Compact Groups of Galaxies in Sloan Digital Sky Survey and LAMOST Spectral Survey: I. The Catalogs

TL;DR

This paper presents the creation of the largest and most complete catalog of compact galaxy groups by combining photometric and spectroscopic data from SDSS, LAMOST, and GAMA surveys, enabling advanced studies of galaxy evolution.

Contribution

It introduces a novel combined selection method that reduces biases and produces the largest, most comprehensive catalog of compact galaxy groups to date.

Findings

Catalog includes 6,144 confirmed CGs and 8,022 candidates.

Enhanced completeness and reduced bias compared to previous catalogs.

Facilitates detailed studies of galaxy interactions and evolution.

Abstract

A compact group (CG) is a kind of special galaxy system where the galaxy members are separated at the distances of the order of galaxy size. The strong interaction between the galaxy members makes CGs ideal labs for studying the environmental effects on galaxy evolution. The traditional photometric selection algorithm biases against the CG candidates at low redshifts, while the spectroscopic identification technique is affected by the spectroscopic incompleteness of sample galaxies and typically biases against the high redshift candidates. In this study, we combine these two methods and select CGs in the main galaxy sample of the Sloan Digital Sky Survey, where we also have taken the advantages of the complementary redshift measurements from the LAMOST spectral and GAMA surveys. We have obtained the largest and most complete CG samples to date. Our samples include 6,144 CGs and 8,022 CG candidates, which are unique in the studies of the nature of the CGs and the evolution of the galaxies inside.