{I}{ƒ}_{\star }$ relationships for other reverberation-mapped AGNs. The H${\hat{I}}^2$ time delay is also in good agreement with the relationship between H${\hat{I}}^2$ and broad-band near-IR delays, in which the effective BLR size is $\sim 4-5$ times smaller than the inner edge of the dust torus. Additionally, the reverberation-based mass is in good agreement with estimates from the X-ray power spectral density break scaling relationship, and with constraints based on stellar kinematics derived from integral field spectroscopy of the inner $\sim 0.5$ kpc of the galaxy.

13 pages, 9 figures, 4 tables, accepted for publication in ApJ