An observational constraint on the existence of proto-superclusters at z = 3.3

Subrahmanyan, Ravi ; Swarup, G. (1990) An observational constraint on the existence of proto-superclusters at z = 3.3 Journal of Astrophysics and Astronomy, 11 (2). pp. 237-253. ISSN 0250-6335

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Observations have been conducted using the Ooty Radio Telescope in order to place constraints on the evolutionary scenario leading to the formation of the present day superclusters. The experiment attempted to detect 21 cm emission from massive neutral hydrogen condensates at a redshift of z = 3.3. In an Einstein de-Sitter universe with baryon density Ω = 0.05, about ten condensates were expected in the volume surveyed if superclusters, having H I masses ≃5 × 1015 M☉, were the first objects to separate out of the Hubble expansion. The sensitivity of our experiment rules out the existence of these condensates at z = 3.3 unless their lifetimes are less than one-tenth the dispersion in their epoch of formation or the proto-superclusters subtend angles greater than 6 arcmin. The result indicates that superclusters form at z > 3.3 if indeed they were the first objects to condense out of the Hubble flow.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Clusters of Galaxies; Formation HI Observations HI Regions; Cosmological Protoclusters Superclusters; Formation
ID Code:114347
Deposited On:22 May 2018 06:33
Last Modified:22 May 2018 06:33

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