Improving Calibration of the MBH-σ* Relation for AGN with the BRAVE Program
Research output: Working paper › Research › peer-review
The MBH - σ* relation for AGN, which relates the mass of the central supermassive black hole (MBH) to the bulge stellar velocity dispersion (σ*) of the host galaxy, is a powerful tool for studying the evolution of structure across cosmic time. Accurate calibration of this relation is essential, and much effort has been put into improving MBH determinations with this in mind. However calibration remains difficult because many nearby AGN with secure MBH determinations are hosted by late-type galaxies, with significant kinematic substructure such as bars, disks and rings. Kinematic substructure is known to contaminate and bias σ* determinations from long-slit and single aperture spectroscopy, ultimately limiting the utility of the MBH - σ* relation, and hampering efforts to investigate morphological dependencies. Integral-field spectroscopy (IFS) can be used to map the two dimensional kinematics, providing a method for measuring σ* absent some of the biases inherent in other methods, and giving a more complete picture of the spatial variations in the dynamics. We present the first set of results from the BRAVE program, the long-term goal of which is to use IFS to more accurately determine σ* for the calibrating sample of reverberation-mapped AGN. We present IFS kinematic maps for the sample of galaxies we have so far observed, which show clearly how spatial variation can impact σ* determinations from long-slit spectroscopy. We present a new fit to the MBH - σ* relation for the sample of 16 reverberation-mapped AGN for which we currently have σ* determinations from IFS, as well as a new determination of the virial scaling factor, f, for use with reverberation-mapping.
|Publisher||American Astronomical Society, AAS Meeting #229|
|Publication status||Published - 1 Jan 2017|