CHANDRA OBSERVATIONS OF GALAXY ZOO MERGERS: FREQUENCY OF BINARY ACTIVE NUCLEI IN MASSIVE MERGERS

Journal Article · Tue Jul 10 00:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/753/2/165· OSTI ID:22039351

Teng, Stacy H ^[1]; Schawinski, Kevin; Urry, C Megan; Bonning, Erin W ^[2]; Darg, Dan W; Kaviraj, Sugata; Lintott, Chris J ^[3]; Oh, Kyuseok ^[4]; Cardamone, Carolin N ^[5]; Keel, William C ^[6]; Simmons, Brooke D ^[7]; Treister, Ezequiel ^[8]

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1. Observational Cosmology Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States)
2. Department of Physics, Yale University, New Haven, CT 06511 (United States)
3. Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)
4. Department of Astronomy, Yonsei University, Seoul 120-749 (Korea, Republic of)
5. Harriet W. Sheridan Center for Teaching and Learning, Brown University, P.O. Box 1912, Providence, RI 02912 (United States)
6. Department of Physics and Astronomy, 206 Gallalee Hall, 514 University Boulevard, University of Alabama, Tuscaloosa, AL 35487-034 (United States)
7. Yale Center for Astronomy and Astrophysics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States)
8. Departamento de Astronomia, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile)

We present the results from a Chandra pilot study of 12 massive galaxy mergers selected from Galaxy Zoo. The sample includes major mergers down to a host galaxy mass of 10{sup 11} M{sub Sun} that already have optical active galactic nucleus (AGN) signatures in at least one of the progenitors. We find that the coincidences of optically selected active nuclei with mildly obscured (N{sub H} {approx}< 1.1 Multiplication-Sign 10{sup 22} cm{sup -2}) X-ray nuclei are relatively common (8/12), but the detections are too faint (<40 counts per nucleus; f{sub 2-10keV} {approx}< 1.2 Multiplication-Sign 10{sup -13} erg s{sup -1} cm{sup -2}) to reliably separate starburst and nuclear activity as the origin of the X-ray emission. Only one merger is found to have confirmed binary X-ray nuclei, though the X-ray emission from its southern nucleus could be due solely to star formation. Thus, the occurrences of binary AGNs in these mergers are rare (0%-8%), unless most merger-induced active nuclei are very heavily obscured or Compton thick.

• OSTI ID: 22039351
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 753; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
DETECTION
GALAXY NUCLEI
GAMMA ASTRONOMY
MASS
PHOTON EMISSION
STARS
X RADIATION
X-RAY GALAXIES