KILOPARSEC-SCALE SPATIAL OFFSETS IN DOUBLE-PEAKED NARROW-LINE ACTIVE GALACTIC NUCLEI. I. MARKERS FOR SELECTION OF COMPELLING DUAL ACTIVE GALACTIC NUCLEUS CANDIDATES

Journal Article · Sun Jul 01 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/753/1/42· OSTI ID:22036914

Comerford, Julia M ^[1]; Gerke, Brian F ^[2]; Stern, Daniel ^[3]; Cooper, Michael C ^[4]; Weiner, Benjamin J ^[5]; Newman, Jeffrey A ^[6]; Madsen, Kristin ^[7]; Barrows, R Scott ^[8]

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1. Astronomy Department, University of Texas at Austin, Austin, TX 78712 (United States)
2. Kavli Institute for Particle Astrophysics and Cosmology, M/S 29, Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, CA 94725 (United States)
3. Jet Propulsion Laboratory, California Institute of Technology, MS 169-221, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)
4. Center for Galaxy Evolution, Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697 (United States)
5. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
6. Department of Physics and Astronomy, Pittsburgh Particle Physics, Astrophysics, and Cosmology Center, University of Pittsburgh, Pittsburgh, PA 15260 (United States)
7. Space Radiation Laboratory, California Institute of Technology, MS 105-24, Pasadena, CA 91125 (United States)
8. Arkansas Center for Space and Planetary Sciences, University of Arkansas, Fayetteville, AR 72701 (United States)

Merger-remnant galaxies with kiloparsec (kpc) scale separation dual active galactic nuclei (AGNs) should be widespread as a consequence of galaxy mergers and triggered gas accretion onto supermassive black holes, yet very few dual AGNs have been observed. Galaxies with double-peaked narrow AGN emission lines in the Sloan Digital Sky Survey (SDSS) are plausible dual AGN candidates, but their double-peaked profiles could also be the result of gas kinematics or AGN-driven outflows and jets on small or large scales. To help distinguish between these scenarios, we have obtained spatial profiles of the AGN emission via follow-up long-slit spectroscopy of 81 double-peaked narrow-line AGNs in SDSS at 0.03 {<=} z {<=} 0.36 using Lick, Palomar, and MMT Observatories. We find that all 81 systems exhibit double AGN emission components with {approx}kpc projected spatial separations on the sky (0.2 h{sup -1}{sub 70} kpc <{Delta}x < 5.5 h{sup -1}{sub 70} kpc; median {Delta}x = 1.1 h{sup -1}{sub 70} kpc), which suggests that they are produced by kiloparsec-scale dual AGNs or kiloparsec-scale outflows, jets, or rotating gaseous disks. Further, the objects split into two subpopulations based on the spatial extent of the double emission components and the correlation between projected spatial separations and line-of-sight velocity separations. These results suggest that the subsample (58{sup +5}{sub -6}%) of the objects with spatially compact emission components may be preferentially produced by dual AGNs, while the subsample (42{sup +6}{sub -5}%) with spatially extended emission components may be preferentially produced by AGN outflows. We also find that for 32{sup +8}{sub -6}% of the sample the two AGN emission components are preferentially aligned with the host galaxy major axis, as expected for dual AGNs orbiting in the host galaxy potential. Our results both narrow the list of possible physical mechanisms producing the double AGN components, and suggest several observational criteria for selecting the most promising dual AGN candidates from the full sample of double-peaked narrow-line AGNs. Using these criteria, we determine the 17 most compelling dual AGN candidates in our sample.

• OSTI ID: 22036914
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 753; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION SPECTROSCOPY
ASTRONOMY
ASTROPHYSICS
BLACK HOLES
CORRELATIONS
EMISSION SPECTROSCOPY
GALAXIES
GALAXY NUCLEI
JETS
PHOTON EMISSION