Saraswati: An Extremely Massive ~ 200 Megaparsec Scale Supercluster

Understand

Here we report the discovery of an extremely massive and large supercluster (called Saraswati) found in the Stripe 82 region of SDSS.

• This supercluster is a major concentration of galaxies and galaxy clusters, forming a wall-like structure spanning at least 200 Mpc across at the redshift $z \approx 0.3$.
• This enormous structure is surrounded by a network of galaxy filaments, clusters, and large, $\sim40 - 170$ Mpc diameter, voids.
• The mean density contrast $\delta$ (relative to the background matter density of the universe) of Saraswati is $\gtrsim 1.62$ and the main body of the supercluster comprises at least 43 massive galaxy clusters (mean $z = 0.28$) with a total mass of $\sim 2 \times 10^{16} M_{\odot}$.