A2125 and Its Environs: Evidence for an X-Ray-Emitting Hierarchical Superstructure
Abstract
Based on a deep ROSAT/PSPC observation, we reveal an elongated complex of extended X-ray-emitting objects in and around the galaxy cluster A2125. Multicolor optical imaging of galaxies in the field suggests that this complex represents a hierarchical superstructure spanning ~11 h-150 Mpc at the redshift ~0.247. The multiple peak X-ray morphology and large blue galaxy fraction of A2125 indicate that the cluster is undergoing a coalescence of subunits. The superstructure contains two additional clusters, projected at distances of only 3 and 4.3 h-150 Mpc from A2125. The most interesting feature is, however, the low surface brightness X-ray emission from a moderate galaxy concentration away from individual clusters. The emission likely arises in a hot (~107 K) intergalactic medium, as predicted in N-body/hydro simulations of structure formation.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 1997
- DOI:
- 10.1086/310859
- arXiv:
- arXiv:astro-ph/9702018
- Bibcode:
- 1997ApJ...487L..13W
- Keywords:
-
- COSMOLOGY: OBSERVATIONS;
- COSMOLOGY: LARGE-SCALE STRUCTURE OF UNIVERSE;
- GALAXIES: CLUSTERS: GENERAL;
- GALAXIES: CLUSTERS: INDIVIDUAL ALPHANUMERIC: A2125;
- X-RAYS: GENERAL;
- Cosmology: Observations;
- Galaxies: Clusters: General-- Galaxies: Clusters: Individual: Alphanumeric: A2125;
- Cosmology: Large-Scale Structure of Universe;
- X-Rays: General;
- Astrophysics
- E-Print:
- Submitted to The Astrophysical Journal Letters, 13 pages, plus 6 figures in the jpeg or GIF format. Black &