Astrophys. J., 755, 167 (2012/August-3)
A uniformly selected sample of low-mass black holes in Seyfert 1 galaxies.
DONG X.-B., HO L.C., YUAN W., WANG T.-G., FAN X., ZHOU H. and JIANG N.
Abstract (from CDS):
We have conducted a systematic search of low-mass black holes (BHs) in active galactic nuclei (AGNs) with broad Hα emission lines, aiming at building a homogeneous sample that is more complete than previous ones for fainter, less highly accreting sources. For this purpose, we developed a set of elaborate, automated selection procedures and applied it uniformly to the Fourth Data Release of the Sloan Digital Sky Survey. Special attention is given to AGN-galaxy spectral decomposition and emission-line deblending. We define a sample of 309 type 1 AGNs with BH masses in the range 8x104-2 x106 M☉(with a median of 1.2x106 M☉), using the virial mass estimator based on the broad Hα line. About half of our sample of low-mass BHs differs from that of Greene & Ho, with 61 of them discovered here for the first time. Our new sample picks up more AGNs with low accretion rates: the Eddington ratios of the present sample range from ≲ 0.01 to ∼1, with 30% below 0.1. This suggests that a significant fraction of low-mass BHs in the local universe are accreting at low rates. The host galaxies of the low-mass BHs have luminosities similar to those of L* field galaxies, optical colors of Sbc spirals, and stellar spectral features consistent with a continuous star formation history with a mean stellar age of less than 1 Gyr.
galaxies: active - galaxies: nuclei - galaxies: Seyfert
VizieR on-line data:
<Available at CDS (J/ApJ/755/167): table1.dat table2.dat table3.dat>
View the reference in ADS
To bookmark this query, right click on this link: simbad:2012ApJ...755..167D and select 'bookmark this link' or equivalent in the popup menu