Aperture Synthesis Observations of Molecular and Atomic Gas in the Wolf- Rayet Starburst Galaxy

Abstract

view Abstract Citations (76) References (39) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Aperture Synthesis Observations of Molecular and Atomic Gas in the Wolf- Rayet Starburst Galaxy Kobulnicky, Henry A. ; Dickey, John M. ; Sargent, Anneila I. ; Hogg, David E. ; Conti, Peter S. Abstract We present aperture synthesis observations of the atomic (H I) and molecular (CO) gas in the Wolf-Rayet starburst galaxy Henize 2-10 (He 2- 10). Our ^12^CO (1-0) observations from the Owens Valley Radio Observatory represent the first aperture synthesis data on molecular gas in a blue compact galaxy. The ^12^CO (1-0) data reveal a rotating disk or bar of molecular material with a 30" x 5" elongation to the Southeast which we interpret as a tidal tail. We also see a kinematically distinct CO feature with a molecular gas mass of at least 4.0 x 10^6^ M_sun_, perhaps indicative of a collision or interaction. The peak of the molecular gas distribution is offset by ~100 pc from the optical peak containing a population of some 400 Wolf-Rayet stars. The rotation curve derived from our CO velocity field indicates that, unless the inclination of He 2-10 is extremely low, young starburst knots in the nucleus, which have been termed "proto globular clusters," comprise up to half of the dynamical mass in the inner 70 pc. A search for HI companions detected none to a limit of < 3.5 x 10^6^ M_sun_. The global H I velocity field is predominantly solid body, and shows a small elongation to the Southeast which might be regarded as a tidal tail. This H I feature points in the same direction as the elongation seen in CO, suggesting a past merger or galactic interaction. High spatial resolution maps reveal a low H I surface brightness in the vicinity of the two starburst regions which we interpret as a real dearth of H I, perhaps the result of a replacement effect by molecular gas which fills this region. We address the bearing of these data on several scenarios proposed to explain the history of the star formation in He 2-10. Our preferred interpretation involves a moderately advanced merger between two dwarf galaxies. Another more speculative interpretation involving the accretion of small gas clouds in the mass range of a few x 10^6^ M_sun_ is discussed. Publication: The Astronomical Journal Pub Date: July 1995 DOI: 10.1086/117500 Bibcode: 1995AJ....110..116K Keywords: GALAXIES: STARSBURST; GALAXIES: ABUNDANCES; GALAXIES: INDIVIDUAL: HENIZE 2-10 full text sources ADS | data products SIMBAD (12) NED (1)