Abstract Details

Name: Shishir Sankhyayan
Affiliation: National Centre for Radio Astrophysics
Conference ID: ASI2021_322
Title : Optical Identification and Radio Source Counts in the Saraswati Supercluster Region
Authors and Co-Authors : Shishir Sankhyayan (NCRA, India), Ruta Kale (NCRA, India), Joydeep Bagchi (IUCAA, India), Pratik Dabhade (Leiden University, Netherlands and IUCAA, India), C.H. Ishwara-Chandra (NCRA, India), Luis Ho (KIAA, China); Huib Intema (Leiden University, Netherlands), Thorat, Kshitij Thorat (University of Pretoria, South Africa), Wendy Williams (Leiden University, Netherlands), Srikrishna Sekhar (IDIA, South Africa)
Abstract Type : Oral
Abstract Category : Extragalactic Astronomy
Abstract : Saraswati, with a mass of ~ 2 X 10^16 M_sun and size ~ 200 Mpc at redshift ~ 0.28 containing at least 43 clusters, is one of the most massive superclusters discovered in the Universe. Supercluster environments are hard to study due to the rarity of such structures in the Universe. The nearest most well known supercluster is the nearby Shapley supercluster (z ~ 0.04) that has provided first insights on such environments. As all structures, superclusters too have evolved through redshifts and a higher redshift analogue of the Shapley, which is Saraswati, will be an ideal laboratory to study and compare such environments. For this purpose, we have been observing the Saraswati supercluster through uGMRT at 402 MHz in phases under the project – Galaxy Evolution and Magnetization of the Saraswati Supercluster (GEMSS). This is the first deep radio observation of this supercluster reaching an rms noise value of ~ 40 microJy/beam. Here, we present the optical identification and source counts of radio sources of the first phase of GEMSS covering a sky area of ~ 6 deg^2. We have identified ~ 5000 radio sources in our observations and cross-matched them using the galaxy and QSO data available in the Sloan Digital Sky Survey (SDSS) and cluster data available in WHL cluster catalog. Our study of the full observation of the Saraswati supercluster will explore if the supercluster environment plays any role in governing the physical properties of galaxies and clusters and their evolution or not at an intermediate redshift of z ~ 0.3.