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J/A+A/467/1003    Photometry of star clusters in NGC 1380  (Chies-Santos+ 2007)

High resolution imaging of the early type galaxy NGC 1380: an insight into the nature of extended star clusters Chies-Santos A.L., Santiago B.X., Pastoriza M.G. <Astron. Astrophys. 467, 1003 (2007)> =2007A&A...467.1003C
ADC_Keywords: Galaxies, photometry ; Photometry, UBV ; Morphology Keywords: galaxies: individual: NGC 1380 - galaxies: star clusters Description: NGC 1380 is a lenticular galaxy located near the center of the Fornax Cluster, northeast of NGC 1399. The globular cluster system of this galaxy was previously studied only from the ground. Recent studies of similar early-type galaxies, specially lenticular ones, reveal the existence of star clusters that apparently break up the traditional open/globular cluster dichotomy. With higher quality photometry from HST/WFPC2 we study the star clusters in NGC 1380, measuring their magnitudes, colours, sizes and projected distances from the center of the galaxy. We used deep archival HST/WFPC2 in the B and V bands. We built colour magnitude diagrams from which we selected a sample of cluster candidates. We also analysed their colour distribution and measured their sizes. Based on their location in the luminosity-size diagram we estimated probabilities of them being typical globular clusters as those found in the Galaxy. A total of about 570 cluster candidates were found down to V=26.5. We measured sizes for approximately 200 of them. The observed colour distribution has three apparent peaks. Likewise for the size distribution. We identified the smaller population as being mainly typical globular clusters, while the more extended objects have small probabilities of being such objects. Different correlations between absolute magnitudes, sizes, colours and location were inferred for these cluster sub-populations. Most extended clusters (Reff>4pc) share similar properties to the diffuse star clusters reported to inhabit luminous early-type galaxies in the Virgo galaxy cluster such as being of low surface brightness and fainter than MV~-8. We also report on a small group of (Reff∼10pc), -8<MV←6, red clusters located near the centre of NGC 1380, which may be interpreted as faint fuzzies. Description: Table 4 contains positions and photometry for the resolved sample of star clusters, i.e that we could measure sizes and which have Reff<15pc. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table4.dat 84 187 *Positions and photometry for the resolved cluster sample
Note on table4.dat: Objects identified as [CSP2007] DD.ddddddd+DD.ddddddd in Simbad
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1 I1 --- Chip [1,4] HST/WFPC2 chip number 3- 9 F7.3 pix Xpos X CCD coordinate 11- 17 F7.3 pix Ypos Y CCD coordinate 19- 28 F10.7 deg RAdeg Right Ascension J2000, in decimal degrees 30- 40 F11.7 deg DEdeg Declination J2000, in decimal degrees 42- 47 F6.3 mag Vmag Johnson V magnitude 49- 53 F5.3 mag e_Vmag Mean error on Vmag 55- 60 F6.3 mag Bmag Johnson B magnitude 62- 66 F5.3 mag e_Bmag Mean error on Bmag 68- 72 F5.3 mag B-V Johnson B-V colour index 74- 78 F5.2 pc Reff Effective radius of the cluster (1) 80- 84 F5.2 pc e_Reff Mean error on Reff
Note (1): We adopted a distance modulus of (m-M)=31.4.
Acknowledgements: Ana Leonor Chies Santiago Santos, ana.leonor(at)ufrgs.br
(End) Patricia Vannier [CDS] 02-Mar-2007
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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