Abell 2626 and friends: large and small scale structure

TL;DR

This study provides extensive spectroscopic data revealing the complex multi-scale structure around galaxy clusters A2626 and A2637, including substructures and their spatial relationships, refining our understanding of their cosmic environment.

Contribution

The paper presents new spectroscopic observations that significantly expand redshift data, uncover multiple substructures, and clarify the large-scale structure around A2626 and A2637.

Findings

Confirmed four clusters previously identified photometrically.

Discovered six substructures associated with A2626.

Identified a collimated galaxy collection between A2626 and A2637.

Abstract

New MMT/Hectospec spectroscopy centered on the galaxy cluster A2626 and covering a ${\sim} 1.8\,\text{deg}^2$ area out to $z \sim 0.46$ more than doubles the number of galaxy redshifts in this region. The spectra confirm four clusters previously identified photometrically. A2625, which was previously thought to be a close neighbor of A2626, is in fact much more distant. The new data show six substructures associated with A2626 and five more associated with A2637. There is also a highly collimated collection of galaxies and galaxy groups between A2626 and A2637 having at least three and probably four substructures. At larger scales, the A2626--A2637 complex is not connected to the Pegasus--Perseus filament.