J/A+A/497/667 WINGS: Deep optical phot. of 77 nearby clusters (Varela+, 2009)
WINGS: A WIde-field Nearby Galaxy-cluster Survey.
II. Deep optical photometry of 77 nearby clusters.
Varela J., D'Onofrio M., Marmo C., Fasano G., Bettoni D., Cava A.,
Couch W. J., Dressler A., Kjaergaard P., Moles M., Pignatelli E.,
Poggianti B. M., Valentinuzzi T.
<Astron. Astrophys. 497, 667 (2009)>
=2009A&A...497..667V 2009A&A...497..667V
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry
Keywords: galaxies: clusters: general - catalogs
Abstract:
This is the second paper of a series devoted to the WIde Field Nearby
Galaxy-cluster Survey (WINGS). WINGS is a long term project which is
gathering wide-field, multi-band imaging and spectroscopy of galaxies
in a complete sample of 77 X-ray selected, nearby clusters (0.04<z<0.07)
located far from the galactic plane (|b|>200deg). The main goal of
this project is to establish a local reference for evolutionary
studies of galaxies and galaxy clusters. This paper presents the
optical (B,V) photometric catalogs of the WINGS sample and describes
the procedures followed to construct them. We have paid special care
to correctly treat the large extended galaxies (which includes the
brightest cluster galaxies) and the reduction of the influence of the
bright halos of very bright stars. We have constructed photometric
catalogs based on wide-field images in B and V bands using SExtractor.
Photometry has been performed on images in which large galaxies and
halos of bright stars were removed after modeling them with elliptical
isophotes. We publish deep optical photometric catalogs (90% complete
at V21.7, which translates to ∼ MV* + 6 at mean redshift), giving
positions, geometrical parameters, and several total and aperture
magnitudes for all the objects detected. For each field we have
produced three catalogs containing galaxies, stars and objects of
"unknown" classification (∼16%). From simulations we found that the
uncertainty of our photometry is quite dependent of the light profile
of the objects with stars having the most robust photometry and de
Vaucouleurs profiles showing higher uncertainties and also an
additional bias of ~-0.2m. The star/galaxy classification of the
bright objects (V<20) was checked visually making negligible the
fraction of misclassified objects. For fainter objects, we found that
simulations do not provide reliable estimates of the possible
misclassification and therefore we have compared our data with that
from deep counts of galaxies and star counts from models of our
Galaxy. Both sets turned out to be consistent with our data within ∼5%
(in the ratio galaxies/total) up to V∼24. Finally, we remark that the
application of our special procedure to remove large halos improves
the photometry of the large galaxies in our sample with respect to the
use of blind automatic procedures and increases (∼16%) the detection
rate of objects projected onto them.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tabled3.dat 52 77 Coordinates of the emission peak of the
brightest cluster galaxies (BCG)
gal/* . 77 Datafiles for galaxies in the field of each Cluster
(files named Cluster_G.dat)
star/* . 77 Datafiles for stars in the field of each Cluster
(files named Cluster_S.dat)
unkno/* . 77 Datafiles for objects of unknown type in each
field of the Cluster (files named Cluster_U.dat)
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See also:
J/A+A/495/707 : WINGS spectroscopy of 48 galaxy clusters (Cava+, 2009)
Byte-by-byte Description of file: tabled3.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Cluster Cluster name
9- 10 I2 h RAh Brightest galaxy right ascension (J2000.0)
12- 13 I2 min RAm Brightest galaxy right ascension (J2000.0)
15- 18 F4.1 s RAs Brightest galaxy right ascension (J2000.0)
21 A1 --- DE- Brightest galaxy declination sign (J2000.0)
22- 23 I2 deg DEd Brightest galaxy declination (J2000.0)
25- 26 I2 arcmin DEm Brightest galaxy declination (J2000.0)
28- 31 F4.1 arcsec DEs Brightest galaxy declination (J2000.0)
34- 52 A19 --- SName Simbad name of the cluster
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Byte-by-byte Description of file: gal/* star/* unkno/*
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [WINGS]
6- 25 A20 --- WINGS Object identification,
JHHMMSS.ss+DDMMSS.s (1)
27- 35 F9.5 deg RAdeg Right Ascention J2000.0, Barycentre
37- 45 F9.5 deg DEdeg Declination J2000.0, Barycentre
47- 55 F9.5 deg RApdeg Right Ascention J2000.0, Emission peak
57- 65 F9.5 deg DEpdeg Declination J2000.0, Emission peak
67- 74 F8.2 arcsec+2 Area Isophotal area
76- 81 F6.2 arcsec KronRad Kron radius
83- 88 F6.2 arcsec FWHM Full width at half maximum
90- 93 F4.2 -- b/a Ratio between minor axis and major axis
95- 97 I3 deg PA [-90/90] Position angle (North=0, Eastwards)
99-101 I3 -- Flag SExtractor's flags (2)
103-106 F4.2 -- SI [0/1] SExtractor's Stellarity Index
(0=galaxy; 1=star)
108-113 F6.3 -- Conc Concentration parameter (3)
115-120 F6.3 -- Contr Contrast parameter (4)
122-126 F5.2 mag/arcsec2 mumax Surface brightness of the emission peak
128-132 F5.2 mag Viso ?=99 SExtractor's MAG_ISO in V band (5)
134-138 F5.2 mag Visoc ?=99 SExtractor's MAG_ISOCOR in V band (5)
140-144 F5.2 mag Vauto ?=99 SExtractor's MAG_AUTO in V band (5)
146-150 F5.2 mag V2kpc ?=99 V magnitude in aperture of r=2kpc (5)(6)
152-156 F5.2 mag V5kpc ?=99 V magnitude in aperture of r=5kpc (5)(6)
158-162 F5.2 mag V10kpc ?=99 V magnitude in aperture of r=10kpc(5)(6)
164-168 F5.2 mag Vfib1 ?=99 V magnitude in aperture of r=1.6" (5)
170-174 F5.2 mag Vfib2 ?=99 V magnitude in aperture of r=2.0" (5)
176-180 F5.2 mag Vfib3 ?=99 V magnitude in aperture of r=2.16"(5)
182-186 F5.2 mag Biso ?=99 SExtractor's MAG_ISO in B band (5)
188-192 F5.2 mag Bisoc ?=99 SExtractor's MAG_ISOCOR in B band (5)
194-198 F5.2 mag Bauto ?=99 SExtractor's MAG_AUTO in B band (5)
200-204 F5.2 mag B2kpc ?=99 B magnitude in aperture of r=2kpc (5)(6)
206-210 F5.2 mag B5kpc ?=99 B magnitude in aperture of r=5kpc (5)(6)
212-216 F5.2 mag B10kpc ?=99 B magnitude in aperture of r=10kpc(5)(6)
218-222 F5.2 mag Bfib1 ?=99 B magnitude in aperture of r=1.6" (5)
224-228 F5.2 mag Bfib2 ?=99 B magnitude in aperture of r=2.0" (5)
230-234 F5.2 mag Bfib3 ?=99 B magnitude in aperture of r=2.16"(5)
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Note (1): The object identification contains the coordinates of the most
probable centre. For objects brighter than V=17 the peak of emission
has been chosen while for fainter objects the barycentre position was
chosen.
Note (2): SExtractor's flags meaning from SExtractor User's Manual 2.4.
FLAGS contains, coded in decimal, all the extraction flags as a sum
of powers of 2:
1 = The object has neighbours, bright and close enough to significantly
bias the MAG AUTO photometry, or bad pixels (more than 10% of the
integrated area affected),
2 = The object was originally blended with another one,
4 = At least one pixel of the ob ject is saturated (or very close to),
8 = The object is truncated (too close to an image boundary),
16 = Object's aperture data are incomplete or corrupted,
32 = Object's isophotal data are incomplete or corrupted,
64 = A memory overflow occurred during deblending,
128 = A memory overflow occurred during extraction.
For example, an object close to an image border may have FLAGS=16,
and perhaps FLAGS=8+16+32 = 56.
Note (3): The concentration given is the ratio between the flux of the 9%
central pixels and the total flux,
Note (4): The contrast given is the ratio between the flux of the 30%
brightest pixels and the total flux.
Note (5): Magnitudes are not corrected by galactic extinction.
Note (6): The radius in kpc are computed at the distance of the target cluster.
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Acknowledgements:
Jesus Varela, jesus.varela.lopez(at)mail.com
References:
Fasano et al., Paper I. 2006A&A...445..805F 2006A&A...445..805F
Varela et al., Paper II. 2009A&A...497..667V 2009A&A...497..667V
Valentnuzzi et al., Paper III. 2009arXiv0902.0954V 2009arXiv0902.0954V
Cava el al., Spectroscopy 2009A&A...495..707C 2009A&A...495..707C
(End) Patricia Vannier [CDS] 14-May-2009