Bot, Caroline and Helou, George and Latter, William B. and Puget, Jérémie and Schneider, Stephen and Terzian, Yervant (2009) A Search for Dust Emission in the Leo Intergalactic Cloud. Astronomical Journal, 138 (2). pp. 452-458. ISSN 0004-6256 http://resolver.caltech.edu/CaltechAUTHORS:20090810-084634970
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We present a search for infrared dust emission associated with the Leo cloud, a large intergalactic cloud in the M96 group. Mid-infrared and far-infrared images were obtained with the InfraRed Array Camera and the Multiband Imaging Photometer for Spitzer on the Spitzer Space Telescope. Our analysis of these maps is done at each wavelength relative to the H I spatial distribution. We observe a probable detection at 8 μm and a marginal detection at 24 μm associated with the highest H I column densities in the cloud. At 70 and 160 μm, upper limits on the dust emission are deduced. The level of the detection is low so that the possibility of a fortuitous cirrus clump or of an overdensity of extragalactic sources along the line of sight cannot be excluded. If this detection is confirmed, the quantities of dust inferred imply a dust-to-gas ratio in the intergalactic cloud up to a few times solar but no less than 1/20 solar. A confirmed detection would therefore exclude the possibility that the intergalactic cloud has a primordial origin. Instead, this large intergalactic cloud could therefore have been formed through interactions between galaxies in the group.
|Additional Information:||© 2009. The American Astronomical Society. Print publication: Issue 2 (2009 August). Received 2008 November 10, accepted for publication 2009 May 17 Published 2009 June 29. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. We would like to thank M. Fouesneau and D. Thilker for their help on the estimate of the UV radiation field from the star-forming region with evolutionary synthesis models.|
|Subject Keywords:||infrared: ISM; intergalactic medium; ISM: clouds; ISM: individual (Leo cloud)|
|Official Citation:||A Search for Dust Emission in the Leo Intergalactic Cloud Caroline Bot, George Helou, William B. Latter, Jérémie Puget, Stephen Schneider, and Yervant Terzian 2009 The Astronomical Journal 138 452-458 doi: 10.1088/0004-6256/138/2/452|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||01 Sep 2009 23:26|
|Last Modified:||26 Dec 2012 11:10|
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