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 ofz = 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 × 1015M⊙, were the first objects to separate out of the Hubble expansion. The sensitivity of our experiment rules out the existence of these condensates atz = 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.
Volume 40 | Issue 3
Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.