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Compton broadening effect on spectral line formation

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Abstract

We have investigated the effects of Compton broadening due to electron scattering in an expanding stellar atmospheres. The line transfer equation is solved by including the second approximation of Edmonds (Astrophys. J. 119:58, 1954) which is due to Compton broadening and obtained the line profiles in (1) plane parallel (PP) (2) spherical (SS) atmospheres. The effect on spectral line formation is studied for different parameters like (a) optical depths (b) densities (c) frequencies (d) temperatures (e) thickness of the atmosphere and (f) expanding velocities. Various combination of the above parameters are used in computing the line profiles observed at infinity.

Line profiles are compared for the above said parameters. It is noticed that the expansion of the gases in the atmosphere produces P-Cygni type profiles and at higher optical depths the line profiles change from emission to absorption with their line centers shifting to blue side in the expanding atmospheres.

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Acknowledgements

Authors would like to thank Dr. Christina Birde for correcting the entire manuscript.

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Authors and Affiliations

  1. Dollar Scheme, # 57, 4th Cross, 36 Main, BTM 1st Stage, Madiwala, Bangalore, 560068, India

    A. Peraiah

  2. Indian Institute of Astro Physics, Koramangala, Bangalore, 560034, India

    M. Srinivasa Rao

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  1. A. Peraiah
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  2. M. Srinivasa Rao
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Correspondence to M. Srinivasa Rao.

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Peraiah, A., Srinivasa Rao, M. Compton broadening effect on spectral line formation. Astrophys Space Sci 343, 195–211 (2013). https://doi.org/10.1007/s10509-012-1233-0

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