Journal
ASTROPHYSICAL JOURNAL LETTERS
Volume 813, Issue 2, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.1088/2041-8205/813/2/L38
Keywords
dark ages, reionization, first stars; intergalactic medium; quasars: absorption lines
Categories
Funding
- NSF [AST1312724]
- NASA [ATP-NNX14AB57G]
- Division Of Astronomical Sciences
- Direct For Mathematical & Physical Scien [1312991, 1312724] Funding Source: National Science Foundation
Ask authors/readers for more resources
Recent observations of the Ly alpha forest show large-scale spatial variations in the intergalactic Ly alpha opacity that grow rapidly with redshift at z > 5, far in excess of expectations from empirically motivated models. Previous studies have attempted to explain this excess with spatial fluctuations in the ionizing background, but found that this required either extremely rare sources or problematically low values for the mean free path of ionizing photons. Here we report that much-or potentially all-of the observed excess likely arises from residual spatial variations in temperature that are an inevitable byproduct of a patchy and extended reionization process. The amplitude of opacity fluctuations generated in this way depends on the timing and duration of reionization. If the entire excess is due to temperature variations alone, the observed fluctuation amplitude favors a late-ending but extended reionization process that was roughly half complete by z similar to 9 and that ended at z similar to 6. In this scenario, the highest opacities occur in regions that reionized earliest, since they have had the most time to cool, while the lowest opacities occur in the warmer regions that reionized most recently. This correspondence potentially opens a new observational window into patchy reionization.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available