AstroSat/UVIT Cluster Photometry in the Northern Disk of M31

Abstract

The Andromeda Galaxy (M31) is an object of ongoing study with the Ultraviolet Imaging Telescope (UVIT) on AstroSat. UVIT FUV and NUV photometry is carried out here for a set of 239 clusters in the NE disk and bulge of M31 which overlap with the HST/PHAT survey. Padova stellar models were applied to derive ages, masses, metallicities and extinctions for 170 clusters. The ages show a narrow peak at $\sim$4 Myr and a broad peak around 100 Myr. log(Z/Z${}_{\odot }$) values are mostly between $-0.3$ and $+0.3$. The 7 clusters in the bulge are low metallicity and high mass. Most clusters are in the spiral arms and have metallicities in the range noted above. The youngest clusters are mostly high metallicity and are concentrated along the brightest parts of the spiral arms. The UVIT FUV and NUV data are sensitive to young stars and detect a new metal rich peak in star formation in the disk at age $\sim 4$ Myr.

19 pages, 10 figures

References in corpus (5)

• An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
• The Panchromatic Hubble Andromeda Treasury X. Ultraviolet to Infrared Photometry of 117 Million Equidistant Stars
• Additional Calibration of the Ultra-Violet Imaging Telescope on board AstroSat
• PHAT Stellar Cluster Survey. II. Andromeda Project Cluster Catalog
• Star Formation Histories from SEDs and CMDs Agree: Evidence for Synchronized Star Formation in Local Volume Dwarf Galaxies over the Past 3 Gyr

Cited by in corpus (3)

• Field blue straggler stars: Discovery of white dwarf companions to blue metal-poor stars using UVIT/AstroSat
• The Complex Structure of the Bulge of M31
• Discovery of 20 UV Emitting SNRs in M31 with UVIT