Short-Period Variable Stars in the M31 Halo
| العنوان: | Short-Period Variable Stars in the M31 Halo |
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| المؤلفون: | A. Saha, Frank Thim, Andrew E. Dolphin, John G. Hoessel, Evan D. Skillman, Edward W. Olszewski, John S. Gallagher |
| المصدر: | The Astronomical Journal. 127:875-896 |
| بيانات النشر: | American Astronomical Society, 2004. |
| سنة النشر: | 2004 |
| مصطلحات موضوعية: | Physics, 010504 meteorology & atmospheric sciences, Period (periodic table), Metallicity, Milky Way, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy, Stars, Space and Planetary Science, 0103 physical sciences, Magnitude (astronomy), Astrophysics::Solar and Stellar Astrophysics, Halo, Variable star, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences |
| الوصف: | We report the findings of a new search for RR Lyraes in an M31 halo field located 40 arcminutes from the nucleus of the galaxy along the minor axis. We detected 37 variable stars, of which 24 are classified as RR Lyraes and the others are ambiguous. Estimating a completeness fraction of ~24%, we calculate that there are approximately 100 RR Lyraes in the field, which is consistent with what is expected from deep HST color-magnitude diagrams. We calculate a mean magnitude of g=25.15+/ 0.03, which we interpret to mean that the mean metallicity of RR Lyraes is significantly lower than that of the M31 halo as a whole. The presence of ancient, metal-poor stars opens the possibility that, initially, the M31 halo appeared much like the Milky Way halo. Comment: 43 pages, 9 figures. Accepted for publication in AJ |
| تدمد: | 1538-3881 0004-6256 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b698bd83e7d62bbbe3e84b5159b75602Test https://doi.org/10.1086/381301Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....b698bd83e7d62bbbe3e84b5159b75602 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15383881 00046256 |
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