论文标题
年轻开放簇IC 1442，KING 21和Trumpler 7的光度研究
Photometric study of the young open clusters IC 1442, King 21, and Trumpler 7
论文作者
论文摘要
我们对三个研究不足的年轻开放簇IC 1442，KING 21和Trumpler 7（TR 7）进行了UBVRCIC光度法研究。我们分别在IC 1442，King 21和TR 7中使用Gaia DR2的适当运动和视差获得了263、244和128个成员恒星。对于这些簇，红粉红色E（B-V）得出为0.54 +/- 0.04、0.76 +/- 0.06和0.38 +/- 0.04 mag。与太阳金属等速线相比的观察到的颜色 - 磁性图（CMD）的比较可产生原木（年龄）= 7.40 +/- 0.30，7.70 +/- 0.20，以及7.85 +/- 0.25 +/- 0.25 yr和相应的距离2847 +/- 2847 +/- 238，238，2622 +/- 156+/156，和IC 144 PCOR IC 144 PCOR IC 144 PCON，IC。发现IC 1442，King 21和TR 7的估计质量函数（MF）斜率分别为-1.94 +/- 0.18，-1.54 +/- 0.32和-2.31 +/- 0.29。在这些簇的内部和外部区域中分别确定的MF斜率的研究在外部区域中提供了更陡峭的斜率，这表明簇中斜率和质量分离的空间变化。我们在这些簇中的动态研究后发现了质量分离的证据。对于簇IC 1442，KING 21和TR 7分别为74、26和34 MYR。 IC 1442中的质量分离可能是由早期动态弛豫引起的。估计的放松时间远低于King 21和TR 7的年龄，这表明这些簇是动态放松的。
We carried out UBVRcIc photometric study of three poorly studied young open clusters IC 1442, King 21, and Trumpler 7 (Tr 7). We obtained 263, 244, and 128 member stars using Gaia DR2 proper motions and parallaxes in IC 1442, King 21, and Tr 7, respectively. The reddening, E(B-V), was derived to be 0.54+/-0.04, 0.76+/-0.06, and 0.38+/-0.04 mag for these clusters. The comparison of observed colour-magnitude diagrams (CMDs) with solar metallicity isochrones yields log(Age) = 7.40+/-0.30, 7.70+/-0.20, and 7.85+/-0.25 yr and corresponding distances 2847+/-238, 2622+/-156, and 1561+/-74 pc for IC 1442, King 21, and Tr 7, respectively. The estimated mass function (MF) slopes are found to be -1.94+/-0.18, -1.54+/-0.32, and -2.31+/-0.29 for IC 1442, King 21, and Tr 7, respectively. The study of MF slopes determined separately in the inner and the outer regions of these clusters gives a steeper slope in outer region which suggests spatial variation in slope and mass segregation in the clusters. We found evidence of mass segregation after dynamical study in these clusters. The obtained relaxation time is 74, 26, and 34 Myr for the clusters IC 1442, King 21, and Tr 7, respectively. The mass segregation in IC 1442 may be caused by early dynamical relaxation. The estimated relaxation time is well below to the ages of King 21 and Tr 7 which indicates that these clusters are dynamically relaxed.
