Testing the Correlation between Spiral Arm Pitch Angle and Central Black Hole Mass

Douglas W. Shields, J. Adam Hughes, Scott R. Barrows, Ben Davis, Daniel Kennefick, Julia Kennefick, William Ring, Marc Seigar, Daniel J. Whalen, Volker Bromm, Naoki Yoshida
In order to address the "cosmic downsizing problem," or the underpopulation of highly massive quasars in the current epoch, the Arkansas Galaxy Evolution Survey (AGES) is exploring a correlation, the M-P relation, between the pitch angle of a galaxy's spiral arms and the mass of its central supermassive black hole (SMBH). The goal is to generate a census of SMBH masses using only images, without relying on spectra. This study presents preliminary results testing the M-P relation by comparing
more » ... masses of a sample of active spiral galaxies as calculated by the pitch angle method with those calculated by the mass scaling relationship. Additionally, we present the null correlation between the pitch angle of spiral galaxies and redshift. The data set includes 225 galaxies from the GOODS North and South fields with redshifts out to z ~ 1.2. There does not appear to be any dependence of pitch angle on redshift. Consequently, if the relationship between pitch angle and SMBH mass has not evolved since z ~ 1.2, then the mean mass of SMBH has also remained constant. If, on the other hand, the relationship has evolved, then the mean mass has evolved inversely with the relationship. This conclusion is subject to further studies on possible selection effects.
doi:10.1063/1.3518878 fatcat:auxz3paynvbvtfjrzlzmoggcqq