Visual Survey of 18020 Objects from the 2MFGC Catalog

TL;DR

This study systematically surveyed 18,020 galaxies from the 2MFGC catalog using infrared and visual imaging to identify and exclude false flat galaxy objects, providing a refined catalog with detailed observations and data.

Contribution

It introduces a comprehensive method for verifying flat galaxy candidates in the 2MFGC catalog through multi-filter imaging, improving catalog accuracy.

Findings

Identified 1,512 true flat galaxies out of 18,020 objects.

Detected 23 duplicated entries in the catalog.

Excluded faint, low surface brightness objects from the flat galaxy list.

Abstract

We conducted a continuous survey of infrared and visual images of 18020 2MFGC galaxies which were selected on an automatic basis from 1.64 mln extended objects of the 2MASS XSC catalog based on the ratio of the infrared axes a/b>=3. This work aims to exclude "false" objects from the list of flat galaxies. Having observed more than 80 thousand images in different filters, we were able to detect 1512 such objects (8.4% of the total number). We found 23 galaxies duplicated in 2MASS, which have two 2MFGC numbers correspondingly, and three flat galaxies which are not included in other catalogs and are located close to three "false" galaxies. Galaxies with magnitudes fainter than K_s =13 mag compose the main part of the excluded objects. They show small angular sizes, low surface brightnesses and concentration ratios. The results of the work in the form of the 2MFGC table with notes are given in the astronomical databases VizieR, NED, HyperLeda.