The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER). IV. Star Cluster Catalog

TL;DR

This paper presents a new catalog of 1214 star clusters in the Triangulum Galaxy (M33), including many newly identified clusters, with detailed photometry and property estimates, based on Hubble Space Telescope data and citizen science classifications.

Contribution

It provides the first extensive star cluster catalog for M33 using Hubble data, incorporating citizen science classifications and comprehensive photometric analysis.

Findings

68% of clusters are newly identified.

Catalog includes multi-band photometry and cluster property fits.

Completeness limit is approximately 1500 solar masses at 100 Myr.

Abstract

We construct a catalog of star clusters from Hubble Space Telescope images of the inner disk of the Triangulum Galaxy (M33) using image classifications collected by the Local Group Cluster Search, a citizen science project hosted on the Zooniverse platform. We identify 1214 star clusters within the Hubble Space Telescope imaging footprint of the Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) survey. Comparing this catalog to existing compilations in the literature, 68% of the clusters are newly identified. The final catalog includes multi-band aperture photometry and fits for cluster properties via integrated light SED fitting. The cluster catalog's 50% completeness limit is ~1500 solar masses at an age of 100 Myr, as derived from comprehensive synthetic cluster tests.