The Hubble Arp Galaxy Survey ("HAGS")

The Hubble Arp Galaxy Survey is an atlas of 216 new optical F606W images of systems drawn from the Arp (1966) and Arp & Madore (1987) catalogs of peculiar galaxies. The images were collected through a "gap-filler" program (SNAP-15446; PI: Dalcanton) that used shorter than average orbits, drawing targets from the Arp catalogs that lacked imaging and were well-matched to ACS/WFC's large field of view.

The resulting galaxy images display rich morphologies, revealing a variety of massive stars, HII regions, stellar clusters, dust lanes, tidal tails, backlit galaxies, and occasional chance superpositions. The atlas images provide a superb starting point for more detailed studies with high-resolution imaging in other wavelengths, and spectroscopy to track kinematics and the interstellar medium (ISM). Areas of obvious scientific relevance include feedback and star formation in merging and interacting galaxies, resolved stellar populations at the extremes of stellar density, the properties of young massive stars and stellar clusters, the physics of the cold ISM and dust, and stellar and gas dynamics.

This repository includes the reduced images and catalogs of point-source photometry presented in Dalcanton et al. 2025. A shorter atlas-form PDF of the images is available on Zenodo at DOI:10.5281/zenodo.16778896.