A Hubble Space Telescope Catalog of 449 Galaxies Seen Through the Disk of M31

TL;DR

This paper presents a catalog of 449 galaxies observed through M31's disk using Hubble Space Telescope images, including their positions, magnitudes, and sizes, while discussing challenges posed by dust extinction.

Contribution

It provides the first comprehensive catalog of background galaxies seen through M31's disk with detailed measurements and analysis of observational challenges.

Findings

Catalog includes 449 galaxies with positional and photometric data.

Dust extinction significantly affects the interpretation of galaxy observations.

The study highlights difficulties in analyzing background galaxies through dusty galactic disks.

Abstract

From inspection of 30 Hubble Space Telescope ACS images of M31, we provide a catalog of 449 galaxies seen through the spiral disk. Measurements of the positions of the galaxies, their integrated magnitudes in two colors and their sizes, determined from isophotometry, are included in the catalog. We discuss the many difficulties of interpreting these data in terms of the effects of intervening extinction by dust in the disk