1. An Infrared Survey of Brightest Cluster Galaxies. I
- Author
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Nicholas Zufelt, Stefi A. Baum, Megan Donahue, Helen Russell, Christopher P. O'Dea, Joel N. Bregman, George C. Privon, Andrew C. Fabian, Brian R. McNamara, Jacob Noel-Storr, Alice C. Quillen, Alastair C. Edge, Jaehong Park, and Craig L. Sarazin
- Subjects
Physics ,Luminous infrared galaxy ,Infrared excess ,Active galactic nucleus ,010308 nuclear & particles physics ,Infrared ,Star formation ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Galaxy ,Spitzer Space Telescope ,Space and Planetary Science ,0103 physical sciences ,ROSAT ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
We report on an imaging survey with the Spitzer Space Telescope of 62 brightest cluster galaxies with optical line emission. These galaxies are located in the cores of X-ray luminous clusters selected from the ROSAT All-Sky Survey. We find that about half of these sources have a sign of excess infrared emission; 22 objects out of 62 are detected at 70 microns, 18 have 8 to 5.8 micron flux ratios above 1.0 and 28 have 24 to 8 micron flux ratios above 1.0. Altogether 35 of 62 objects in our survey exhibit at least one of these signs of infrared excess. Four galaxies with infrared excesses have a 4.5/3.6 micron flux ratio indicating the presence of hot dust, and/or an unresolved nucleus at 8 microns. Three of these have high measured [OIII](5007A)/Hbeta flux ratios suggesting that these four, Abell 1068, Abell 2146, and Zwicky 2089, and R0821+07, host dusty active galactic nuclei (AGNs). 9 objects (including the four hosting dusty AGNs) have infrared luminosities greater than 10^11 L_sol and so can be classified as luminous infrared galaxies (LIRGs). Excluding the four systems hosting dusty AGNs, the excess mid-infrared emission in the remaining brightest cluster galaxies is likely related to star formation.
- Published
- 2008
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