PROPERTIES OF M31. III. CANDIDATE BEAT CEPHEIDS FROM PS1 PANDROMEDA DATA AND THEIR IMPLICATION ON METALLICITY GRADIENT

Journal Article · Fri Nov 01 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/777/1/35· OSTI ID:22270675

Lee, C. -H.; Kodric, M.; Seitz, S.; Riffeser, A.; Koppenhoefer, J.; Bender, R.; Hopp, U.; Gössl, C.; Snigula, J. ^[1]; Burgett, W. S.; Chambers, K. C.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R. -P.; Tonry, J. L.; Wainscoat, R. J. ^[2]; Price, P. A. ^[3]

---

1. University Observatory Munich, Scheinerstrasse 1, D-81679 Munich (Germany)
2. Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)
3. Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

We present a sample of M31 beat Cepheids from the Pan-STARRS 1 PAndromeda campaign. By analyzing 3 years of PAndromeda data, we identify 17 beat Cepheids, spreading over a galactocentric distance of 10-16 kpc. Since the relation between the fundamental mode period and the ratio of the fundamental to the first overtone period places a tight constraint on metallicity, we are able to derive the metallicity at the position of the beat Cepheids using the relations from the model of Buchler. Our metallicity estimates show sub-solar values within 15 kpc, similar to the metallicities from H II regions. We then use the metallicity estimates to calculate the metallicity gradient of the M31 disk, which we find to be closer to the metallicity gradient derived from planetary nebula than the metallicity gradient from H II regions.

• OSTI ID: 22270675
• Journal Information: Astrophysical Journal, Vol. 777, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTRONOMY
ASTROPHYSICS
CEPHEIDS
DISTANCE
GALAXIES
H2 REGIONS
LIMITING VALUES
METALS
PLANETARY NEBULAE