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Title: CHANDRA DISCOVERY OF A BINARY ACTIVE GALACTIC NUCLEUS IN Mrk 739

Abstract

We have discovered a binary active galactic nucleus (AGN) in the galaxy Mrk 739 using Chandra and Swift BAT. We find two luminous (L{sub 2-10 keV} = 1.1 x 10{sup 43} and 1.0 x 10{sup 42} erg s{sup -1}), unresolved nuclei with a projected separation of 3.4 kpc (5.''8 {+-} 0.''1) coincident with two bulge components in the optical image. The western X-ray source (Mrk 739W) is highly variable (x 2.5) during the 4 hr Chandra observation and has a very hard spectrum consistent with an AGN. While the eastern component was already known to be an AGN based on the presence of broad optical recombination lines, Mrk 739W shows no evidence of being an AGN in optical, UV, and radio observations, suggesting the critical importance of high spatial resolution hard X-ray observations (>2 keV) in finding these binary AGNs. A high level of star formation combined with a very low L{sub [O{sub III}]/L{sub 2-10 keV}} ratio cause the AGN to be missed in optical observations. {sup 12}CO observations of the (3-2) and (2-1) lines indicate large amounts of molecular gas in the system that could be driven toward the black holes during the violent galaxy collision and be keymore » to fueling the binary AGN. Mrk 739E has a high Eddington ratio of 0.71 and a small black hole (log M{sub BH} = 7.05 {+-} 0.3) consistent with an efficiently accreting AGN. Other than NGC 6240, this stands as the nearest case of a binary AGN discovered to date.« less

Authors:
; ; ; ; ;  [1]; ;  [2];  [3]
  1. Astronomy Department, University of Maryland, College Park, MD (United States)
  2. Institute for Astronomy, University of Hawaii, Honolulu, HI (United States)
  3. Department of Physics, Yale University, New Haven, CT (United States)
Publication Date:
OSTI Identifier:
21562546
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 735; Journal Issue: 2; Other Information: DOI: 10.1088/2041-8205/735/2/L42; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; GALAXY NUCLEI; HARD X RADIATION; INTERACTIONS; SPATIAL RESOLUTION; X-RAY GALAXIES; X-RAY SOURCES; COSMIC RAY SOURCES; COSMIC X-RAY SOURCES; ELECTROMAGNETIC RADIATION; GALAXIES; IONIZING RADIATIONS; RADIATION SOURCES; RADIATIONS; RESOLUTION; X RADIATION

Citation Formats

Koss, Michael, Mushotzky, Richard, Veilleux, Sylvain, Vasudevan, Ranjan, Miller, Neal, Trippe, Margaret, Treister, Ezequiel, Sanders, D B, and Schawinski, Kevin. CHANDRA DISCOVERY OF A BINARY ACTIVE GALACTIC NUCLEUS IN Mrk 739. United States: N. p., 2011. Web. doi:10.1088/2041-8205/735/2/L42.
Koss, Michael, Mushotzky, Richard, Veilleux, Sylvain, Vasudevan, Ranjan, Miller, Neal, Trippe, Margaret, Treister, Ezequiel, Sanders, D B, & Schawinski, Kevin. CHANDRA DISCOVERY OF A BINARY ACTIVE GALACTIC NUCLEUS IN Mrk 739. United States. https://doi.org/10.1088/2041-8205/735/2/L42
Koss, Michael, Mushotzky, Richard, Veilleux, Sylvain, Vasudevan, Ranjan, Miller, Neal, Trippe, Margaret, Treister, Ezequiel, Sanders, D B, and Schawinski, Kevin. 2011. "CHANDRA DISCOVERY OF A BINARY ACTIVE GALACTIC NUCLEUS IN Mrk 739". United States. https://doi.org/10.1088/2041-8205/735/2/L42.
@article{osti_21562546,
title = {CHANDRA DISCOVERY OF A BINARY ACTIVE GALACTIC NUCLEUS IN Mrk 739},
author = {Koss, Michael and Mushotzky, Richard and Veilleux, Sylvain and Vasudevan, Ranjan and Miller, Neal and Trippe, Margaret and Treister, Ezequiel and Sanders, D B and Schawinski, Kevin},
abstractNote = {We have discovered a binary active galactic nucleus (AGN) in the galaxy Mrk 739 using Chandra and Swift BAT. We find two luminous (L{sub 2-10 keV} = 1.1 x 10{sup 43} and 1.0 x 10{sup 42} erg s{sup -1}), unresolved nuclei with a projected separation of 3.4 kpc (5.''8 {+-} 0.''1) coincident with two bulge components in the optical image. The western X-ray source (Mrk 739W) is highly variable (x 2.5) during the 4 hr Chandra observation and has a very hard spectrum consistent with an AGN. While the eastern component was already known to be an AGN based on the presence of broad optical recombination lines, Mrk 739W shows no evidence of being an AGN in optical, UV, and radio observations, suggesting the critical importance of high spatial resolution hard X-ray observations (>2 keV) in finding these binary AGNs. A high level of star formation combined with a very low L{sub [O{sub III}]/L{sub 2-10 keV}} ratio cause the AGN to be missed in optical observations. {sup 12}CO observations of the (3-2) and (2-1) lines indicate large amounts of molecular gas in the system that could be driven toward the black holes during the violent galaxy collision and be key to fueling the binary AGN. Mrk 739E has a high Eddington ratio of 0.71 and a small black hole (log M{sub BH} = 7.05 {+-} 0.3) consistent with an efficiently accreting AGN. Other than NGC 6240, this stands as the nearest case of a binary AGN discovered to date.},
doi = {10.1088/2041-8205/735/2/L42},
url = {https://www.osti.gov/biblio/21562546}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 735,
place = {United States},
year = {Sun Jul 10 00:00:00 EDT 2011},
month = {Sun Jul 10 00:00:00 EDT 2011}
}