arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1710.09403astro-ph.GAastro-ph.CO
收藏

M51 II中空间分辨的恒星形成历史:X射线星族演化

On the Spatially Resolved Star-Formation History in M51 II: X-ray Binary Population Evolution

B. D. Lehmer, R. T Eufrasio, L. Markwardt, A. Zezas, A. Basu-Zych, T. Fragos, A. E. Hornschemeier, A. Ptak, P. Tzanavaris, M. Yukita

摘要:

提出了一种新的技术,经验校准的X射线光度函数(XLF)的X射线二进制(XRB)人口演变的恒星形成事件。我们首先利用附近正面螺旋星系M51的远紫外到远红外测光的详细恒星星族合成模型来构建亚银河(~400 pc)尺度上的恒星形成历史(SFHS)图。接下来,我们使用~850 ks的累积钱德拉曝光的M51,以确定和隔离2-7 keV检测到的点源的星系内,我们使用我们的SFH地图,以恢复每个X射线源所在的恒星星族的本地属性。然后,我们根据SFH特性将星系划分为不同的子区域(例如,每恒星质量[M*]的恒星形成率[SFR]和质量加权恒星年龄),并根据发现区域的特征对X射线点源进行分组。最后,我们构造并拟合了一个参数化的XLF模型,该模型量化了XLF形状和归一化如何作为XRB星族年龄的函数演化。我们的最佳拟合模型表明,每单位恒星质量的XRB XLF在归一化中下降,约3-3.5 dex,斜率从约1000万年到约10 Gyr变陡。我们发现,我们的技术恢复的结果,从过去的研究如何XRB XLF和XRB光度标度关系随年龄的变化,并提供了一个自洽的图片XRB XLF如何随年龄的变化。

英文摘要:

We present a new technique for empirically calibrating how the X-ray luminosity function (XLF) of X-ray binary (XRB) populations evolves following a star-formation event. We first utilize detailed stellar population synthesis modeling of far-UV to far-IR photometry of the nearby face-on spiral galaxy M51 to construct maps of the star-formation histories (SFHs) on subgalactic (~400 pc) scales. Next, we use the ~850 ks cumulative Chandra exposure of M51 to identify and isolate 2-7 keV detected point sources within the galaxy, and we use our SFH maps to recover the local properties of the stellar populations in which each X-ray source is located. We then divide the galaxy into various subregions based on their SFH properties (e.g., star-formation rate [SFR] per stellar mass [M*] and mass-weighted stellar age) and group the X-ray point sources according to the characteristics of the regions in which they are found. Finally, we construct and fit a parameterized XLF model that quantifies how the XLF shape and normalization evolves as a function of the XRB population age. Our best-fit model indicates the XRB XLF per unit stellar mass declines in normalization, by ~3-3.5 dex, and steepens in slope from ~10 Myr to ~10 Gyr. We find that our technique recovers results from past studies of how XRB XLFs and XRB luminosity scaling relations vary with age and provides a self-consistent picture for how the XRB XLF evolves with age.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑