Herschel Observations of FIR Emission Lines in Brightest Cluster Galaxies

Authors

A. C. Edge, Durham University, UK
J. B. R. Oonk, Leiden University, The Netherlands
R. Mittal, Rochester Institute of Technology
S. W. Allen, Stanford University
S. A. Baum, Rochester Institute of Technology
H. Böhringer, Max-Planck-Institut für extraterrestrische Physik, Germany
J. N. Bregman, University of Michigan
M. N. Bremer, H. H. Wills Physics Laboratory, UK
F. Combes, Observatoire de Paris, France
C. S. Crawford, Institute of Astronomy, UK
M. Donahue, Michigan State University
E. Egami, University of Arizona
A. C. Fabian, Institute of Astronomy, UK
Gary J. Ferland, University of KentuckyFollow
S. L. Hamer, Durham University, UK
N. A. Hatch, University of Nottingham, UK
W. Jaffe, Leiden University, The Netherlands
R. M. Johnstone, Institute of Astronomy, UK
B. R. McNamara, University of Waterloo, Canada
C. P. O'Dea, Rochester Institute of Technology
P. Popesso, Max-Planck-Institut für extraterrestrische Physik, Germany
A. C. Quillen, University of Rochester
P. Salomé, Observatoire de Paris, France
C. L. Sarazin, University of Virginia
G. M. Voit, Michigan State University
R. J. Wilman, University of Melbourne, Australia
M. W. Wise, Netherlands Institute for Radio Astronomy, The Netherlands

Abstract

The question of how much gas cools in the cores of clusters of galaxies has been the focus of many, multiwavelength studies in the past 30 years. In this letter we present the first detections of the strongest atomic cooling lines, [Cii], [Oi] and [Nii] in two strong cooling flow clusters, A1068 and A2597, using Herschel-PACS. These spectra indicate that the substantial mass of cold molecular gas (> 10⁹ M_⊙) known to be present in these systems is being irradiated by intense UV radiation, most probably from young stars. The line widths of these FIR lines indicate that they share dynamics similar but not identical to other ionised and molecular gas traced by optical, near-infrared and CO lines. The relative brightness of the FIR lines compared to CO and FIR luminosity is consistent with other star-forming galaxies indicating that the properties of the molecular gas clouds in cluster cores and the stars they form are not unusual. These results provide additional evidence for a reservoir of cold gas that is fed by the cooling of gas in the cores of the most compact clusters and provide important diagnostics of the temperature and density of the dense clouds this gas resides in.

Document Type

Letter to the Editor

Publication Date

7-2010

Notes/Citation Information

Published in Astronomy & Astrophysics, v. 518, article L46, p. 1-4.

Reproduced with permission from Astronomy & Astrophysics, © ESO, 2010

Digital Object Identifier (DOI)

http://dx.doi.org/10.1051/0004-6361/201014569

Repository Citation

Edge, A. C.; Oonk, J. B. R.; Mittal, R.; Allen, S. W.; Baum, S. A.; Böhringer, H.; Bregman, J. N.; Bremer, M. N.; Combes, F.; Crawford, C. S.; Donahue, M.; Egami, E.; Fabian, A. C.; Ferland, Gary J.; Hamer, S. L.; Hatch, N. A.; Jaffe, W.; Johnstone, R. M.; McNamara, B. R.; O'Dea, C. P.; Popesso, P.; Quillen, A. C.; Salomé, P.; Sarazin, C. L.; Voit, G. M.; Wilman, R. J.; and Wise, M. W., "Herschel Observations of FIR Emission Lines in Brightest Cluster Galaxies" (2010). Physics and Astronomy Faculty Publications. 170.
https://uknowledge.uky.edu/physastron_facpub/170