Dwarf Galaxies in the Halo of NGC 891

TL;DR

This study surveys the region around NGC 891, discovering 7 new dwarf galaxies, many of which are gas-poor and show signs of disruption, expanding understanding of galaxy populations in this area.

Contribution

The paper presents a new survey identifying 7 dwarf galaxies near NGC 891, many of which are previously uncataloged and show signs of interaction or disruption.

Findings

Discovered 7 new dwarf galaxies, many previously uncataloged.

Most dwarfs are gas-poor and show signs of disruption.

The survey roughly doubles the known members of Abell 347 cluster.

Abstract

We report the results of a survey of the region within 40 arcmin of NGC 891, a nearby nearly perfectly edge-on spiral galaxy. Candidate "non-stars" with diameters greater than 15 arcsec were selected from the GSC 2.3.2 catalog and cross-comparison of observations in several bands using archived \galex, DSS2, WISE, and 2MASS images identified contaminating stars, artifacts and background galaxies, all of which were excluded. The resulting 71 galaxies, many of which were previously uncataloged, comprise a size limited survey of the region. A majority of the galaxies are in the background of NGC 891 and are for the most part members of the Abell 347 cluster at a distance of about 75 \Mpc. The new finds approximately double the known membership of Abell 347, previously thought to be relatively sparse. We identify a total of 7 dwarf galaxies, most of which are new discoveries. The newly discovered dwarf galaxies are dim and gas-poor and may be associated with the previously observed arcs of RGB halo stars in the halo and the prominent HI filament and the lopsided features in the disk of NGC 891. Several of the dwarfs show signs of disruption, consistent with being remnants of an ancient collision.