Astrophys. J., Suppl. Ser., 208, 24 (2013/October-0)
The Spitzer mid-infrared active galactic nucleus survey. I. Optical and near-infrared spectroscopy of obscured candidates and normal active galactic nuclei selected in the mid-infrared.
LACY M., RIDGWAY S.E., GATES E.L., NIELSEN D.M., PETRIC A.O., SAJINA A., URRUTIA T., COX DREWS S., HARRISON C., SEYMOUR N. and STORRIE-LOMBARDI L.J.
Abstract (from CDS):
We present the results of a program of optical and near-infrared spectroscopic follow-up of candidate active galactic nuclei (AGNs) selected in the mid-infrared. This survey selects both normal and obscured AGNs closely matched in luminosity across a wide range, from Seyfert galaxies with bolometric luminosities L bol∼ 1010 L☉ to highly luminous quasars (Lbol∼ 1014 L☉), all with redshifts ranging from 0 to 4.3. Samples of candidate AGNs were selected with mid-infrared color cuts at several different 24 µm flux density limits to ensure a range of luminosities at a given redshift. The survey consists of 786 candidate AGNs and quasars, of which 672 have spectroscopic redshifts and classifications. Of these, 137 (20%) are type 1 AGNs with blue continua, 294 (44%) are type 2 objects with extinctions AV ≳ 5 toward their AGNs, 96 (14%) are AGNs with lower extinctions (AV ∼ 1), and 145 (22%) have redshifts, but no clear signs of AGN activity in their spectra. Of the survey objects 50% have Lbol> 1012 L☉, in the quasar regime. We present composite spectra for type 2 quasars and objects with no signs of AGN activity in their spectra. We also discuss the mid-infrared–emission-line luminosity correlation and present the results of cross correlations with serendipitous X-ray and radio sources. The results show that: (1) obscured objects dominate the overall AGN population, (2) mid-infrared selected AGN candidates exist which lack AGN signatures in their optical spectra but have AGN-like X-ray or radio counterparts, and (3) X-ray and optical classifications of obscured and unobscured AGNs often differ.
galaxies: Seyfert - galaxies: starburst - infrared: galaxies - quasars: general
VizieR on-line data:
<Available at CDS (J/ApJS/208/24): table1.dat table2.dat table3.dat table5.dat refs.dat>
Table 3 : XFLS171336.314+600759.26 is SDSS J171336.29+600800.4 in SIMBAD; XFLS171550.522+593548.66 is 2MASX J17155047+5935486 in SIMBAD.
View the references in ADS