Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-18T01:28:21.054Z Has data issue: false hasContentIssue false

Why are some brightest cluster galaxies forming stars?

Published online by Cambridge University Press:  01 July 2007

Christopher P. O'Dea
Affiliation:
Department of Physics, Rochester Institute of Technology, Rochester, NY 14623, USA email: odea@cis.rit.edu
Alice Quillen
Affiliation:
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA email: aquillen@pas.rochester.edu
Nicholas Zufelt
Affiliation:
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA email: aquillen@pas.rochester.edu
Jaehong Park
Affiliation:
Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA email: aquillen@pas.rochester.edu
Alastair Edge
Affiliation:
Institute for Computational Cosmology, Department of Physics, Durham University, Durham DH1 3LE, UK email: alastair.edge@durham.ac.uk
Helen Russell
Affiliation:
Institute of Astronomy, Madingley Rd., Cambridge, CB3 0HA, UK email: hrr27@ast.cam.ac.uk, acf@ast.cam.ac.uk
Andy Fabian
Affiliation:
Institute of Astronomy, Madingley Rd., Cambridge, CB3 0HA, UK email: hrr27@ast.cam.ac.uk, acf@ast.cam.ac.uk
Stefi Baum
Affiliation:
Center for Imaging Science, Rochester Institute of Technology, Rochester, NY 14623, USA email: baum@cis.rit.edu
Rights & Permissions [Opens in a new window]

Abstract

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.

We present first results from an imaging survey with the Spitzer Space Telescope of 62 brightest cluster galaxies with optical line emission located in the cores of X-ray luminous clusters selected from the ROSAT All-Sky Survey. We find that 1/3 of these sources have signs of excess infrared emission; 22 objects of 62 are detected at 70 μm and 19 have 8 to 5.8 μm flux ratios above 0.98. The strength of the excess emission correlates with the luminosity of the optical emission lines. Excluding the four systems dominated by an AGN, the excess mid-infrared emission in the remaining brightest cluster galaxies is likely powered by star formation. We find a correlation between mass deposition rate from a cooling flow model for the X-ray emission and the star formation rate estimated from the infrared luminosity. The star formation rates are 1/10 to 1/100 of the mass deposition rates expected in the absence of heating suggesting that the re-heating of the ICM is generally very effective in reducing the amount of mass cooling from the hot phase.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2008

References

Allen, S. W. 2000, MNRAS, 315, 269CrossRefGoogle Scholar
Bell, E. F. 2003, ApJ, 586, 794CrossRefGoogle Scholar
Benson, A. J., Bower, R. G., Frenk, C. S., et al. 2003, ApJ, 599, 38CrossRefGoogle Scholar
Binney, J., 2004, MNRAS, 347, 1093CrossRefGoogle Scholar
Birzan, L., Rafferty, D. A., McNamara, B. R., et al. 2004, ApJ, 607, 800CrossRefGoogle Scholar
Bohringer, H., et al. 2004, A&A, 425, 367Google Scholar
Cardiel, N., Gorgas, J., & Aragon-Salamanca, A. 1998, Ap&SS, 263, 83Google Scholar
Crawford, C. S., Allen, S. W., Ebeling, H., et al. 1999, MNRAS, 306, 857CrossRefGoogle Scholar
Dunn, R. J. H. & Fabian, A. C. 2006, MNRAS, 373, 959CrossRefGoogle Scholar
Ebeling, H., Edge, A. C., Bohringer, H., et al. 1998, MNRAS, 301, 881CrossRefGoogle Scholar
Ebeling, H., Edge, A. C., Allen, S. W., et al. 2000, MNRAS, 318, 333CrossRefGoogle Scholar
Elbaz, D., Cesarsky, C. J., Chanial, P., et al. 2002, A&A, 384, 848Google Scholar
Fabian, A. C. 1994, ARA&A 32, 277Google Scholar
McNamara, B. R. & O'Connell, R. W. 1989, AJ, 98, 2018CrossRefGoogle Scholar
O'Dea, , et al. , 2007, in preparationGoogle Scholar
Peterson, J. R. & Fabian, A. C., 2006, Physics Reports, 427, 1CrossRefGoogle Scholar
Rafferty, D. A., McNamara, B. R., Nulsen, P. E. J., & Wise, M. W. 2006, ApJ, 652, 216CrossRefGoogle Scholar
Zufelt, N., et al. 2007, ApJS, in preparation.Google Scholar