Panchromatic Hubble Andromeda Treasury. XIV. The Period-Age Relationship of Cepheid Variables in M31 Star Clusters
Abstract
We present a sample of 11 M31 Cepheids in stellar clusters, derived from the overlap of the Panchromatic Hubble Andromeda Treasury cluster catalog and the Pan-STARRS1 (PS1) disk Cepheid catalog. After identifying the PS1 Cepheids in the Hubble Space Telescope (HST) catalog, we calibrate the PS1 mean magnitudes using the higher resolution HST photometry, revealing up to 1 mag offsets due to crowding effects in the ground-based catalog. We measure ages of the clusters by performing single-age stellar population fits to their color-magnitude diagrams excluding their Cepheids. From these cluster age measurements, we derive an empirical period-age relation which agrees well with the existing literature values. By confirming this relation for M31 Cepheids, we justify its application in high-precision pointwise age estimation across M31.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 2015
- DOI:
- 10.1088/0004-637X/813/1/31
- arXiv:
- arXiv:1509.04791
- Bibcode:
- 2015ApJ...813...31S
- Keywords:
-
- galaxies: individual: M31;
- galaxies: star clusters: general;
- stars: variables: Cepheids;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 14 pages, 16 figures, accepted by ApJ