Hostname: page-component-8448b6f56d-t5pn6 Total loading time: 0 Render date: 2024-04-24T18:49:01.361Z Has data issue: false hasContentIssue false

Metal abundances in the hot ISM of early-type galaxies

Published online by Cambridge University Press:  21 October 2010

Philip J. Humphrey
Affiliation:
Department of Physics & Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697, USA email: phumphre@uci.edu
David A. Buote
Affiliation:
Department of Physics & Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697, USA email: phumphre@uci.edu
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Understanding the process of metal enrichment is one of the key problems for our picture of structure formation and evolution, in which early-type galaxies are a crucial ingredient. X-ray observations provide a powerful tool for measuring the metal distributions in their hot ISM, which is shaped by their entire history of star-formation, evolution and feedback. In Fig 1 (left panel), we summarize the results of a Chandra survey of metals in early-type galaxies, supplemented with Suzaku data (Humphrey & Buote 2006, P. Humphrey et al., in prep.). Chandra is particularly suited to this study, as it enables temperature gradients and X-ray point sources to be resolved, mitigating two important sources of bias (e.g., Buote & Fabian 1998; Fabbiano et al. 1994). We found on average that the ISM is at least as metal-rich as the stars, and we did not find the problematical, highly sub-solar, abundances historically reported. The abundance ratios of O, Ne, Mg, Si and S with respect to Fe are similar to the centres of massive groups and clusters, suggesting homology in the enrichment process over a wide mass range. Finally, using high-quality Suzaku data, we were able to resolve, for the first time in a galaxy-scale (≲1013M) object, a radial abundance gradient similar to those seen in some bright galaxy groups (Fig. 1, right panel).

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2010

References

Buote, D. A. & Fabian, A. C. 1998, MNRAS 296, 977CrossRefGoogle Scholar
Buote, D. A. et al. 2003, ApJ 595, 151CrossRefGoogle Scholar
Buote, D. A., Brighenti, F., & Mathews, W. G. 2004, ApJL 607, L91CrossRefGoogle Scholar
Fabbiano, G., Kim, D.-W., & Trinchieri, G. 1994, ApJ 429, 94CrossRefGoogle Scholar
Humphrey, P. J. & Buote, D. A. 2006, ApJ 639, 136CrossRefGoogle Scholar