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http://hdl.handle.net/2289/4434| Title: | Optical depth of the universe at radiation-dominated epochs |
| Authors: | Nath, Biman B. Zdziarski, Andrzej |
| Keywords: | cosmic rays dark matter optical thickness radiation distribution red shift compton effect pair production relativistic particles |
| Issue Date: | Oct-1990 |
| Publisher: | American Astronomical Society |
| Citation: | Astrophysical Journal,1990, Vol. 362,p25 |
| Abstract: | If the universe were radiation-dominated at redshifts greater than about 100-1000, e.g., due to the presence of a small fraction of light particles in the dark matter, it would be optically thin in soft gamma-rays up to redshifts of 10,000. This is larger by an order of magnitude than for the matter-dominated universe. X-rays and gamma-rays produced by cosmological high-energy processes are thus potentially observable up to z of about 10,000. Analytical formulas are derived for the optical depths of radiation-dominated universe due to photoionization, Compton scattering, photon-matter pair production, photon-photon scattering, and photon-photon pair production, in interactions with the cosmic thermal background and baryonic matter. |
| Description: | Restricted Access. |
| URI: | http://hdl.handle.net/2289/4434 |
| ISSN: | 0004-637X 1538-4357 (Online) |
| Alternative Location: | http://adsabs.harvard.edu/abs/1990ApJ...362...25N http://dx.doi.org/10.1086/169239 |
| Copyright: | 1990 The American Astronomical Society |
| Appears in Collections: | Research Papers (A&A) |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 1990_ApJ_V362_p25.pdf Restricted Access | Restricted Access | 124.29 kB | Adobe PDF | View/Open Request a copy |
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