The hot stars in orbit around the M31 central supermassive black hole: are they young or old?

被引:15
作者
Demarque, P. [1 ]
Virani, S. [1 ]
机构
[1] Yale Univ, Dept Astron, New Haven, CT 06520 USA
关键词
stars : evolution; galaxies : active; galaxies : individual : M31;
D O I
10.1051/0004-6361:20065921
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Aims. The cluster of hot stars observed in orbit around the central black hole of M 31 has been interpreted as a 200 Myr starburst. The formation of a population of young stars in close proximity to a massive black hole presents a difficult challenge to star formation theory. We point out that in a high stellar density environment, the course of stellar evolution is modified by frequent collisions and mergers. Methods. Blue stragglers, which are the results of mergers in globular clusters, occupy the same position in the color-magnitude diagram as the observed hot stars in M 31. For confirmation, the integrated spectrum of P3 is shown to be compatible with the spectral energy distribution of a blue horizontal branch field star. Results. We suggest an old stellar population of evolved blue horizontal-branch stars and of merger products cannot be ruled out on the basis of the available data. Observations are suggested that would help distinguish between a "young" and "old" stellar population interpretation of the observations.
引用
收藏
页码:651 / 656
页数:6
相关论文
共 53 条
  • [1] The distribution of stars near the supermassive black hole in the Galactic center
    Alexander, T
    [J]. ASTROPHYSICAL JOURNAL, 1999, 527 (02) : 835 - 850
  • [2] Stellar processes near the massive black hole in the Galactic center
    Alexander, T
    [J]. PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 2005, 419 (2-3): : 65 - 142
  • [3] IAC-STAR: A code for synthetic color-magnitude diagram computation
    Aparicio, A
    Gallart, C
    [J]. ASTRONOMICAL JOURNAL, 2004, 128 (03) : 1465 - 1477
  • [4] HST STIS spectroscopy of the triple nucleus of M31:: Two nested disks in keplerian rotation around a supermassive black hole
    Bender, R
    Kormendy, J
    Bower, G
    Green, R
    Thomas, J
    Danks, AC
    Gull, T
    Hutchings, JB
    Joseph, CL
    Kaiser, ME
    Lauer, TR
    Nelson, CH
    Richstone, D
    Weistrop, D
    Woodgate, B
    [J]. ASTROPHYSICAL JOURNAL, 2005, 631 (01) : 280 - 300
  • [5] BIALYN CD, 1995, ARA A, V33, P133
  • [6] JHKL photometry and the K-band luminosity function at the galactic center
    Blum, RD
    Sellgren, K
    Depoy, DL
    [J]. ASTROPHYSICAL JOURNAL, 1996, 470 (02) : 864 - 881
  • [7] SPECTROPHOTOMETRIC EVOLUTION OF ELLIPTIC GALAXIES .1. ULTRAVIOLET EXCESS AND COLOR-MAGNITUDE-REDSHIFT RELATIONS
    BRESSAN, A
    CHIOSI, C
    FAGOTTO, F
    [J]. ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1994, 94 (01) : 63 - 115
  • [8] BROWN T, 1998, APJ, V508, P139
  • [9] Discovery of an unbound hypervelocity star in the Milky Way halo
    Brown, WR
    Geller, MJ
    Kenyon, SJ
    Kurtz, MJ
    [J]. ASTROPHYSICAL JOURNAL, 2005, 622 (01) : L33 - L36
  • [10] BROWN WR, 2006, UNPUB APJ