X-RAY OBSERVATIONS OF NGC-1851 AND THE GLOBULAR-CLUSTER LMXBS

被引:14
作者
CALLANAN, PJ
PENNY, AJ
CHARLES, PA
机构
[1] RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND
[2] UNIV OXFORD,DEPT ASTROPHYS,OXFORD OX1 3RH,ENGLAND
关键词
STARS; NEUTRON; GLOBULAR CLUSTERS; INDIVIDUAL; NGC; 1851; X-RAYS;
D O I
10.1093/mnras/273.1.201
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present new Ginga observations of the globular cluster X-ray source 4U0513-40 in NGC 1851. Despite the 2-d time-base of the observations, no eclipsing or dipping modulation was found. The spectrum can be well modelled by a power law of index 2.1 to energies of at least 10 keV. We find from archive EXOSAT data that an additional blackbody contribution is required at lower energies. We reanalyse the EXOSAT spectra of the other cluster sources, and find that in the majority of cases the addition of a blackbody significantly improves the fit: blackbody radii of similar to a few km are found. We discuss the implications of these findings for our models of the cluster sources.
引用
收藏
页码:201 / 205
页数:5
相关论文
共 25 条
  • [1] AURIERE M, 1992, ASTRON ASTROPHYS, V263, P82
  • [2] AURIERE M, 1984, ASTRON ASTROPHYS, V138, P415
  • [3] COLOR MAPS OF X-RAY GLOBULAR-CLUSTERS
    BAILYN, CD
    GRINDLAY, JE
    COHN, H
    LUGGER, PM
    [J]. ASTROPHYSICAL JOURNAL, 1988, 331 (01) : 303 - &
  • [4] EXOSAT OBSERVATIONS OF THE X-RAY SOURCE IN M15
    CALLANAN, PJ
    FABIAN, AC
    TENNANT, AF
    REDFERN, RM
    SHAFER, RA
    [J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1987, 224 (03) : 781 - 789
  • [5] DJORGOVSKI S, 1993, ASTR SOC P, V50, P373
  • [6] ERCAN EN, 1985, ESA SP239, P121
  • [7] ERCAN N, 1994, UNPUB REV MOD PHYS D
  • [8] FABIAN AC, 1975, MNRAS, V172
  • [9] EMPIRICAL RELATION BETWEEN INTERSTELLAR X-RAY ABSORPTION AND OPTICAL EXTINCTION
    GORENSTEIN, P
    [J]. ASTROPHYSICAL JOURNAL, 1975, 198 (01) : 95 - 101
  • [10] HAYASHIDA K, 1989, PUBL ASTRON SOC JPN, V41, P373