Automated search for galactic star clusters in large multiband surveys: I. Discovery of 15 new open clusters in the Galactic anticenter region

摘要

Aims: According to some estimations, there are as many as 100000 openclusters in the Galaxy, but less than 2000 of them have been discovered,measured, and cataloged. We plan to undertake data mining of multiwavelengthsurveys to find new star clusters. Methods: We have developed a new method tosearch automatically for star clusters in very large stellar catalogs, which isbased on convolution with density functions. We have applied this method to asubset of the Two Micron All Sky Survey catalog toward the Galactic anticenter.We also developed a method to verify whether detected stellar groups are realstar clusters, which tests whether the stars that form the spatial density peakalso fall onto a single isochrone in the color-magnitude diagram. By fitting anisochrone to the data, we estimate at the same time the main physicalparameters of a cluster: age, distance, color excess. Results: For the presentpaper, we carried out a detailed analysis of 88 overdensity peaks detected in afield of $16\times16$ degrees near the Galactic anticenter. From this analysis,15 overdensities were confirmed to be new open clusters and the physical andstructural parameters were determined for 12 of them; 10 of them werepreviously suspected to be open clusters by Kronberger (2006) and Froebrich(2007). The properties were also determined for 13 yet-unstudied known openclusters, thus almost tripling the sample of open clusters with studiedparameters in the anticenter. The parameters determined with this method showeda good agreement with published data for a set of well-known clusters.