J/A+A/658/A51           New M31 star cluster candidates            (Wang+, 2022)

Identification of new M31 star cluster candidates from PAndAS images using convolutional neural networks. Wang S., Chen B., Ma J., Long Q., Yuan H., Liu D., Zhou Z., Liu W., Chen J., He Z. <Astron. Astrophys. 658, A51 (2022)> =2022A&A...658A..51W 2022A&A...658A..51W (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Associations, stellar ; Photometry ; Optical Keywords: galaxies: star clusters: general - galaxies: star clusters: individual: M31 Abstract: Identification of new star cluster candidates in M 31 is fundamental for the study of the M 31 stellar cluster system. The machine-learning method convolutional neural network (CNN) is an efficient algorithm for searching for new M 31 star cluster candidates from tens of millions of images from wide-field photometric surveys. We search for new M 31 cluster candidates from the high-quality g- and i-band images of 21 245 632 sources obtained from the Pan-Andromeda Archaeological Survey (PAndAS) through a CNN. We collected confirmed M 31 clusters and noncluster objects from the literature as our training sample. Accurate double-channel CNNs were constructed and trained using the training samples. We applied the CNN classification models to the PAndAS g- and i-band images of over 21 million sources to search new M 31 cluster candidates. The CNN predictions were finally checked by five experienced human inspectors to obtain high-confidence M 31 star cluster candidates. After the inspection, we identified a catalogue of 117 new M 31 cluster candidates. Most of the new candidates are young clusters that are located in the M 31 disk. Their morphology, colours, and magnitudes are similar to those of the confirmed young disk clusters. We also identified eight globular cluster candidates that are located in the M 31 halo and exhibit features similar to those of confirmed halo globular clusters. The projected distances to the M 31 centre for three of them are larger than 100kpc. Description: File table2.dat contains 117 M31 star cluster candidates and their coordinates, magnitudes, projected radii, ellipticities, position angles, summed scores. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2.dat 72 117 Cluster names, positions and parameters -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 12 A12 --- Name Name of the star cluster candidate, CandidateNNN 14 I1 h RAh Right Ascension (J2000) 16- 17 I2 min RAm Right Ascension (J2000) 19- 24 F6.3 s RAs Right Ascension (J2000) 26 A1 --- DE- Declination sign (J2000) 27- 28 I2 deg DEd Declination (J2000) 30- 31 I2 arcmin DEm Declination (J2000) 33- 37 F5.2 arcsec DEs Declination (J2000) 39- 44 F6.3 mag gmag g-band magnitude 46- 51 F6.3 mag imag i-band magnitude 53- 57 F5.1 kpc Rproj Projected radii from the M31 centre 59- 62 F4.2 --- ell Ellipticity 64- 69 F6.2 deg PA [] Position angle 71- 72 I2 --- Score Summed scores by visual inspectors -------------------------------------------------------------------------------- Acknowledgements: Shoucheng Wang, scwang(at)nao.cas.cn
(End) Patricia Vannier [CDS] 16-Nov-2021
The document above follows the rules of the Standard Description for Astronomical Catalogues; from this documentation it is possible to generate f77 program to load files into arrays or line by line