BOSS Great Wall: morphology, luminosity, and mass

¹ Tartu Observatory, Observatooriumi 1, 61602 Tõravere, Estonia
e-mail: maret.einasto@to.ee
² Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Väisäläntie 20, 21500 Piikkiö, Finland
³ Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
⁴ Institute of Physics, University of Tartu, W.Ostwaldi 1, 50411 Tartu, Estonia
⁵ Department of Physics and Astronomy, The University of Utah, 115 South 1400 East, Salt Lake City, UT 84112, USA
⁶ Instituto de Astrofísica de Canarias, 38200 La Laguna, Tenerife, Spain
⁷ Universidad de La Laguna, Dept. Astrofísica, 38206 La Laguna, Tenerife, Spain
⁸ ICG-University of Portsmouth, Dennis Sciama Building, Burnaby Road, PO1 3FX, Portsmouth, UK

Received: 13 June 2016
Accepted: 17 March 2017

Abstract

Context. Galaxy superclusters are the largest systems in the Universe that can give us information about the formation and evolution of the cosmic web.

Aims. We study the morphology of the superclusters from the BOSS Great Wall (BGW), a recently discovered very rich supercluster complex at the redshift z = 0.47.

Methods. We have employed the Minkowski functionals to quantify supercluster morphology. We calculate supercluster luminosities and masses using two methods. Firstly, we used data about the luminosities and stellar masses of high stellar mass galaxies with log (M_∗/h^-1M_⊙) ≥ 11.3. Secondly, we applied a scaling relation that combines morphological and physical parameters of superclusters to obtain supercluster luminosities, and obtained supercluster masses using the mass-to-light ratios found for local rich superclusters.

Results. The BGW superclusters are very elongated systems, with shape parameter values of less than 0.2. This value is lower than that found for the most elongated local superclusters. The values of the fourth Minkowski functional V₃ for the richer BGW superclusters (V₃ = 7 and 10) show that they have a complicated and rich inner structure. We identify two Planck SZ clusters in the BGW superclusters, one in the richest BGW supercluster, and another in one of the poor BGW superclusters. The luminosities of the BGW superclusters are in the range of 1−8 × 10¹³h^-2L_⊙, and masses in the range of 0.4−2.1 × 10¹⁶h^-1M_⊙. Supercluster luminosities and masses obtained with two methods agree well.

Conclusions. The BGW is a complex of massive, luminous and large superclusters with very elongated shape. The search and detailed study, including the morphology analysis of the richest superclusters and their complexes from observations and simulations can help us to understand formation and evolution of the cosmic web.