Abundance Patterns in the Interstellar Medium of Early-type Galaxies Observed with Suzaku

Abstract

We have analyzed 17 early-type galaxies, 13 ellipticals and 4 S0's, 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 4 times effective radius, r_e, is reproduced with one- or two- temperature thermal plasma models as well as a multi-temperature model, using APEC plasma code v2.0.1. 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 (2003). These abundances show no significant dependence on the morphology and environment. The systematic differences in the derived metal abundances between the version 2.0.1 and 1.3.1 of APEC plasma codes were investigated. The derived O and Mg abundances in the ISM agree with the stellar metallicity within a aperture with a radius of one r_e derived from optical spectroscopy. From these results, we discuss the past and present SN Ia rates and star formation histories in early-type galaxies.

32 pages, 23 figures, accepted for publication in ApJ

References in corpus (5)

• Population Synthesis in the Blue IV: Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations
• XMM-Newton high-resolution spectroscopy reveals the chemical evolution of M 87
• Type Ia and II supernovae contributions to the metal enrichment in intra-cluster medium observed with Suzaku
• X-ray observations of three young, early-type galaxies
• The link between the masses and central stellar populations of S0 galaxies

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