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Title: THE GAS INFLOW AND OUTFLOW RATE IN STAR-FORMING GALAXIES AT z ∼ 1.4

We try to constrain the gas inflow and outflow rate of star-forming galaxies at z ∼ 1.4 by employing a simple analytic model for the chemical evolution of galaxies. The sample is constructed based on a large near-infrared spectroscopic sample observed with Subaru/FMOS. The gas-phase metallicity is measured from the [N II] λ6584/Hα emission line ratio and the gas mass is derived from the extinction corrected Hα luminosity by assuming the Kennicutt-Schmidt law. We constrain the inflow and outflow rate from the least-χ{sup 2} fittings of the observed gas-mass fraction, stellar mass, and metallicity with the analytic model. The joint χ{sup 2} fitting shows that the best-fit inflow rate is ∼1.8 and the outflow rate is ∼0.6 in units of star-formation rate. By applying the same analysis to the previous studies at z ∼ 0 and z ∼ 2.2, it is shown that both the inflow and outflow rates decrease with decreasing redshift, which implies the higher activity of gas flow process at higher redshift. The decreasing trend of the inflow rate from z ∼ 2.2 to z ∼ 0 agrees with that seen in previous observational works with different methods, though the absolute value is generally larger than in previousmore » works. The outflow rate and its evolution from z ∼ 2.2 to z ∼ 0 obtained in this work agree well with the independent estimations in previous observational works.« less
Authors:
 [1] ; ;  [2] ;  [3] ;  [4] ;  [5] ; ;  [6]
  1. Division of Optical and IR Astronomy, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka 181-8588 (Japan)
  2. Department of Astronomy, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
  3. Astronomical Institute, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan)
  4. Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa city, Chiba 277-8583 (Japan)
  5. Institute for Cosmic Ray Research, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8582 (Japan)
  6. Department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)
Publication Date:
OSTI Identifier:
22364730
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 798; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMOLOGY; EMISSION SPECTRA; GALACTIC EVOLUTION; GALAXIES; GAS-FLOW PROCESSES; INFRARED SPECTRA; LUMINOSITY; MASS; METALLICITY; NEAR INFRARED RADIATION; RED SHIFT; STAR EVOLUTION; STARS