A Method for Separating the Physics from the Astrophysics of High-Redshift 21 Centimeter Fluctuations
View/ Open
Author
Barkana, Rennan
Loeb, Abraham
Published Version
https://doi.org/10.1086/430599Metadata
Show full item recordCitation
Barkana, Rennan, and Abraham Loeb. 2005. “A Method for Separating the Physics from the Astrophysics of High-Redshift 21 Centimeter Fluctuations.” The Astrophysical Journal 624 (2): L65–68. https://doi.org/10.1086/430599.Abstract
Fluctuations in the 21 cm brightness from cosmic hydrogen at redshifts z ≳ 6 have their source in the primordial density perturbations from inflation, as well as the radiation from galaxies. We propose a method to separate these components based on the angular dependence of the 21 cm fluctuation power spectrum. Peculiar velocities increase the power spectrum by a factor of ∼ 2 compared with density fluctuations alone and introduce an angular dependence in Fourier space. The resulting angular structure relative to the line of sight facilitates a simple separation of the power spectrum into several components, permitting an unambiguous determination of the primordial power spectrum of density fluctuations, and of the detailed properties of all astrophysical sources of 21 cm fluctuations. We also demonstrate that angular multipoles are not useful for measuring large-scale power, and thus, theoretical predictions should focus on the three-dimensional power spectrum of 21 cm fluctuations.Terms of Use
This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAACitable link to this page
http://nrs.harvard.edu/urn-3:HUL.InstRepos:41393417
Collections
- FAS Scholarly Articles [17828]
Contact administrator regarding this item (to report mistakes or request changes)