Stellar and gaseous nuclear disks observed in nearby (U)LIRGs

Journal Article · Thu Mar 20 04:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/784/1/70· OSTI ID:22351477

Medling, Anne M. ^[1]; U, Vivian ^[2]; Guedes, Javiera ^[3]; Max, Claire E.; Holden, Bradford ^[4]; Mayer, Lucio; Roškar, Rok ^[5]; Armus, Lee ^[6]; Sanders, David ^[7]

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1. Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia)
2. Department of Physics and Astronomy, University of California, Riverside, 900 University Avenue, Riverside, CA 92521 (United States)
3. Institute for Astronomy, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich (Switzerland)
4. Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)
5. Institute for Theoretical Physics, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland)
6. Spitzer Science Center, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States)
7. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

We present near-infrared integral field spectroscopy of the central kiloparsec of 17 nearby luminous and ultra-luminous infrared galaxies undergoing major mergers. These observations were taken with OSIRIS assisted by the Keck I and II Adaptive Optics systems, providing spatial resolutions of a few tens of parsecs. The resulting kinematic maps reveal gas disks in at least 16 out of 19 nuclei and stellar disks in 11 out of 11 nuclei observed in these galaxy merger systems. In our late-stages mergers, these disks are young (stellar ages <30 Myr) and likely formed as gas disks that became unstable to star formation during the merger. On average, these disks have effective radii of a few hundred parsecs, masses between 10{sup 8} and 10{sup 10} M {sub ☉}, and v/σ between 1 and 5. These disks are similar to those created in high-resolution hydrodynamical simulations of gas-rich galaxy mergers, and favor short coalescence times for binary black holes. The few galaxies in our sample in earlier stages of mergers have disks that are larger (r {sub eff} ∼ 200-1800 pc) and are likely remnants of the galactic disks that have not yet been completely disrupted by the merger.

• OSTI ID: 22351477
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 784; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BLACK HOLES
COALESCENCE
GALAXIES
GALAXY NUCLEI
INTERACTIONS
LUMINOSITY
MASS
NEAR INFRARED RADIATION
SIMULATION
SPATIAL RESOLUTION
SPECTROSCOPY
STARS