2006/01/01 by Brian A. Keeney, Brian A. Keeney, John T. Stocke +6 · 17 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Dwarf galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Line (geometry) #Metallicity #Redshift #Solar mass #Space Telescope Imaging Spectrograph #Spectroscopy #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/508516
published in The Astronomical Journal 132(6), 2496-2506 (Institute of Physics) · 31 pages, 8 figures; AJ in press; a version with high resolution figures can be downloaded from http://casa.colorado.edu/~keeney/research/papers/IC691.pdf
openalex publication_date 2006/01/01 · arxiv created 2006/08/15 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We present optical and near-infrared images, H I 21 cm emission maps, optical spectroscopy, and Hubble Space Telescope Space Telescope Imaging Spectrograph ultraviolet spectroscopy of the QSO/galaxy pair SBS 1122+594/IC 691. The QSO sight line lies at a position angle of 27° from the minor axis of the nearby dwarf starburst galaxy IC 691 ( cz gal = 1204 ± 3 km s -1 , L B ∼ 0.09 L *, current star formation rate = 0.08-0.24 h M ⊙ yr -1 ) and 33 h kpc (6 6) from its nucleus. We find that IC 691 has an H I mass of M = (3.6 ± 0.1) × 10 8 M ⊙ and a dynamical mass of M dyn = (3.1 ± 0.5) × 10 10 h M ⊙ . The UV spectrum of SBS 1122+594 shows a metal-line (Lyα+C IV) absorber near the redshift of IC 691 at cz abs = 1110 ± 30 km s -1 . Since IC 691 is a dwarf starburst and the SBS 1122+594 sight line lies in the expected location for an outflowing wind, we propose that the best model for producing this metal-line absorber is a starburst wind from IC 691. We place consistent metallicity limits on IC 691 ([ Z / Z ⊙ ] ∼ -0.7) and the metal-line absorber ([ Z / Z ⊙ ] < -0.3). We also find that the galaxy's escape velocity at the absorber location is v esc = 80 ± 10 km s -1 and derive a wind velocity of v w = 160 ± 50 km s -1 . Thus, the evidence suggests that IC 691 produces an unbound starburst wind that escapes from its gravitational potential to transport metals and energy to the surrounding intergalactic medium.