Radio spectra of several ultraluminous IRAS galaxies
A sample of IRAS galaxies with infrared luminosities as high as 10 11.8 to 10 12.8 L⊙ were observed using the Australia Telescope Compact Array (ATCA) at 8.6, 4.8, 2.4 and 1.4 GHz. 4 galaxies in the sample are found to have steep spectra at high frequency and their flux densities decrease at low fre...
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Published in | Chinese astronomy and astrophysics Vol. 26; no. 2; pp. 158 - 163 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
01.04.2002
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Subjects | |
Online Access | Get full text |
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Summary: | A sample of IRAS galaxies with infrared luminosities as high as 10
11.8 to 10
12.8
L⊙ were observed using the Australia Telescope Compact Array (ATCA) at 8.6, 4.8, 2.4 and 1.4 GHz. 4 galaxies in the sample are found to have steep spectra at high frequency and their flux densities decrease at low frequency, showing a peak-like spectral pattern with the peak flux at several GHz. Two possible mechanisms, synchrotron self-absorption and free-free absorption, for the turning-over in the low-frequency side are discussed. From the analysis of the spectra of the IRAS sources, 00199-7426, 02587-6336, 07020-5423 and 21547-5823, we conclude that free-free absorption may be the cause for the low-frequency turnover. By model fitting to the observations several physical parameters of the sources are obtained. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0275-1062 1879-128X |
DOI: | 10.1016/S0275-1062(02)00053-X |