Faint Surface Photometry of the Halo of M31
Faint Surface Photometry of the Halo of M31
复制标题
M31 光晕的微弱表面光度测量
DOI：
10.1007/978-94-009-1687-6_5
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
S. Bergh
中科院分区：
文献类型：
--
作者：
C. Pritchet;S. Bergh
我们获得了M31红巨星分支尖端附近恒星的计数，并利用这些计数估算了M31晕的表面亮度，亮度低至μ v <$30 mag arcsec−2（R <$20 kpc）。沿着M31晕短轴的表面亮度很好地用一个单一的德·沃库勒定律（0.2 <$R[kpc]<$20）来表示。另外，M31的外晕也可以用幂律密度分布[itp（R）<$R−5]来模拟。这一结果表明，M31晕中的球状星团成分（其p <$R −3）比该星系的恒星晕更广。在μ v = 28 mag arcsec−2（R = 10 kpc）时，M31晕的轴比为c/a = 0.55 ± 0.05。
We have obtained counts of stars near the tip of the red giant branch of M31, and have used these counts to estimate the surface brightness of the halo of M31 down to a level of μ v ≃ 30 mag arcsec−2 (R ≈ 20 kpc). The surface brightness along the minor axis of the M31 halo is well-represented by a single de Vaucouleurs law (0.2 ≲ R[kpc] ≲ 20). Alternatively, the outer halo of M31 can also be modelled by a power-law density distribution of the form [itp(R) ∝ R−5. This result suggests that the globular cluster component of the halo of M31 (for which p ∝ R −3) is more extended than the stellar halo of this galaxy. At μ v ≈ 28 mag arcsec−2 (R ≈ 10 kpc), the axial ratio of the halo of M31 is found to be c/a = 0.55 ± 0.05.