Catalog Service: 346 M31 star clusters and their parameters
Description
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. 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. 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. 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.
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Publisher: CDSivo://CDS[Pub. ID]
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This resource was registered on: 2021 Jan 22 09:46:17ZThis resource description was last updated on: 2021 Oct 21 00:00:00Z
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This is service that does not comply with any IVOA standard but instead provides access to special capabilities specific to this resource.
This is a standard IVOA service that takes as input an ADQL or PQL query and returns tabular data.
This is a standard IVOA service that takes as input a position in the sky and a radius and returns catalog records with positions within that radius.
Cone search capability for table J/A+A/645/A115/table1 (Cluster names, positions and parameters)
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