We investigate the effects of binaries on the cluster age determination for 561 open clusters in the Galactic disk via the Bayesian statistical framework.Stellar properties of these star clusters,including age,metalli...We investigate the effects of binaries on the cluster age determination for 561 open clusters in the Galactic disk via the Bayesian statistical framework.Stellar properties of these star clusters,including age,metallicity,distance modulus,color excess,binary fraction,and rotating star fraction,are derived from color–magnitude-diagrams(CMDs)via isochrone fitting to high-precision Gaia EDR3 data.Across the simple stellar population of binary and single-star,age differences can be found with the same star cluster.A Bayesian applied regression modeling software,Stan,is employed to explore how much binaries affect the age determination of open clusters.Our results present less statistically significant difference between the binary-star simple populations(bs SSPs)and the singlestar simple populations(ss SSPs)for cluster age determination.For all clusters in our sample,the ages estimated using the bs SSPs models are younger than those estimated using the ss SSPs,with a mean value of~70 Myr.However,it is found that for 52.5%clusters in our sample,ages are relatively sensitive to the presence of binaries,at least~25%younger.This suggests that in studies of open cluster age determinations,the effects of binary interactions on the whole sample are not prominent,but its effects on some clusters should still be included as an essential ingredient.展开更多
基金the National Natural Science Foundation of China(No.11863002)Yunnan Academician Workstation of Wang Jingxiu(No.202005AF150025)+1 种基金Sino-German Cooperation Project(No.GZ 1284)Research Fund Project of Yunnan Education Department(Nos.2020J0545 and 2021J0335)。
文摘We investigate the effects of binaries on the cluster age determination for 561 open clusters in the Galactic disk via the Bayesian statistical framework.Stellar properties of these star clusters,including age,metallicity,distance modulus,color excess,binary fraction,and rotating star fraction,are derived from color–magnitude-diagrams(CMDs)via isochrone fitting to high-precision Gaia EDR3 data.Across the simple stellar population of binary and single-star,age differences can be found with the same star cluster.A Bayesian applied regression modeling software,Stan,is employed to explore how much binaries affect the age determination of open clusters.Our results present less statistically significant difference between the binary-star simple populations(bs SSPs)and the singlestar simple populations(ss SSPs)for cluster age determination.For all clusters in our sample,the ages estimated using the bs SSPs models are younger than those estimated using the ss SSPs,with a mean value of~70 Myr.However,it is found that for 52.5%clusters in our sample,ages are relatively sensitive to the presence of binaries,at least~25%younger.This suggests that in studies of open cluster age determinations,the effects of binary interactions on the whole sample are not prominent,but its effects on some clusters should still be included as an essential ingredient.
