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350 Micron Observations of Local Luminous Infrared Galaxies and the Temperature Dependence of the Emissivity Index

M. Yang·T. G. Phillips
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Abstract

We report 350micron observations of 18 nearby luminous infrared galaxies (LIRGs), using the Submillimeter High Angular Resolution Camera II (SHARC-II) mounted on the Caltech Submillimeter Observatory (CSO) 10.4m telescope. Combining our 350micron flux measurements with the existing far-infrared (far-IR) and submillimeter (submm) data, we fit a single-temperature model to the spectral energy distributions (SEDs), and find the dust temperatures, emissivity indices and far-IR luminosities having sample medians of Td = 39.4+-7.9K, beta = 1.6+-0.3 and log(Lfir/Lsolar) = 11.2+-0.6. An empirical inverse Td-beta correlation, best described by Td = 9.86E9^(1/(4.63 + beta)), is established for the local LIRG sample, which we argue can be explained by the intrinsic interdependence between the dust temperature and grain emissivity index as physical parameters, as well as variations in grain properties in the the interstellar medium (ISM).

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M. Yang, T. G. Phillips. 2007-02-18. 350 Micron Observations of Local Luminous Infrared Galaxies and the Temperature Dependence of the Emissivity Index. https://doi.org/10.1086/514810

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