论文标题
探索球状簇中X射线源的质量分离效应。 iii。 M28中二进制中断的迹象
Exploring the Mass Segregation Effect of X-ray Sources in Globular Clusters. III. Signs of Binary Disruption in M28
论文作者
论文摘要
使用档案{\ it chandra}观测值,总有效暴露为323 ks,我们得出了凸起的球状群集M28中的点源的更新目录。该目录在$ \ sim475 \,\ rm arcmin^{2} $的区域内包含502个X射线源,并且在此群集中首先检测到这些来源的$ 90 \%以上。我们发现M28中X射线源的径向分布曲线的显着下降,明亮的预计距离和分布的宽度($ l_ {x} \ gtrsim 4.5 \ times 10^{30} {\ rm \ rm \ erg \ erg \ erg \ erg \ \ \ \ \ \ s^{ - 1}} 4.5 \ times 10^{30} {\ rm \ erg \ \ \ \,s^{ - 1}} $)来源。与微弱的来源($ 1.09 \ pm0.14 \,m _ {\ odot} $)相比,“广义的国王模型”的合适量的平均质量($ 1.30 \ pm0.15 \,m _ {\ odot} $),这支持了巨大的质量segregration deaste deaste the gcs in gcs in gcs之间。与47 TUC和TERZAN 5相比,我们表明M28的动态年龄与Terzan 5相当,并且比47 TUC小得多,但是它的发展速度更快(即,与47 TUC相比,它更快(即具有较小的两体弛豫时间表)。这些特征可能暗示了M28中潮汐冲击的簇动力学演变的加速效应。 Besides, we find an abnormal deficiency of X-ray sources in the central region ($R \lesssim 1.5 \rm~arcmin$) of M28 than its outskirts, which indicate that M28 may have suffered an early phase of primordial binary disruption within its central region, and mass segregation effect will erase such a phenomenon as cluster evolve to older dynamical age.
Using archival {\it Chandra} observations with a total effective exposure of 323 ks, we derive an updated catalog of point sources in the bulge globular cluster M28. The catalog contains 502 X-ray sources within an area of $\sim475\, \rm arcmin^{2}$, and more than $90\%$ of these sources are first detected in this cluster. We find significant dips in the radial distribution profiles of X-ray sources in M28, with the projected distance and width of the distribution dip for bright ($L_{X} \gtrsim 4.5\times 10^{30} {\rm\ erg\ \,s^{-1}}$) X-ray sources are larger than the faint ($L_{X} \lesssim 4.5\times 10^{30} {\rm\ erg\ \,s^{-1}}$) sources. The "generalized King model" fitting give a slightly larger average mass for the bright sources ($1.30\pm0.15\,M_{\odot}$) than the faint sources ($1.09\pm0.14\,M_{\odot}$), which support a universal mass segregation delay between heavy objects in GCs. Compared with 47 Tuc and Terzan 5, we show that the dynamical age of M28 is comparable to Terzan 5 and much smaller than 47 Tuc, but it is evolving more fast (i.e., with smaller two-body relaxation timescale) than 47 Tuc. These features may suggest an acceleration effect of cluster dynamical evolution by tidal shock in M28. Besides, we find an abnormal deficiency of X-ray sources in the central region ($R \lesssim 1.5 \rm~arcmin$) of M28 than its outskirts, which indicate that M28 may have suffered an early phase of primordial binary disruption within its central region, and mass segregation effect will erase such a phenomenon as cluster evolve to older dynamical age.