ASteCA - Automated Stellar Cluster Analysis

Abstract

We present ASteCA (Automated Stellar Cluster Analysis), a suit of tools designed to fully automatize the standard tests applied on stellar clusters to determine their basic parameters. The set of functions included in the code make use of positional and photometric data to obtain precise and objective values for a given cluster's center coordinates, radius, luminosity function and integrated color magnitude, as well as characterizing through a statistical estimator its probability of being a true physical cluster rather than a random overdensity of field stars. ASteCA incorporates a Bayesian field star decontamination algorithm capable of assigning membership probabilities using photometric data alone. An isochrone fitting process based on the generation of synthetic clusters from theoretical isochrones and selection of the best fit through a genetic algorithm is also present, which allows ASteCA to provide accurate estimates for a cluster's metallicity, age, extinction and distance values along with its uncertainties. To validate the code we applied it on a large set of over 400 synthetic MASSCLEAN clusters with varying degrees of field star contamination as well as a smaller set of 20 observed Milky Way open clusters (Berkeley 7, Bochum 11, Czernik 26, Czernik 30, Haffner 11, Haffner 19, NGC 133, NGC 2236, NGC 2264, NGC 2324, NGC 2421, NGC 2627, NGC 6231, NGC 6383, NGC 6705, Ruprecht 1, Tombaugh 1, Trumpler 1, Trumpler 5 and Trumpler 14) studied in the literature. The results show that ASteCA is able to recover cluster parameters with an acceptable precision even for those clusters affected by substantial field star contamination. ASteCA is written in Python and is made available as an open source code which can be downloaded ready to be used from it's official site.

Site: http://asteca.github.io/

References in corpus (20)

• The ACS Nearby Galaxy Survey Treasury IX. Constraining asymptotic giant branch evolution with old metal-poor galaxies
• Introduction to astroML: Machine Learning for Astrophysics
• A systematic survey for infrared star clusters with |b|<20deg using 2MASS
• The Distances to Open Clusters from Main-Sequence Fitting. III. Improved Accuracy with Empirically Calibrated Isochrones
• Open clusters in dense fields: the importance of field-star decontamination for NGC5715, Lynga4, Lynga9, Trumpler23, Trumpler26 and Czernik37
• CCD BV survey of 42 open clusters
• Inverting Color-Magnitude Diagrams to Access Precise Star Cluster Parameters: A Bayesian Approach
• Discovery of two distinct red clumps in NGC419: a rare snapshot of a cluster at the onset of degeneracy
• Open Clusters as Galactic Disk Tracers: I. Project Motivation, Cluster Membership and Bulk Three-Dimensional Kinematics
• The Gaia-ESO Survey: Stellar content and elemental abundances in the massive cluster NGC 6705
• Physical parameters of 15 intermediate-age LMC clusters from modelling of HST colour-magnitude diagrams
• Properties of Star Clusters - II: Scale Height Evolution of Clusters
• On the metallicity of open clusters I. Photometry
• A robust statistical estimation of the basic parameters of single stellar populations. I. Method
• Characterization of open cluster remnants
• Kinematic parameters and membership probabilities of open clusters in the Bordeaux PM2000 catalogue
• Investigating the age and structure of the infrared old open clusters LK1, LK10, FSR1521 and FSR1555
• The embedded cluster DBSB48 in the nebula Hoffleit18: comparison with Trumpler14
• Investigating star formation in the young open cluster NGC 6383
• NGC 4337: an over-looked old cluster in the inner disc of the Milky Way

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• A Multi-Wavelength Study of the Segue 3 Cluster
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