J/A+A/391/945 HST photometry of 74 galactic globular clusters (Piotto+, 2002)
HST color-magnitude diagrams of 74 galactic globular clusters in the
HST F439W and F555W bands.
Piotto G., King I.R., Djorgovski S.G., Sosin C., Zoccali M., Saviane I.,
de Angeli F., Riello M., Recio-Blanco A., Rich R.M., Meylan G., Renzini A.
<Astron. Astrophys. 391, 945 (2002)>
=2002A&A...391..945P 2002A&A...391..945P
ADC_Keywords: Clusters, globular ; Photometry ; Abundances, [Fe/H]
Mission_Name: HST
Keywords: stars: evolution - stars: C-M diagrams - stars: Population II -
Galaxy: globular clusters: general
Abstract:
We present the complete photometric database and the color-magnitude
diagrams for 74 Galactic globular clusters observed with the HST/WFPC2
camera in the F439W and F555W bands. A detailed discussion of the
various reduction steps is also presented, and of the procedures to
transform instrumental magnitudes into both the HST F439W and F555W
flight system and the standard Johnson B and V systems. We also
describe the artificial star experiments which have been performed to
derive the star count completeness in all the relevant branches of the
color magnitude diagram. The entire photometric database and the
completeness function will be made available on the Web immediately
after the publication of the present paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 94 74 Main parameters of the observed clusters
db/* . 74 Photometric database (1 file per cluster)
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See also:
VII/151 : Structure Parameters of Galactic Globular Clusters (Webbink 1985)
VII/202 : Globular Clusters in the Milky Way (Harris, 1997)
http://dipastro.pd.astro.it/globulars/databases/snapshot : Paper Home Page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- NGC/IC Cluster NGC or IC name
10- 16 A7 --- Name Other cluster name
18- 23 F6.2 deg GLON Galactic longitude
25- 30 F6.2 deg GLAT Galactic latitude
32- 35 F4.1 kpc RGC Distance from the Galactic center,
assuming R0=8.0kpc
37- 40 F4.2 mag E(B-V) Foreground reddening
42- 46 F5.2 mag (m-M)V Apparent visual distance modulus
48- 52 F5.2 mag VMAG Absolute visual magnitude
54- 58 F5.2 [Sun] [Fe/H] Metallicity
60- 63 F4.2 --- c ? Central concentration (c=log(rt/rc))
64 A1 --- n_c [c] c: core-collapsed cluster
65 A1 --- u_c Uncertainty flag on c
67- 71 F5.2 [yr] logrt ? logarithm of relaxation time
73- 76 F4.2 [yr] logtc ? logarithm of core relaxation time
78- 82 F5.2 [yr] logth ? logarithm of relaxation time at
the half-mass radius
84- 87 F4.2 [solLum/pc3] logρ0 ? logarithm of central luminosity density
89- 94 A6 --- CMD Link to color-magnitude diagram,
at the Padova Globular Cluster Group Web
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Byte-by-byte Description (# are comments) of file: db/*
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID Running number on the chip
8- 14 F7.3 pix Xpos Position on the chip along X-axis
16- 22 F7.3 pix Ypos Position on the chip along Y-axis
24- 30 F7.4 mag Vmag ? Johnson V magnitude, reddening corrected (1)
32- 38 F7.4 mag Bmag ? Johnson B magnitude, reddening corrected (1)
40- 46 F7.4 mag F555W ? HST F555W magnitude, reddening corrected (1)
48- 54 F7.4 mag F439W ? HST F439W magnitude, reddening corrected (1)
56- 61 F6.4 mag e_F555W Photometric error on F555W
63- 68 F6.4 mag e_F439W Photometric error on F555W
70- 76 F7.4 mag Vmag.nr ? Johnson V before dereddening (1)
78- 84 F7.4 mag Bmag.nr ? Johnson B before dereddening (1)
86- 92 F7.4 mag F555Wnr HST F555W before dereddening
94-100 F7.4 mag F439Wnr HST F439W before dereddening
102-108 F7.4 mag chi chi fit parameter
110-117 F8.4 mag sharp sharp parameter (2)
119 I1 --- chip [1,4] Chip number (3)
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Note (1):
A few values largely outside the acceptable range (e.g. ←50)
have been replaced by blanks.
Note (2):
The sharp parameter is significantly positive for
non-stellar objects as semi-resolved galaxies and unrecognized
blended double stars, and significantly negative
for cosmic rays.
Stellar objects have the sharp parameter in the
[-0.2-+0.2] range.
Note (3): the chip#1 is the planetary camera (PC),
chips 2, 3 and 4 are Wide Fields 1, 2 and 3 respectively.
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History:
* 08-Oct-2002: Copied at http://dipastro.pd.astro.it
* 16-Nov-2006: 6 out of the 7 first rows of table2 had an erroneous
galactic latitude, corrected here.
(End) Patricia Bauer [CDS] 08-Oct-2002