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Title: The dependence of galactic outflows on the properties and orientation of zCOSMOS galaxies at z ∼ 1

We present an analysis of cool outflowing gas around galaxies, traced by Mg II absorption lines in the coadded spectra of a sample of 486 zCOSMOS galaxies at 1 ≤ z ≤ 1.5. These galaxies span a range of stellar masses (9.45 ≤ log{sub 10}[M {sub *}/M {sub ☉}] ≤ 10.7) and star formation rates (0.14 ≤ log{sub 10}[SFR/M {sub ☉} yr{sup –1}] ≤ 2.35). We identify the cool outflowing component in the Mg II absorption and find that the equivalent width of the outflowing component increases with stellar mass. The outflow equivalent width also increases steadily with the increasing star formation rate of the galaxies. At similar stellar masses, the blue galaxies exhibit a significantly higher outflow equivalent width as compared to red galaxies. The outflow equivalent width shows strong correlation with the star formation surface density (Σ{sub SFR}) of the sample. For the disk galaxies, the outflow equivalent width is higher for the face-on systems as compared to the edge-on ones, indicating that for the disk galaxies, the outflowing gas is primarily bipolar in geometry. Galaxies typically exhibit outflow velocities ranging from –150 km s{sup –1} ∼–200 km s{sup –1} and, on average, the face-on galaxies exhibit highermore » outflow velocity as compared to the edge-on ones. Galaxies with irregular morphologies exhibit outflow equivalent width as well as outflow velocities comparable to face on disk galaxies. These galaxies exhibit mass outflow rates >5-7 M {sub ☉} yr{sup –1} and a mass loading factor (η = M-dot {sub out}/SFR) comparable to the star formation rates of the galaxies.« less
Authors:
 [1] ; ; ;  [2] ;  [3] ; ; ;  [4] ;  [5] ;  [6] ;  [7] ; ; ;  [8] ;  [9] ;  [10] ;  [11] ; ;  [12] ;  [13] more »; « less
  1. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
  2. Institute for Astronomy, ETH Zürich, Wolfgang-Pauli-Strasse 27, CH-8093 Zürich (Switzerland)
  3. Institut de Recherche en Astrophysique et Planétologie, CNRS, 14, avenue Edouard Belin, F-31400 Toulouse (France)
  4. Laboratoire d'Astrophysique de Marseille, CNRS/Aix-Marseille Université, 38 rue Frédéric Joliot-Curie, F-13388, Marseille cedex 13 (France)
  5. European Southern Observatory, Garching (Germany)
  6. Dipartimento di Astronomia, Universita di Padova, Padova (Italy)
  7. INAF-IASF Milano, Milan (Italy)
  8. INAF Osservatorio Astronomico di Bologna, Bologna (Italy)
  9. Max Planck Institut für Extraterrestrische Physik, Garching (Germany)
  10. Kapteyn Astronomical Institute, University of Groningen, PO Box 800, NL-9700 AV Groningen (Netherlands)
  11. INAF-Osservatorio Astronomico di Trieste, Trieste (Italy)
  12. SUPA, The University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 1BD (United Kingdom)
  13. INAF Osservatorio Astronomico di Brera, Milan (Italy)
Publication Date:
OSTI Identifier:
22370399
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 794; 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; ABSORPTION; COMPARATIVE EVALUATIONS; CORRELATIONS; COSMIC GASES; DENSITY; EVOLUTION; GALAXIES; MASS; RED SHIFT; SPECTRA; STARS; ULTRAVIOLET RADIATION