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J/A+A/455/453       Globular Cluster System of NGC5846     (Chies-Santos+, 2006)

The globular cluster system of NGC 5846 revisited: colours, sizes and X-ray counterparts. Chies-Santos A.L., Pastoriza M.G., Santiago B.X., Forbes D.A. <Astron. Astrophys. 455, 453 (2006)> =2006A&A...455..453C
ADC_Keywords: Clusters, globular ; X-ray sources ; Photometry, HST Keywords: Galaxies: individual: NGC 5846 - galaxies: star clusters - X-rays: galaxies Abstract: NGC 5846 is a giant elliptical galaxy with a previously well studied globular cluster system (GCS), known to have a bimodal colour distribution with a remarkably high red fraction. Here we revisit the central galaxy regions searching for new globular cluster (GC) candidates, and measure magnitudes, colours and sizes for them. We also search for their X-ray counterparts. Methods: We use archival Hubble Space Telescope WFPC2 images, from which we modelled and subtracted the host light distribution to increase the available sample of GCs. We performed photometry on the central objects, and measured sizes and coordinates for the entire GC system known in this galaxy. Results: We detect two dozen previously unknown GC candidates in the central reg ions. Reliable sizes are obtained for about 60 GCs; their typical effective radii are in the range 3-5pc. The largest clusters are located in the central regions. We find 7 X-ray counterparts to GCs, most of them in the central region. They are among the most luminous X-ray sources in NGC 5846. They are also optically luminous, compact and belong to the red subpopulation. Conclusions: The GCS of NGC 5846 is composed of relatively luminous X-ray sources. Description: Table. 3 contains positions and photometry of the entire GCS of NGC 5846; Table 4. lists the sizes and related parameters for those GCs which were success fully measured by ISHAPE code (Larsen, 1999A&AS..139..393L). File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3.dat 71 777 Positions and photometry for the entire GCS of NGC 5846 table4.dat 49 54 Sizes and related parameters for GCs successfully measured by ISHAPE
See also: J/AJ/130/1502 : NGC 5846 group: photometry and spectroscopy (Mahdavi+, 2005) Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1 A1 --- Pointing [CNS] HST/WFPC2 pointing Central, North or South 3 I1 --- Chip [1/4] HST/WFPC2 chip number 5- 10 F6.2 pix Xpix X CCD coordinate 12- 17 F6.2 pix Ypix Y CCD coordinate 19- 29 F11.7 deg RAdeg Right ascension in decimal degrees (J2000) 31- 39 F9.7 deg DEdeg Declination in decimal degrees (J2000) 41- 45 F5.2 mag Vmag V magnitude (F555W) 47- 50 F4.2 mag e_Vmag rms uncertainty on Vmag 52- 56 F5.2 mag Imag I magnitude (F814W) 58- 61 F4.2 mag e_Imag rms uncertainty on Imag 63- 66 F4.2 mag V-I V-I colour index (F555W-F814W) 68- 71 F4.2 mag e_V-I rms uncertainty on V-I
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 11 F11.7 deg RAdeg Right ascension in decimal degrees (J2000) 13- 21 F9.7 deg DEdeg Declination in decimal degrees (J2000) 23- 27 F5.2 mag Vmag V magnitude (F555W) 29- 33 F5.2 mag Imag I magnitude (F814W) 35- 38 F4.2 mag V-I V-I colour index (F555W-F814W) 40- 44 F5.2 pc Reff Effective radius 46- 49 F4.2 --- chiratio chi ratio (chi2/chi02)
Acknowledgements: Ana Leonor Chies Santiago Santos, ana.leonor(at)
(End) Patricia Vannier [CDS] 19-May-2006
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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