论文标题
天体物理和结构参数，以及开放群集NGC 1245和NGC 2099的动态演变
Astrophysical and Structural Parameters, And Dynamical Evolution Of The Open Clusters NGC 1245 And NGC 2099
论文作者
论文摘要
我们从2MASS JHK和GAIA DR2光度计 /天文数据库中得出了开放簇NGC 1245和NGC 2099的天体和结构参数。他们的可能成员已从Gaia DR2正确的运动数据中确定。我们的e（b-v）值（2个质量）略小于文献值，而我们的e（b-v）值（Gaia dr2）与不确定性中的文献一致。他们的距离模量/距离和年龄与文献相吻合。 NGC 1245具有陡峭的负核质量函数斜率（MFS）（χ_core= -1.24）。它的光环（χ_halo=+0.78）和整体（χ_overall= -0.95）MFS意味着它由于其[τ_rlx（整体），τ_overall]，τ_overall] = [302 myr，5]，其质量从其核心出现了小规模质量分离的迹象。 NGC 2099的MFS在核心中是非常负陡峭（χ_core= -2.67），而光环中的陡峭陡峭（χ_halo=+1.41）。这种MF从核心到郊区浸泡的MF斜率表明，核心中的低质量恒星被转移到集群的郊区，而由于质量分离，大量的恒星沉入了核心。 NGC 2099的平坦总体MF（χ_overall=+0.91），其τ_overall= 8呈现质量分离的迹象。这些具有相对较大的8700 MSolar（NGC 1245）和5660 MSolar（NGC 2099）的OC，位于RGC> 9 kpc的位置，暴露于外部扰动，例如潮汐效应和冲击波，并且它们在低预压中失去了恒星。
We derive astrophysical and structural parameters of open clusters NGC 1245 and NGC 2099 from 2MASS JHKs and Gaia DR2 photometric / astrometric data bases. Their likely members have been determined from Gaia DR2 proper motion data. Our E(B-V) values (2MASS) are slightly smaller than the literature values, whereas our E(B-V) values (Gaia DR2) agree with the literature within the uncertainties. Their distance moduli/distances and ages are in good coincident with the literature. NGC 1245 has steep negative core mass function slope (MFs) (χ_core=-1.24). Its halo (χ_halo=+0.78) and overall (χ_overall=-0.95) MFs mean that it presents signs of small-scale mass segregation to the outer regions from its core, due to its [τ_rlx (overall),τ_overall ]=[302 Myr,5]. The MFs of NGC 2099 is very negative steep (χ_core=-2.67) in the core, and quite positive steep (χ_halo=+1.41) in the halo. This kind of MF slope steeping from the core to the outskirts indicates that low-mass stars in the core are transferred to the cluster's outskirts, while massive stars sink in the core, because of mass segregation. NGC 2099's flat overall MFs (χ_overall=+0.91) and its τ_overall=8 presents a sign of mass segregation. These OCs with the relatively large masses 8700 Msolar (NGC 1245) and 5660 Msolar (NGC 2099), which locate at RGC > 9 kpc, expose to external perturbations such as tidal effects and shock waves, and they lose their stars in low-proportions.
