X-Ray Properties of the Point Source Population in the Spiral Galaxy NGC 5055 (M63) with Chandra
X-Ray Properties of the Point Source Population in the Spiral Galaxy NGC 5055 (M63) with Chandra
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DOI：
10.1088/1009-9271/7/3/02
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发表时间：
2007-01
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影响因子：
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通讯作者：
B. Luo;Jiyao Chen;Zhongli Zhang;Yu Wang;Jingying Wang;H. X. D. O. Physics;Fudan University;D. Physics;S. University
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文献类型：
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作者：
B. Luo;Jiyao Chen;Zhongli Zhang;Yu Wang;Jingying Wang;H. X. D. O. Physics;Fudan University;D. Physics;S. University
利用Chandra ACIS S3数据，我们研究了邻近螺旋星系NGC 5055中低质量和高质量X射线双星的X射线特性。在两个有效半径范围内共探测到43个X射线点源，其中31个位于盘上，其余12个位于凸起处。在0.3-10 keV的能量范围内，分辨点源占星系X射线辐射的主要部分，约占总计数的80%。通过光谱拟合，我们计算了所有探测到的X射线点源的0.3-10.0 keV亮度，发现它们的范围很宽，从1037 erg s−1的几倍到超过1039 erg s−1。在补偿了低光度端的不完整性后，我们发现凸起星群的校正XLF与破碎的幂律很好地拟合，在1.57+0.21 - 0.20×1038 erg s-1处发生断裂，而星盘星群的XLF轮廓符合斜率为0.93+0.07 - 0.06的单一幂律分布。在2×1038 erg s−1时，星盘的星群比核球的星群要丰富得多，这表明星盘可能经历了相对较近的、强烈的星暴，这显著增加了HMXB的星群，尽管在核区域也观察到了正在进行的星暴。类似的XLF配置文件的隆起和磁盘人口中发现M81。然而，在大多数其他旋涡星系中，从球到盘的XLF轮廓的空间变化的不同模式已被观察到，这表明星星的形成和演化历史可能比我们预期的更复杂。
Using Chandra ACIS S3 data we studied the X-ray properties of low-and high-mass X-ray binary populations in the nearby spiral galaxy NGC 5055. A total of 43 X-ray point sources were detected within two effective radii, with 31 sources located on the disk and the rest 12 sources in the bulge. The resolved point sources dominate the X-ray emission of the galaxy, accounting for about 80% of the total counts in 0.3–10 keV. From spectral fittings we calculated the 0.3–10.0 keV luminosities of all the detected X-ray point sources and found that they span a wide range from a few times 1037 erg s−1 to over 1039 erg s−1. After compensating for incompleteness at the low luminosity end, we found that the corrected XLF of the bulge population is well fitted with a broken power-law with a break at 1.57+0.21−0.20×1038 erg s−1, while the profile of the disk population's XLF agrees with a single power-law distribution of slope 0.93+0.07−0.06. The disk population is significantly richer at 2×1038 erg s−1 than the bulge population, indicating that the disk may have undergone relatively recent, strong starbursts that significantly increased the HMXB population, although ongoing starbursts are also observed in the nuclear region. Similar XLF profiles of the bulge and disk populations were found in M81. However, in most other spiral galaxies different patterns of spatial variation of the XLF profiles from the bulge to the disk have been observed, indicating that the star formation and evolution history may be more complex than we have expected.