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Title: FAR-ULTRAVIOLET OBSERVATIONS OF OUTFLOWS FROM INFRARED-LUMINOUS GALAXIES

We obtained medium-resolution ultraviolet (UV) spectra between 1150 and 1450 A of the four UV-bright, infrared-luminous starburst galaxies IRAS F08339+6517, NGC 3256, NGC 6090, and NGC 7552 using the Cosmic Origins Spectrograph on board the Hubble Space Telescope. The selected sightlines toward the starburst nuclei probe the properties of the recently formed massive stars and the physical conditions in the starburst-driven galactic superwinds. Despite being metal-rich and dusty, all four galaxies are strong Ly{alpha} emitters with equivalent widths ranging between 2 and 13 A. The UV spectra show strong P Cygni-type high-ionization features indicative of stellar winds and blueshifted low-ionization lines formed in the interstellar and circumgalactic medium. We detect outflowing gas with bulk velocities of {approx}400 km s{sup -1} and maximum velocities of almost 900 km s{sup -1}. These are among the highest values found in the local universe and comparable to outflow velocities found in luminous Lyman-break galaxies at intermediate and high redshift. The outflow velocities are unlikely to be high enough to cause escape of material from the galactic gravitational potential. However, the winds are significant for the evolution of the galaxies by transporting heavy elements from the starburst nuclei and enriching the galaxy halos. The derivedmore » mass outflow rates of {approx}100 M{sub Sun} yr{sup -1} are comparable to or even higher than the star formation rates. The outflows can quench star formation and ultimately regulate the starburst as has been suggested for high-redshift galaxies.« less
Authors:
;  [1] ;  [2] ;  [3] ;  [4]
  1. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
  2. Department of Physics and Astronomy, The University of Toledo, Toledo, OH 43606 (United States)
  3. Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States)
  4. Observatoire de Geneve, 51 chemin des Maillettes, CH 1290 Versoix (Switzerland)
Publication Date:
OSTI Identifier:
22121789
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 772; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMIC NUCLEI; FAR ULTRAVIOLET RADIATION; GALACTIC EVOLUTION; GALAXIES; GRAVITATION; INFRARED SPECTRA; LYMAN LINES; RED SHIFT; RESOLUTION; STARS; STELLAR WINDS; TELESCOPES; ULTRAVIOLET SPECTRA; UNIVERSE; VELOCITY