论文标题
球状簇中多个种群的蒙特卡洛模拟：二进制恒星对第二代的初始大小的约束
Monte Carlo simulations of multiple populations in globular clusters: constraints on the initial size of the second generation from binary stars
论文作者
论文摘要
我们介绍了对蒙特卡洛模拟的调查的结果，该蒙特卡洛模拟对两个人群中原始二进制物的大量恒星，包括大量（F_B = 50％）的恒星。考虑到潮汐场的影响，两体弛豫，恒星进化和三个/四体相互作用，遵循两个恒星种群的动态演化。将存活的二进制文件的比例与观察性偏差和不确定性有关，与在实际球状簇中执行的可用径向速度时间序列进行了比较，并用于限制第二代的初始空间浓度。第二代二进制文件的比例似乎仅取决于总簇质量与第二代的初始大小之间的比率，这决定了该恒星种群范围内平均速度分散剂的比率。尽管存在各种不确定性，但我们发现只能假设第二代（R_H，s〜0.1（m/10^6 m_s）PC）的初始浓度很强。由于潮汐场对第一代结构特性有直接的影响，第一代二元分数的演变对潮汐场强度（簇轨道偏心率的不可忽略的影响）更为敏感。
We present the result of a survey of Monte Carlo simulations of globular clusters hosting two generations of stars including a large (f_b=50%) fraction of primordial binaries in both populations. The dynamical evolution of the two stellar populations is followed for a Hubble time taking into account the effect of the tidal field, two-body relaxation, stellar evolution and three/four-bodies interactions. The fraction of surviving binaries, once accounted for the observational bias and uncertainties, is compared with the available radial velocity time-series performed in real globular clusters, and it is used to constrain the initial spatial concentration of the second generation. The fraction of second generation binaries appears to depend only on the ratio between the total cluster mass and the initial size of the second generation which determines the average velocity dispersion across the extent of this stellar population. In spite of the various uncertainties, we find that the observed fraction can be obtained only assuming a strong initial concentration of the second generation (r_h,S~ 0.1 (M/10^6 M_s) pc). The evolution of the first generation binary fraction is more sensitive to the tidal field strength (with a non negligible effect of the cluster orbital eccentricity) since the tidal field has a direct impact on the first generation structural properties.
