THE ABUNDANCE PATTERN IN THE HOT ISM OF NGC 4472: INSIGHTS AND ANOMALIES
| Autor: | Michael Loewenstein, David S. Davis |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Physics
Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies Spectral line Luminosity Stars Supernova Space and Planetary Science Nucleosynthesis Astrophysics of Galaxies (astro-ph.GA) Stellar mass loss Elliptical galaxy Astrophysics::Solar and Stellar Astrophysics Ejecta Astrophysics::Galaxy Astrophysics |
| Zdroj: | The Astrophysical Journal. 716:384-397 |
| ISSN: | 1538-4357 0004-637X |
| DOI: | 10.1088/0004-637x/716/1/384 |
| Popis: | Important clues to the chemical and dynamical history of elliptical galaxies are encoded in the abundances of heavy elements in the X-ray emitting plasma. We derive the hot ISM abundance pattern in inner and outer regions of NGC 4472 from analysis of Suzaku spectra, supported by analysis of co-spatial XMM-Newton spectra. The low background and relatively sharp spectral resolution of the Suzaku XIS detectors, combined with the high luminosity and temperature in NGC 4472, enable us to derive a particularly extensive abundance pattern that encompasses O, Ne, Mg, Al, Si, S, Ar, Ca, Fe, and Ni in both regions. We apply simple chemical evolution models to these data, and conclude that the abundances are best explained by a combination of alpha-element enhanced stellar mass loss and direct injection of Type Ia supernova (SNIa) ejecta. We thus confirm the inference, based on optical data, that the stars in elliptical galaxies have supersolar alpha/Fe ratios, but find that that the present-day SNIa rate is 4-6 times lower than the standard value. We find SNIa yield sets that reproduce Ca and Ar, or Ni, but not all three simultaneously. The low abundance of O relative to Ne and Mg implies that standard core collapse nucleosynthesis models overproduce O by a factor of 2. Comment: 37 pages, including 23 figures, uses aastex.cls; accepted for publication in ApJ |
| Databáze: | OpenAIRE |
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