The DEEP2 Galaxy Redshift Survey: AEGIS Observations of a Dual AGN at z = 0.7

We present evidence of a dual active galactic nucleus (AGN) within an early-type galaxy at z = 0.709 in the extended Groth strip. The galaxy lies on the red sequence, with absolute magnitude MB = -21.0 (AB, with h = 0.7) and rest-frame color U - B = 1.38. Its optical spectrum shows strong, double-peaked [O III] emission lines and weak Hβ emission, with Seyfert-like line ratios. The two narrow peaks are separated by 630 km s-1 in velocity and arise from two distinct regions, spatially resolved in the DEIMOS spectrum, with a projected physical separation of 1.2 kpc. HST ACS imaging shows an early-type (E/S0) galaxy with hints of disturbed structure, consistent with the remnant of a dissipationless merger. Multiwavelength photometric information from the AEGIS consortium confirms the identification of a dust-obscured AGN in an early-type galaxy, with detections in X-ray, optical, infrared, and radio wave bands. These data are most readily explained as a single galaxy harboring two AGNs—the first such system to be observed in an otherwise typical early-type galaxy.

[1]  E. L. Wright,et al.  The All-Wavelength Extended Groth Strip International Survey (AEGIS) Data Sets , 2006, astro-ph/0607355.

[2]  C. Conselice,et al.  AEGIS20: A Radio Survey of the Extended Groth Strip , 2006, astro-ph/0607271.

[3]  National Radio Astronomy Observatory,et al.  A Compact Supermassive Binary Black Hole System , 2006, astro-ph/0604042.

[4]  Nrl,et al.  X-ray detection of the proto supermassive binary black hole at the centre of Abell 400 , 2006, astro-ph/0603272.

[5]  J. Newman,et al.  On the Origin of [O II] Emission in Red-Sequence and Poststarburst Galaxies , 2005, astro-ph/0512446.

[6]  P. Dokkum,et al.  The Recent and Continuing Assembly of Field Elliptical Galaxies by Red Mergers , 2005, astro-ph/0506661.

[7]  A. Connolly,et al.  The DEEP2 Galaxy Redshift Survey: The Galaxy Luminosity Function to z ~ 1 , 2005, astro-ph/0506041.

[8]  L. Ho,et al.  A Comparison of Stellar and Gaseous Kinematics in the Nuclei of Active Galaxies , 2005, astro-ph/0503675.

[9]  D. Schiminovich,et al.  New Constraints on the Star Formation Histories and Dust Attenuation of Galaxies in the Local Universe from GALEX , 2004, astro-ph/0411354.

[10]  M. Milosavljevic,et al.  Massive Black Hole Binary Evolution , 2004, astro-ph/0410364.

[11]  Hans-Walter Rix,et al.  On the Black Hole Mass-Bulge Mass Relation , 2004, astro-ph/0402376.

[12]  Timothy M. Heckman,et al.  The host galaxies of active galactic nuclei , 2003 .

[13]  R. Zavala,et al.  Breaking All the Rules: The Compact Symmetric Object 0402+379 , 2003, astro-ph/0310663.

[14]  G. Bruzual,et al.  Stellar population synthesis at the resolution of 2003 , 2003, astro-ph/0309134.

[15]  M. Eracleous,et al.  Completion of a Survey and Detailed Study of Double-peaked Emission Lines in Radio-loud Active Galactic Nuclei , 2003, astro-ph/0309149.

[16]  L. Maraschi,et al.  Arp 299: A Second Merging System with Two Active Nuclei? , 2003, astro-ph/0306436.

[17]  J. Brinkmann,et al.  The Host Galaxies of AGN , 2003, astro-ph/0304239.

[18]  L. Ho,et al.  Detailed Structural Decomposition of Galaxy Images , 2002, astro-ph/0204182.

[19]  A. Rest,et al.  Galaxy cores as relics of black hole mergers , 2001, astro-ph/0110185.

[20]  S. Veilleux,et al.  The Biconical Outflow in the Seyfert Galaxy NGC 2992 , 2000, astro-ph/0010134.

[21]  C. Kochanek,et al.  Why Quasar Pairs are Binary Quasars and Not Gravitational Lenses , 1997, astro-ph/9710165.

[22]  F. Macchetto,et al.  Jet-Driven Motions in the Narrow-Line Region of NGC 1068 , 1997, astro-ph/9801253.

[23]  M. S. Oey,et al.  Atlas of quasar energy distributions , 1994 .

[24]  Kindler-Rohrborn,et al.  In press , 1994, Molecular carcinogenesis.

[25]  T. Heckman,et al.  Emission-line profiles and kinematics of the narrow-line region in Seyfert and radio galaxies , 1981 .

[26]  M. Rees,et al.  Massive black hole binaries in active galactic nuclei , 1980, Nature.

[27]  J. Newman,et al.  Accepted for publication in ApJ Letters Preprint typeset using L ATEX style emulateapj v. 6/22/04 AEGIS: THE COLOR-MAGNITUDE RELATION FOR X-RAY SELECTED AGN , 2006 .

[28]  G. Matt,et al.  The early stage of a cosmic collision? XMM-Newton unveils two obscured AGN in the galaxy pair ESO509-IG066 , 2005 .

[29]  Yong-Seo Park,et al.  ApJ, in press , 1999 .

[30]  Jose Luis. Sersic,et al.  Atlas de Galaxias Australes , 1968 .