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J/A+A/507/1375     HST/ACS VI data of M31 globular clusters      (Perina+, 2009)

HST/ACS colour-magnitude diagrams of M31 globular clusters. Perina S., Federici L., Bellazzini M., Cacciari C., Fusi Pecci F., Galleti S. <Astron. Astrophys. 507, 1375 (2009)> =2009A&A...507.1375P
ADC_Keywords: Galaxies, nearby ; Clusters, globular ; Photometry, HST Keywords: galaxies: individual: M 31 - galaxies: star clusters - catalog - galaxies: Local Group Abstract: With the aim of increasing the sample of M31 clusters for which a colour-magnitude diagram is available, we searched the HST archive for ACS images containing objects included in the Revised Bologna Catalogue of M31 globular clusters (RBC Version 3.5 available at: http://www.bo.astro.it/M31). Sixty-three such objects were found. We used the ACS images to confirm or revise their classification and were able to obtain useful CMDs for 11 old globular clusters and 6 luminous young clusters. We obtained simultaneous estimates of the distance, reddening, and metallicity of old clusters by comparing their observed field-decontaminated CMDs with a grid of template clusters of the Milky Way. We estimated the age of the young clusters by fitting with theoretical isochrones. Description: Tables B008.dat,B010.dat,B023.dat,B088.dat,B158.dat,B220.dat,B224.dat, B225.dat, B255D.dat,B366.dat,B407.dat present the photometry of the individual stars of 11 M31 globular clusters. The observations were carried out with the ACS on board of the HST, employing the HRC+F606W/F814W filters for B023,B158,B225,and the WFC+ F606W/F814W/F435W for the other clusters. The data reduction has been performed using the ACS module of DOLPHOT, a point spread function-fitting package specifically devoted to the photometry of HST data, that provides as output the magnitudes and the pixel positions of the detected sources, and a number of quality parameters for a suitable sample selection. The tables present, for the chip holding the cluster, all the stars with valid measurements in both passbands, global quality flag=1, crowding parameter<0.5 and chi-square parameter<1.5 if V>22.5,and <2.5 if V<22.5. The x,y coordinates, the magnitudes both in the Vegamag and in the Johnson-Cousins systems, the global parameters 'chi', signal to noise, sharpness, and the chip number are listed for each of the selected stars. Objects: -------------------------------------------------------------------- RA (2000) DE Designation(s) (file) -------------------------------------------------------------------- 00 40 30.3 +41 16 09 Bol 008 = M31GC J004031+411610 (b008.dat) 00 40 31.6 +41 14 22 Bol 010 = M31GC J004032+411422 (b010.dat) 00 41 01.3 +41 13 45 Bol 023 = M31GC J004101+411345 (b023.dat) 00 42 21.1 +41 32 14 Bol 088 = M31GC J004221+413214 (b088.dat) 00 43 14.4 +41 07 21 Bol 158 = M31GC J004314+410721 (b158.dat) 00 44 19.5 +41 30 35 Bol 220 = M31GC J004419+413036 (b220.dat) 00 44 27.1 +41 28 49 Bol 224 = M31GC J004427+412851 (b224.dat) 00 44 29.6 +41 21 35 Bol 225 = M31GC J004430+412137 (b225.dat) 00 44 48.6 +42 06 13 Bol D255 = M31GC J004449+420613 (b255d.dat) 00 44 46.7 +42 03 50 Bol 366 = M31GC J004447+420350 (b366.dat) 00 50 10.0 +41 41 01 Bol 407 = M31GC J005010+414101 (b407.dat) -------------------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file clusters.dat 60 11 Cluster list b008.dat 100 170437 Stellar Photometry of the M31 GC B008 b010.dat 100 173486 Stellar Photometry of the M31 GC B010 b023.dat 100 8318 Stellar Photometry of the M31 GC B023 b088.dat 100 166624 Stellar Photometry of the M31 GC B088 b158.dat 100 11729 Stellar Photometry of the M31 GC B158 b220.dat 100 195290 Stellar Photometry of the M31 GC B220 b224.dat 100 195290 Stellar Photometry of the M31 GC B224 b225.dat 100 10865 Stellar Photometry of the M31 GC B225 b255d.dat 100 161913 Stellar Photometry of the M31 GC B255D b366.dat 100 156283 Stellar Photometry of the M31 GC B366 b407.dat 100 37042 Stellar Photometry of the M31 GC B407
See also: J/A+A/416/917 : M31 globular clusters revised Bologna Catalog (Galleti+ 2004) J/A+A/471/127 : New globular clusters in M31 (Galleti+, 2007) J/AJ/114/1488 : Globulars in M31 (Holland+ 1997) J/AJ/119/727 : M31 globular clusters photometry (Barmby+, 2000) J/AJ/122/2458 : M31 globular clusters from HST (Barmby+, 2001) J/AJ/133/2764 : M31 globular clusters structural parameters (Barmby+, 2007) J/AcA/48/455 : Globular Clusters in M31 and M33 (Mochejska+, 1998) J/ApJS/173/643 : GALEX UV photometry of M31 Globular Clusters (Rey+, 2007) J/MNRAS/392/L55 : M31 globular clusters from K-band photometry (Peacock+, 2009) http://www.bo.astro.it/M31 : Revised Bologna Catalogue of M31 globular clusters Byte-by-byte Description of file: clusters.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name Cluster name 10- 11 I2 h RAh Right ascension (J2000) 13- 14 I2 min RAm Right ascension (J2000) 16- 19 F4.1 s RAs Right ascension (J2000) 21 A1 --- DE- Declination sign (J2000) 22- 23 I2 deg DEd Declination (J2000) 25- 26 I2 arcmin DEm Declination (J2000) 28- 29 I2 arcsec DEs Declination (J2000) 31- 50 A20 --- SName Simbad name 52- 60 A9 --- FileName Name of the file with cluster photometry
Byte-by-byte Description of file: b*.dat
Bytes Format Units Label Explanations
3- 8 I6 --- ID Identification number 11- 17 F7.2 pix Xpos X pixel coordinates (1) 19- 25 F7.2 pix Ypos Y pixel coordinates (1) 28- 33 F6.3 mag Vmag V band magnitude 35- 40 F6.3 mag Imag I band magnitude 42- 47 F6.3 mag F606W F606W band magnitude (Vegamag system) 49- 54 F6.3 mag F814W F814W band magnitude (Vegamag system) 56- 61 F6.3 mag e_F606W 1-sigma uncertainty in F606W 63- 68 F6.3 mag e_F814W 1-sigma uncertainty in F814W 71- 75 F5.3 --- Chi Value of the DOLPHOT/ACS Chi statistics (4) 77- 82 F6.1 --- S/N Signal-to-Noise ratio 84- 89 F6.3 --- Sharp DOLPHOT/ACS sharpness parameter (2) 92- 96 F5.3 mag Crowd DOLPHOT/ACS crowding parameter (3) 100 I1 --- Chip ? ACS/WFC chip number
Note (1): Center and pixels values as follows: B008 center on ACS/WFC chip1: (x,y)=( 998,1761), 1 pixel ≃0.05" B010 center on ACS/WFC chip2: (x,y)=(2977, 400), 1 pixel ≃0.05" B023 center on the ACS/HRC : (x,y)=( 516, 528), 1 pixel ≃0.025" B088 center on ACS/WFC chip2: (x,y)=( 998,1761), 1 pixel ≃0.05" B158 center on ACS/HRC: (x,y)=( 521, 580), 1 pixel ≃0.025" B220 center on ACS/WFC chip2: (x,y)=( 728, 763), 1 pixel ≃0.05" B224 center on ACS/WFC chip2: (x,y)=(3462, 149), 1 pixel ≃0.05" B225 center on ACS/HRC: (x,y)=( 543, 520), 1 pixel ≃0.025" B255D center on ACS/WFC chip1: (x,y)=( 669,1142), 1 pixel ≃0.05" B366 center on ACS/WFC chip2: (x,y)=(2938, 717), 1 pixel ≃0.05" B407 center on ACS/WFC chip1: (x,y)=(1057, 399), 1 pixel ≃0.05"Note (2): the DOLPHOT sharpness parameter is zero for perfect stellar fit, Note (2): the DOLPHOT sharpness parameter is zero for perfect stellar fit, negative for too broad fit (perhaps a blend, cluster or galaxy), and positive for too sharp fit (perhaps a cosmic ray). Note (3): the crowding parameter tells how much brighter the star would be if nearby stars would not be fit simultaneously. The value is zero for an isolated star. Note (4): a good, clean star in an uncrowded field should have a χ value of 1.5 or less; values up to 2.5 are reasonable. In very crowded fields, good stars may have χ values up to 5.
Acknowledgements: Luciana Federici, luciana.federici(at)oabo.inaf.it
(End) Patricia Vannier [CDS] 12-Nov-2009
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

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