منابع مشابه
The First Light seen in the redshifted 21–cm radiation
We show how the investigation of the redshifted 21–cm radiation can give insight into the development of structures in the early universe (at redshifts z > 5). In particular we investigate: the epoch of the first light; the fluctuations in the redshifted 21–cm emission induced by the density inhomogeneities in CDM dominated universes; the emission and absorption shells that are generated around...
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The first stars and quasars are known sources of hard ionizing radiation in the first billion years of the Universe. We examine the joint effects of X-rays and hard ultraviolet (UV) radiation from such first-light sources on the hydrogen and helium reionization of the intergalactic medium (IGM) at early times, and the associated heating. We study the growth and evolution of individual H II, He ...
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The distance of the Virgo cluster is derived in the B band from the 21 cm-line width-absolute magnitude relation. The latter is calibrated using 18 spirals with Cepheid distances mainly from HST. The calibration is applied to a complete sample of non-peculiar spirals with i > 45◦ and lying within the optical (n=49) or X-ray (n=35) contour of the cluster, resulting in a mean cluster distance of ...
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15 صفحه اولLight-cone effect on the reionization 21-cm power spectrum
Observations of redshifted 21-cm radiation from neutral hydrogen during the epoch of reionization are considered to constitute the most promising tool to probe that epoch. One of the major goals of the first generation of low-frequency radio telescopes is to measure the 3D 21-cm power spectrum. However, the 21-cm signal could evolve substantially along the lineof-sight (LOS) direction of an obs...
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ژورنال
عنوان ژورنال: Publications of the Astronomical Society of the Pacific
سال: 1964
ISSN: 0004-6280,1538-3873
DOI: 10.1086/128112