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http://hdl.handle.net/2289/4029| Title: | Carbon ionization states and the cosmic far-UV background with He II absorption |
| Authors: | Vasiliev, Evgenii O. Sethi, S.K. Nath, Biman B. |
| Keywords: | cosmology: theory diffuse radiation intergalactic medium quasars: general |
| Issue Date: | 28-Jul-2010 |
| Publisher: | IOP Publishing Ltd. |
| Citation: | Astrophysical Journal, 2010, Vol. 719, p1343 |
| Abstract: | We constrain the spectrum of the cosmic ultraviolet background radiation by fitting the observed abundance ratios of carbon ions at z ~ 2-3 with those expected from different models of the background radiation. We use the recently calculated modulation of the background radiation between 3 and 4 Ryd due to resonant line absorption by intergalactic He II and determine the ratios of C III to C IV expected at these redshifts, as functions of metallicity, gas density, and temperature. Our analysis of the observed ratios shows that "delayed reionization" models, which assume a large fraction of He II at z ~ 3, are not favored by data. Our results suggest that He II reionization was inhomogeneous, consistent with the predictions from recent simulations. |
| Description: | Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations) |
| URI: | http://hdl.handle.net/2289/4029 |
| ISSN: | 1538-4357-(Online) 0004-637X |
| Alternative Location: | http://adsabs.harvard.edu/abs/2010ApJ...719.1343V http://arxiv.org/abs/1006.4985 http://dx.doi.org/10.1088/0004-637X/719/2/1343 |
| Copyright: | 2010 IOP Publishing for the American Astronomical Society |
| Appears in Collections: | Research Papers (A&A) |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 2010_APJ_719_2_1343.pdf Restricted Access | Restricted Access | 433.21 kB | Adobe PDF | View/Open Request a copy |
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