The QUEST RR Lyrae Survey: Confirmation of the Clump at 50 kpc and Other Over-Densities in the Outer Halo
| Autor: | Ignacio Ferrin, G. Magris, F. Della Prugna, Jae Il Shin, R. Pacheco, R. K. Honeycutt, Ge. Sánchez, M. Gebhard, Sabatino Sofia, K. Vieira, Nancy Ellman, W. F. van Altena, B. E. Schaefer, C. Abad, Charles D. Bailyn, Terrence M. Girard, B. Vicente, H. Schenner, Gustavo Bruzual, Paolo De Coppi, David Herrera, A. K. Vivas, D. Rabinowitz, P. Andrews, Jonay I. González Hernández, Cesar Briceno, s. Muffson, C. Baltay, A. Rengstorf, J. A. Snyder, J. Stock, R. Zinn, J. Musser, J. Mateu, Gu. Sánchez, A. Bongiovanni |
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| Rok vydání: | 2001 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences Astrophysics (astro-ph) FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Sagittarius Stream Astrophysics RR Lyrae variable Light curve 01 natural sciences Galaxy Stars Space and Planetary Science Globular cluster 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Halo Right ascension 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences |
| DOI: | 10.48550/arxiv.astro-ph/0105135 |
| Popis: | We have measured the periods and light curves of 148 RR Lyrae variables from V=13.5 to 19.7 from the first 100 sq. degrees of the QUEST RR Lyrae survey. Approximately 55% of these stars belong to the clump of stars detected earlier by the Sloan Digital Sky Survey. According to our measurements, this feature has ~10 times the background density of halo stars, spans at least 37.5 deg by 3.5 deg in right ascension and declination (>=30 by >=3 kpc), lies ~50 kpc from the Sun, and has a depth along the line of sight of ~5 kpc (1 sigma). These properties are consistent with the recent models that suggest it is a tidal stream from the Sgr dSph galaxy. The mean period of the type ab variables, 0.58 d, is also consistent. In addition, we have found two smaller over-densities in the halo, one of which may be related to the globular cluster Pal 5. 12 pages (including 4 figures). Accepted for publication in the ApJ Letters |
| Databáze: | OpenAIRE |
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