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Title: Abundance patterns in the interstellar medium of early-type galaxies observed with Suzaku

We have analyzed 17 early-type galaxies, 13 ellipticals and 4 S0 galaxies, observed with Suzaku, and investigated metal abundances (O, Mg, Si, and Fe) and abundance ratios (O/Fe, Mg/Fe, and Si/Fe) in the interstellar medium (ISM). The emission from each on-source region, which is four times the effective radius, r {sub e}, is reproduced with one-temperature (1T) or two-temperature (2T) thermal plasma models as well as a multi-temperature model, using APEC plasma code version 2.0.1. The multi-temperature model gave almost the same abundances and abundance ratios with the 1T or 2T models. The weighted averages of the O, Mg, Si, and Fe abundances of all the sample galaxies derived from the multi-temperature model fits are 0.83 ± 0.04, 0.93 ± 0.03, 0.80 ± 0.02, and 0.80 ± 0.02 solar, respectively, in solar units according to the solar abundance table by Lodders in 2003. These abundances show no significant dependence on the morphology and environment. The systematic differences in the derived metal abundances between versions 2.0.1 and 1.3.1 of the APEC plasma codes were investigated. The derived O and Mg abundances in the ISM agree with the stellar metallicity within an aperture with a radius of one r {sub e} derivedmore » from optical spectroscopy. From these results, we discuss the past and present Type Ia supernova rates and star formation histories in early-type galaxies.« less
Authors:
 [1] ; ;  [2] ;  [3]
  1. Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan)
  2. Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)
  3. Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)
Publication Date:
OSTI Identifier:
22351390
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 783; 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; ABUNDANCE; APERTURES; DATA; EMISSION; METALLICITY; METALS; PLASMA; SPECTROSCOPY; STARS; X RADIATION; X-RAY GALAXIES