Estimating ages and metallicities of M31 star clusters from LAMOST DR6
Estimating ages and metallicities of M31 star clusters from LAMOST DR6
复制标题
根据 LAMOST DR6 估算 M31 星团的年龄和金属丰度
DOI：
10.1051/0004-6361/202039531
复制
发表时间：
2020-11
影响因子：
6.5
通讯作者：
Ma Jun
中科院分区：
文献类型：
--
作者：
Wang Shoucheng;Chen Bingqiu;Ma Jun
上下文。确定M31团簇的金属度和年龄是研究M31本身形成和演化的基础。大天空面积多目标光纤光谱望远镜(LAMOST)在M31上开展了系统的星团和候选光谱活动。
目标。我们建立了LAMOST观测到的346个M31星系团的星表。通过结合LAMOST光谱和多波段光度测量的信息，我们发展了一种新的算法来估计这些星系团的金属丰度和年龄。
方法：研究方法。基于从文献中选取的经验训练数据集，我们使用随机森林分类器来区分年轻的和旧的聚类。年轻星系团的年龄是由其多波段光度测量的光谱能量分布拟合得到的。通过将从LAMOST光谱提取的观测光谱主成分与年轻的富金属单星群体(SSP)模型的光谱主成分进行拟合，估计了它们的金属性。对于旧的聚类，我们基于从SSP模型构建的训练数据集，在光谱主成分和/或多波段颜色与聚类参数之间建立非参数随机森林模型。然后，通过将从LAMOST光谱中提取的观测光谱主成分和从光度测量中提取的多波段颜色与所得到的随机森林模型进行拟合，来估计旧星系团的年龄和金属含量。
结果。我们得到了星表中53个年轻星系团和293个老星系团的参数。我们得到的参数与文献中的一致。首次给出了∼-30编目星系团的年龄和∼-40源的金属丰度。
Context. Determining the metallicities and ages of M31 clusters is fundamental to the study of the formation and evolution of M31 itself. The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) has carried out a systematic spectroscopic campaign of clusters and candidates in M31.
Aims. We constructed a catalogue of 346 M31 clusters observed by LAMOST. By combining the information of the LAMOST spectra and the multi-band photometry, we developed a new algorithm to estimate the metallicities and ages of these clusters.
Methods. We distinguish young clusters from old using random forest classifiers based on a empirical training data set selected from the literature. Ages of young clusters are derived from the spectral energy distribution fits of their multi-band photometric measurements. Their metallicities are estimated by fitting their observed spectral principal components extracted from the LAMOST spectra with those from the young metal-rich single stellar population (SSP) models. For old clusters we built non-parameter random forest models between the spectral principal components and/or multi-band colours and the parameters of the clusters based on a training data set constructed from the SSP models. The ages and metallicities of the old clusters are then estimated by fitting their observed spectral principal components extracted from the LAMOST spectra and multi-band colours from the photometric measurements with the resultant random forest models.
Results. We derived parameters of 53 young and 293 old clusters in our catalogue. Our resultant parameters are in good agreement with those from the literature. The ages of ∼30 catalogued clusters and metallicities of ∼40 sources are derived for the first time.
登录
查看更多内容
影响因子：
6.5
作者：
T. Puzia;K. Perrett;T. Bridges
通讯作者：
T. Puzia;K. Perrett;T. Bridges
影响因子：
6.5
作者：
Song-Yun Wang;Jun Ma;Jifeng Liu
通讯作者：
Song-Yun Wang;Jun Ma;Jifeng Liu
影响因子：
6.5
作者：
S. Perina;L. Federici;M. Bellazzini;C. Cacciari;F. F. Pecci-F.;S. G. D. D. Astronomia-S.-G.-D.-D.-Astronomia-102369218;U. Bologna;Italy.;I. A. D. Bologna
通讯作者：
S. Perina;L. Federici;M. Bellazzini;C. Cacciari;F. F. Pecci-F.;S. G. D. D. Astronomia-S.-G.-D.-D.-Astronomia-102369218;U. Bologna;Italy.;I. A. D. Bologna
影响因子：
6.5
作者：
D. L. Borgne;B. Rocca-Volmerange;P. Prugniel;A. Lançon;M. Fioc;Caroline Soubiran Institut d'Astrophysique de Paris;U. Toronto;crAl;O. Strasbourg;O. Bordeaux
通讯作者：
D. L. Borgne;B. Rocca-Volmerange;P. Prugniel;A. Lançon;M. Fioc;Caroline Soubiran Institut d'Astrophysique de Paris;U. Toronto;crAl;O. Strasbourg;O. Bordeaux
DOI：
10.1088/0004-637x/752/2/95
发表时间：
2012-04
期刊：
The Astrophysical Journal
影响因子：
--
作者：
L. Johnson;A. Seth;J. Dalcanton;N. Caldwell;M. Fouesneau;D. Gouliermis;P. Hodge;S. Larsen;K. Olsen;I. San Roman;A. Sarajedini;D. Weisz;B. Williams;L. Beerman;L. Bianchi;A. Dolphin;L. Girardi;P. Guhathakurta;J. Kalirai;D. Lang;A. Monachesi;S. Nanda;H. Rix;E. Skillman
通讯作者：
L. Johnson;A. Seth;J. Dalcanton;N. Caldwell;M. Fouesneau;D. Gouliermis;P. Hodge;S. Larsen;K. Olsen;I. San Roman;A. Sarajedini;D. Weisz;B. Williams;L. Beerman;L. Bianchi;A. Dolphin;L. Girardi;P. Guhathakurta;J. Kalirai;D. Lang;A. Monachesi;S. Nanda;H. Rix;E. Skillman