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Title: ADAPTIVE OPTICS IMAGING OF QUASI-STELLAR OBJECTS WITH DOUBLE-PEAKED NARROW LINES: ARE THEY DUAL ACTIVE GALACTIC NUCLEI?

Abstract

Active galaxies hosting two accreting and merging supermassive black holes (SMBHs)-dual active galactic nuclei (AGNs)-are predicted by many current and popular models of black-hole-galaxy co-evolution. We present here the results of a program that has identified a set of probable dual AGN candidates based on near-infrared laser guide star adaptive optics imaging with the Keck II telescope. These candidates are selected from a complete sample of radio-quiet quasi-stellar objects (QSOs) drawn from the Sloan Digital Sky Survey (SDSS), which show double-peaked narrow AGN emission lines. Of the 12 AGNs imaged, we find 6 with double galaxy structure, of which four are in galaxy mergers. We measure the ionization of the two velocity components in the narrow AGN lines to test the hypothesis that both velocity components come from an active nucleus. The combination of a well-defined parent sample and high-quality imaging allows us to place constraints on the fraction of SDSS QSOs that host dual accreting black holes separated on kiloparsec scales: {approx}0.3%-0.65%. We derive from this fraction the time spent in a QSO phase during a typical merger and find a value that is much lower than estimates that arise from QSO space densities and galaxy merger statistics. Wemore » discuss possible reasons for this difference. Finally, we compare the SMBH mass distributions of single and dual AGNs and find little difference between the two within the limited statistics of our program, hinting that most SMBH growth happens in the later stages of a merger process.« less

Authors:
 [1]; ;  [2]; ;  [3];  [4]
  1. Max-Planck-Institute for Extraterrestrial Physics, Garching 85748 (Germany)
  2. Astronomy Department and UCO-Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)
  3. Astronomy Department, University of Texas, Austin, TX 78712 (United States)
  4. Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)
Publication Date:
OSTI Identifier:
21587505
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 739; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/739/1/44; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; GALAXIES; GALAXY NUCLEI; IONIZATION; MASS DISTRIBUTION; QUASARS; STATISTICS; VELOCITY; COSMIC RADIO SOURCES; DISTRIBUTION; MATHEMATICS; SPATIAL DISTRIBUTION

Citation Formats

Rosario, D. J., McGurk, R. C., Max, C. E., Shields, G. A., Smith, K. L., and Ammons, S. M., E-mail: rosario@mpe.mpg.de, E-mail: mcgurk@ucsc.edu, E-mail: max@ucolick.org, E-mail: shieldsga@mail.utexas.edu, E-mail: krista@mail.utexas.edu, E-mail: ammons@as.arizona.edu. ADAPTIVE OPTICS IMAGING OF QUASI-STELLAR OBJECTS WITH DOUBLE-PEAKED NARROW LINES: ARE THEY DUAL ACTIVE GALACTIC NUCLEI?. United States: N. p., 2011. Web. doi:10.1088/0004-637X/739/1/44; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Rosario, D. J., McGurk, R. C., Max, C. E., Shields, G. A., Smith, K. L., & Ammons, S. M., E-mail: rosario@mpe.mpg.de, E-mail: mcgurk@ucsc.edu, E-mail: max@ucolick.org, E-mail: shieldsga@mail.utexas.edu, E-mail: krista@mail.utexas.edu, E-mail: ammons@as.arizona.edu. ADAPTIVE OPTICS IMAGING OF QUASI-STELLAR OBJECTS WITH DOUBLE-PEAKED NARROW LINES: ARE THEY DUAL ACTIVE GALACTIC NUCLEI?. United States. doi:10.1088/0004-637X/739/1/44; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Rosario, D. J., McGurk, R. C., Max, C. E., Shields, G. A., Smith, K. L., and Ammons, S. M., E-mail: rosario@mpe.mpg.de, E-mail: mcgurk@ucsc.edu, E-mail: max@ucolick.org, E-mail: shieldsga@mail.utexas.edu, E-mail: krista@mail.utexas.edu, E-mail: ammons@as.arizona.edu. Tue . "ADAPTIVE OPTICS IMAGING OF QUASI-STELLAR OBJECTS WITH DOUBLE-PEAKED NARROW LINES: ARE THEY DUAL ACTIVE GALACTIC NUCLEI?". United States. doi:10.1088/0004-637X/739/1/44; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
@article{osti_21587505,
title = {ADAPTIVE OPTICS IMAGING OF QUASI-STELLAR OBJECTS WITH DOUBLE-PEAKED NARROW LINES: ARE THEY DUAL ACTIVE GALACTIC NUCLEI?},
author = {Rosario, D. J. and McGurk, R. C. and Max, C. E. and Shields, G. A. and Smith, K. L. and Ammons, S. M., E-mail: rosario@mpe.mpg.de, E-mail: mcgurk@ucsc.edu, E-mail: max@ucolick.org, E-mail: shieldsga@mail.utexas.edu, E-mail: krista@mail.utexas.edu, E-mail: ammons@as.arizona.edu},
abstractNote = {Active galaxies hosting two accreting and merging supermassive black holes (SMBHs)-dual active galactic nuclei (AGNs)-are predicted by many current and popular models of black-hole-galaxy co-evolution. We present here the results of a program that has identified a set of probable dual AGN candidates based on near-infrared laser guide star adaptive optics imaging with the Keck II telescope. These candidates are selected from a complete sample of radio-quiet quasi-stellar objects (QSOs) drawn from the Sloan Digital Sky Survey (SDSS), which show double-peaked narrow AGN emission lines. Of the 12 AGNs imaged, we find 6 with double galaxy structure, of which four are in galaxy mergers. We measure the ionization of the two velocity components in the narrow AGN lines to test the hypothesis that both velocity components come from an active nucleus. The combination of a well-defined parent sample and high-quality imaging allows us to place constraints on the fraction of SDSS QSOs that host dual accreting black holes separated on kiloparsec scales: {approx}0.3%-0.65%. We derive from this fraction the time spent in a QSO phase during a typical merger and find a value that is much lower than estimates that arise from QSO space densities and galaxy merger statistics. We discuss possible reasons for this difference. Finally, we compare the SMBH mass distributions of single and dual AGNs and find little difference between the two within the limited statistics of our program, hinting that most SMBH growth happens in the later stages of a merger process.},
doi = {10.1088/0004-637X/739/1/44; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 739,
place = {United States},
year = {2011},
month = {9}
}