The white dwarf cooling sequence of the globular cluster Messier 4

被引：195

作者：

Hansen, BMS

Brewer, J

Fahlman, GG

Gibson, BK

Ibata, R

Limongi, M

Rich, RM

Richer, HB

Shara, MM

Stetson, PB

机构：

[1] Univ Calif Los Angeles, Div Astron, Los Angeles, CA 90095 USA

[2] Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA

[3] Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z4, Canada

[4] Canada France Hawaii Telescope Corp, Kamuela, HI 96743 USA

[5] Swinburne Univ Technol, Ctr Astrophys Supercomp, Hawthorn, Vic 3122, Australia

[6] Observ Strasbourg, F-67000 Strasbourg, France

[7] Osserv Astron Roma, I-00040 Monte Porzio Catone, Italy

[8] Amer Museum Nat Hist, Dept Astrophys, Div Phys Sci, New York, NY 10024 USA

[9] Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7, Canada

来源：

ASTROPHYSICAL JOURNAL | 2002年 / 574卷 / 02期

基金：

美国国家航空航天局; 加拿大自然科学与工程研究理事会; 澳大利亚研究理事会;

关键词：

Galaxy : halo; globular clusters : individual (M4); stars : luminosity function; mass function; stars : Population II; white dwarfs;

D O I：

10.1086/342528

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of Vsimilar to30 and Isimilar to28. The white dwarf luminosity function rises sharply for I>25.5, consistent with the behavior expected for a burst population. The white dwarfs of M4 extend to approximately 2.5 mag fainter than the peak of the local Galactic disk white dwarf luminosity function. This demonstrates a clear and significant age difference between the Galactic disk and the halo globular cluster M4. Using the same standard white dwarf models to fit each luminosity function yields ages 7.3+/-1.5 of Gyr for the disk and 12.7+/-0.7 Gyr for M4 (2 sigma statistical errors).

引用

页码：L155 / L158

页数：4

共 46 条

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