疏散星团 Collinder 110 和 NGC 2477 的动力学演化
Dynamical Evolution of The Open Clusters Collinder 110 and NGC 2477
- İstanbul University（伊斯坦布尔大学）
- Yeditepe University（耶迪特佩大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
利用 Gaia DR3 数据识别 Collinder 110 和 NGC 2477 的成员，推导其参数，发现两者动力学演化先进，受潮汐影响，但位于巨分子云稀少区域而得以存活至今。
AI中文摘要：
利用 Gaia DR3 测光和天体测量数据，我们识别了疏散星团 Collinder 110 和 NGC 2477 的可能成员，并推导了它们的天体物理和动力学参数。我们得到 Collinder 110 和 NGC 2477 的色余值分别为 $E(B-V) = 0.43 \pm 0.05$ 和 $0.33 \pm 0.04$，年龄分别为 $1.82 \pm 0.10$ Gyr 和 $1.05 \pm 0.10$ Gyr。在不确定度范围内，由颜色-星等图得到的距离（$2.09 \pm 0.06$ 和 $1.38 \pm 0.04$ kpc）与 Gaia DR3 视差得到的距离（$2.08 \pm 0.31$ 和 $1.45 \pm 0.11$ kpc）一致。两个星团都表现出较大的核半径和极限半径。Collinder 110 的核半径（$R_c$）不遵循随演化参数（$\log\tau_2$）增加而预期的下降趋势。除了失去部分低质量恒星外，其相对较大的 $R_c$ 可能反映了原始条件或可能存在恒星质量黑洞。相对较大的 $R_c/R_h$ 比值，加上它们先进的动力学演化（$\log\tau_2 = 1.24$ 和 $1.34$），表明在其中心区域发生了显著的两体弛豫和质量分层。较小的 $R_h/R_j$ 值（$0.32$ 和 $0.16$）表明，在内部和外部过程的共同影响下，低质量恒星在相对较大的 Jacobi 半径内发生了动力学重新分布。然而，它们较大的 $R_t/R_j$ 比值（$1.60$ 和 $1.23$）意味着两个星团都受到潮汐影响，并可能已将其部分低质量恒星族群丢失到银河系场中。尽管存在这些影响，它们位于第三银河象限的位置（那里巨分子云相对稀少）可能解释了它们分别存活至今的年龄 $1.82$ 和 $1.05$ Gyr。
英文摘要：
Using Gaia DR3 photometric and astrometric data, we identified the likely members of the open clusters Collinder 110 and NGC 2477, and derived their astrophysical and dynamical parameters. We obtained reddening values of $E(B-V) = 0.43 \pm 0.05$ and $0.33 \pm 0.04$, and ages of $1.82 \pm 0.10$ Gyr and $1.05 \pm 0.10$ Gyr for Collinder 110 and NGC 2477, respectively. Within the uncertainties, the distances derived from the color-magnitude diagrams ($2.09 \pm 0.06$ and $1.38 \pm 0.04$ kpc) are consistent with those obtained from Gaia DR3 parallaxes ($2.08 \pm 0.31$ and $1.45 \pm 0.11$ kpc). Both clusters exhibit large core and limiting radii. The core radius ($R_c$) of Collinder 110 does not follow the expected decreasing trend with increasing evolutionary parameter ($\logτ_2$). In addition to losing part of its low-mass stellar content, its relatively large $R_c$ may reflect primordial conditions and/or the presence of a possible stellar-mass black hole. The relatively large $R_c/R_h$ ratios, together with their advanced dynamical evolution ($\logτ_2 = 1.24$ and $1.34$), indicate that significant two-body relaxation and mass segregation have occurred within their central regions. The small values of $R_h/R_j$ ($0.32$ and $0.16$) suggest that low-mass stars have dynamically redistributed within the comparatively large Jacobi radii under the combined influence of internal and external processes. However, their large $R_t/R_j$ ratios ($1.60$ and $1.23$) imply that both clusters are tidally affected and have likely lost part of their low-mass stellar populations to the Galactic field. Despite these effects, their locations in the third Galactic quadrant, where giant molecular clouds are relatively scarce, may explain their survival to their present ages of $1.82$ and $1.05$ Gyr, respectively.
