A CHANDRA X-RAY ANALYSIS OF ABELL 1664: COOLING, FEEDBACK, AND STAR FORMATION IN THE CENTRAL CLUSTER GALAXY

Journal Article · Wed May 20 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/697/1/867; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21300538

Kirkpatrick, C C; McNamara, B R; Kazemzadeh, F; Cavagnolo, K W ^[1]; Rafferty, D A; BIrzan, L ^[2]; Nulsen, P E. J. ^[3]; Wise, M W ^[4]; Gitti, M ^[5]

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1. Department of Physics and Astronomy, University of Waterloo, 200 University Ave. W., Waterloo, ON N2L 3G1 (Canada)
2. Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)
3. Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)
4. Astronomical Institute 'Anton Pannekoek', University of Amsterdam, Krusilaan 403, 1098 SJ Amsterdam (Netherlands)
5. INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy)

The brightest cluster galaxy (BCG) in the Abell 1664 cluster is unusually blue and is forming stars at a rate of {approx} 23 M {sub sun} yr{sup -1}. The BCG is located within 5 kpc of the X-ray peak, where the cooling time of 3.5 x 10{sup 8} yr and entropy of 10.4 keV cm{sup 2} are consistent with other star-forming BCGs in cooling flow clusters. The center of A1664 has an elongated, 'barlike' X-ray structure whose mass is comparable to the mass of molecular hydrogen, {approx}10{sup 10} M {sub sun} in the BCG. We show that this gas is unlikely to have been stripped from interloping galaxies. The cooling rate in this region is roughly consistent with the star formation rate, suggesting that the hot gas is condensing onto the BCG. We use the scaling relations of BIrzan et al. to show that the active galactic nucleus (AGN) is underpowered compared to the central X-ray cooling luminosity by roughly a factor of three. We suggest that A1664 is experiencing rapid cooling and star formation during a low state of an AGN feedback cycle that regulates the rates of cooling and star formation. Modeling the emission as a single-temperature plasma, we find that the metallicity peaks 100 kpc from the X-ray center, resulting in a central metallicity dip. However, a multi-temperature cooling flow model improves the fit to the X-ray emission and is able to recover the expected, centrally peaked metallicity profile.

• OSTI ID: 21300538
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 697; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
COOLING TIME
ENTROPY
FLOW MODELS
GALAXY CLUSTERS
LUMINOSITY
SIMULATION
STARS
X RADIATION
X-RAY GALAXIES