POST-STARBURST TIDAL TAILS IN THE ARCHETYPICAL ULTRA LUMINOUS INFRARED GALAXY Arp 220

Journal Article · Sun Jul 01 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/753/1/78· OSTI ID:22036897

Taniguchi, Y; Matsubayashi, K; Kajisawa, M; Shioya, Y; Ideue, Y ^[1]; Ohyama, Y ^[2]; Nagao, T ^[3]; Murayama, T ^[4]; Koda, J ^[5]

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1. Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan)
2. Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan, R.O.C (China)
3. Department of Astronomy, Kyoto University, Kitashirakawa Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)
4. Astronomical Institute, Tohoku University, Aramaki, Aoba, Sendai 980-8578 (Japan)
5. Department of Physics and Astronomy, SUNY Stony Brook, Stony Brook, NY 11794-3800 (United States)

We present our new deep optical imaging and long-slit spectroscopy for Arp 220, the archetypical ultra luminous infrared galaxy in the local universe. Our sensitive H{alpha} imaging has newly revealed large-scale H{alpha} absorption, i.e., post-starburst regions in this merger. One is found in the eastern superbubble and the other is in the two tidal tails that are clearly revealed in our deep optical imaging. The size of the H{alpha} absorption region in the eastern bubble is 5 kpc Multiplication-Sign 7.5 kpc, and the observed H{alpha} equivalent widths are {approx}2 Angstrom-Sign {+-} 0.2 Angstrom-Sign . The sizes of the northern and southern H{alpha}-absorption tidal tails are {approx}5 kpc Multiplication-Sign 10 kpc and {approx}6 kpc Multiplication-Sign 20 kpc, respectively. The observed H{alpha} equivalent widths range from 4 Angstrom-Sign to 7 Angstrom-Sign . In order to explain the presence of the two post-starburst tails, we suggest a possible multiple-merger scenario for Arp 220 in which two post-starburst disk-like structures merged into one, causing the two tails. This favors Arp 220 as a multiple merging system composed of four or more galaxies arising from a compact group of galaxies. Taking our new results into account, we discuss a star formation history in the last 1 Gyr in Arp 220.

• OSTI ID: 22036897
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 753; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
ABSORPTION SPECTROSCOPY
EMISSION SPECTROSCOPY
GALAXIES
LINE WIDTHS
STAR EVOLUTION
STARS
UNIVERSE