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Constraints on molecular gas in cooling flows and powerful radio galaxiesWe searched for molecular gas in a heterogeneous sample of five radio-loud galaxies (three of which are inferred to be in cooling flow clusters) using the Swedish-European Southern Observatory (Swedish-ESO) Submillimeter Telescope. We do not detect CO in emission in any of the cluster sources at a 3 sigma level of typically 15 mK. White et al. (1991) have suggested column densities of N(sub H) approximately 10(exp 21)/sq cm in these clusters with a spatial covering factor of order unity and a total mass of M approximately 10(exp 12) solar mass. Our limits are inconsistent with these column densities and spatial covering factor unless the molecular gas is very cold (kinetic temperature close to 2.7 K) or there only a few clouds along each line of sight. We estimate minimum temperatures in the range approximately 20-30 K. We find that clouds of atomic and molecular hydrogen require strict fine-tuning of parameter space in order to satisfy the requirements for the large column densities N(sub H) approximately 10(exp 21)/sq cm, unit covering factor, and a small number of clouds along the line of sight. Currently the only way molecular gas can be responsible for the X-ray absorption and still be consistent with our observations is if (1) there is of order one cloud along the line of sight and (2) the optical depth in C-12 1 to 0 is less than 10. In addition, we present a Very Large Array (VLA) image of NGC 4696 which suggests this object is a member of the class of 'amorphous cooling flow radio sources.' The C-12 1 to 0 line is detected in emission in PKS 0634-206, a classical double radio galaxy which is rich in extended optical emission line gas. The estimated molecular gas mass is M(sub mol) approximately 3 x 10(exp 9) solar mass and is much larger than that of the ionized component detected in hydrogen alpha suggesting that the emission-line nebula is radiation bounded.
Document ID
19950036085
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
O'Dea, Christopher P.
(Space Telescope Science Inst. Baltimore, MD, United States)
Baum, Stefi A.
(Space Telescope Science Inst. Baltimore, MD, United States)
Maloney, Philip R.
(Univ. of Colorado, Boulder, CO United States)
Tacconi, Linda J.
(Max-Planck-Institut fuer extraterrestrische Physik Muenchen, Germany)
Sparks, William B.
(Space Telescope Science Inst. Baltimore, MD, United States)
Date Acquired
August 16, 2013
Publication Date
February 20, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 422
Issue: 2
ISSN: 0004-637X
Subject Category
Astronomy
Accession Number
95A67684
Funding Number(s)
CONTRACT_GRANT: NAGW-766
Distribution Limits
Public
Copyright
Other

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