J/A+A/444/365 ESO Distant Cluster Survey, EDisCS (White+, 2005)
EDisCS - the ESO Distant Cluster Survey.
Sample Definition and Optical Photometry.
White S.D.M., Clowe D.I., Simard L., Rudnick G., De Lucia G.,
Aragon-Salamanca A., Bender R., Best P., Bremer M., Charlot S.,
Dalcanton J., Dantel M., Desai V., Fort B., Halliday C., Jablonka P.,
Kauffmann G., Mellier Y., Milvang-Jense B., Pello R., Poggianti B.,
Poirier S., Rottgering H., Saglia R., Schneider P., Zaritsky D.
<Astron. Astrophys. 444, 365 (2005)>
=2005A&A...444..365W 2005A&A...444..365W
ADC_Keywords: Clusters, galaxy ; Galaxies, optical ; Galaxies, photometry ;
Galaxy catalogs
Keywords: galaxies: clusters: general ; galaxies: evolution -
Abstract:
We present the ESO Distant Cluster Survey (EDisCS) a survey of 20
distant galaxy clusters with redshifts ranging from 0.4 to 0.8.
Candidate clusters were chosen from among the brightest objects
identified in the Las Campanas Distant Cluster Survey (LCDCS), half
with estimated redshift zest∼0.5 and half with zest∼0.8. They
were confirmed by identifying red sequences in moderately deep two
colour data from VLT/FORS2. For confirmed candidates we have assembled
deep three-band optical photometry using VLT/FORS2, deep near-infrared
photometry in one or two bands using NTT/SOFI, deep optical
spectroscopy using VLT/FORS2, wide field imaging in two or three bands
using the ESO Wide Field Imager, and HST/ACS mosaic images for 10 of
the most distant clusters. This first paper presents our sample and
the VLT photometry we have obtained. We present images, colour
magnitude diagrams and richness estimates for our clusters, as well as
giving redshifts and positions for the brightest cluster members.
Subsequent papers will present our infrared photometry, spectroscopy,
HST and wide-field imaging, as well as a wealth of further analysis
and science results. Our reduced data become publicly available as
these papers are accepted.
Description:
Optical photometric parameters for galaxies in the twenty EDisCS
cluster fields measured from our deep VLT/FORS2 imaging. Mid-z
clusters were observed in BVI and high-z clusters were observed in
VRI.
The catalogs contain six types of magnitude (r=1",2",3" aperture
magnitudes as well as isophotal, and total (MAG_AUTO and
MAG_AUTO+correction). The catalogs also include SExtractor
"stellarity" indices, half-light radii, ellipticities and position
angles. SExtractor version 2.2.2 was used for the EDisCS photometry.
The magnitude limits used for this catalog are mtotalI ≤ 24.0 for
mid-z clusters and mtotalI ≤ 24.5 for high-z clusters.
Zeropoint errors computed from rms dispersions in standard star
measurements are 0.018 in B, 0.013 in V, 0.013 in R and 0.016 in I.
These zeropoint errors are NOT included in the errors presented in
this catalog, and they should therefore be added in quadrature to
errors in catalog to obtain the full photometric errors.
The FORS2 filters B, V and I are close approximations to the Bessel
(1990PASP..102.1181B 1990PASP..102.1181B) photometric system while R filter is a special
filter for FORS2 (see
http://www.eso.org/instruments/fors/inst/Filters/curves.html ).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 498 40957 *Optical photometric parameters for galaxies on
EDisCS VLT/FORS2 images
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Note on catalog.dat: "***" fields mean that data were not acquired
for these fields.
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See also:
J/ApJS/137/117 : Las Campanas Distant Cluster Survey (LCDCS) (Gonzales+, 2001)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [EDCSN]
6- 21 A16 --- EDCSN EDisCS Object ID (JHHMMSSs+DDMMSSs)
23- 32 F10.6 h RAhour Object Right Ascension (J2000)
34- 43 F10.6 deg DEdeg Object Declination (J2000)
45- 51 F7.3 mag Bmagr1 ?=* FORS2 B magnitude in r=1" aperture
53- 59 F7.3 mag e_Bmagr1 ?=* B magnitude error from empty aperture
simulations in r=1" aperture (1)
61- 67 F7.3 mag Vmagr1 ?=* FORS2 V magnitude in r=1" aperture
69- 75 F7.3 mag e_Vmagr1 ?=* V magnitude error from empty aperture
simulations in r=1" aperture (1)
77- 83 F7.3 mag Rmagr1 ?=* FORS2 R magnitude in r=1" aperture
85- 91 F7.3 mag e_Rmagr1 ?=* R magnitude error from empty aperture
simulations in r=1" aperture (1)
93- 99 F7.3 mag Imagr1 ?=* FORS2 I magnitude in r=1" aperture
101-107 F7.3 mag e_Imagr1 ?=* I magnitude error from empty aperture
simulations in r=1" aperture
109-115 F7.3 mag Bmagr2 ?=* FORS2 B magnitude in r=2" aperture
117-123 F7.3 mag e_Bmagr2 ?=* B magnitude error from empty aperture
simulations in r=2" aperture (1)
125-131 F7.3 mag Vmagr2 ?=* FORS2 V magnitude in r=2" aperture
133-139 F7.3 mag e_Vmagr2 ?=* V magnitude error from empty aperture
simulations in r=2" aperture (1)
141-147 F7.3 mag Rmagr2 ?=* FORS2 R magnitude in r=2" aperture
149-155 F7.3 mag e_Rmagr2 ?=* R magnitude error from empty aperture
simulations in r=2" aperture (1)
157-163 F7.3 mag Imagr2 ?=* FORS2 I magnitude in r=2" aperture
165-171 F7.3 mag e_Imagr2 ?=* I magnitude error from empty aperture
simulations in r=2" aperture (1)
173-179 F7.3 mag Bmagr3 ?=* FORS2 B magnitude in r=3" aperture (1)
181-187 F7.3 mag e_Bmagr3 ?=* B magnitude error from empty aperture
simulations in r=3" aperture (1)
189-195 F7.3 mag Vmagr3 ?=* FORS2 V magnitude in r=3" aperture
197-203 F7.3 mag e_Vmagr3 ?=* V magnitude error from empty aperture
simulations in r=3" aperture (1)
205-211 F7.3 mag Rmagr3 ?=* FORS2 R magnitude in r=3" aperture
213-219 F7.3 mag e_Rmagr3 ?=* R magnitude error from empty aperture
simulations in r=3" aperture (1)
221-227 F7.3 mag Imagr3 ?=* FORS2 I magnitude in r=3" aperture
229-235 F7.3 mag e_Imagr3 ?=* I magnitude error from empty aperture
simulations in r=3" aperture (1)
237-243 F7.3 mag Bmagiso ?=* FORS2 B isophotal magnitude
245-251 F7.3 mag e_Bmagiso ?=* B isophotal magnitude error from empty
aperture simulations (1)
253-259 F7.3 mag Vmagiso ?=* FORS2 V isophotal magnitude
261-267 F7.3 mag e_Vmagiso ?=* V isophotal magnitude error from empty
aperture simulations (1)
269-275 F7.3 mag Rmagiso ?=* R isophotal magnitude
277-283 F7.3 mag e_Rmagiso ?=* R isophotal magnitude error from empty
aperture simulations (1)
285-291 F7.3 mag Imagiso ?=* FORS2 I isophotal magnitude
293-299 F7.3 mag e_Imagiso ?=* I isophotal magnitude error from empty
aperture simulations
301-307 F7.3 mag Bmagauto ?=* FORS2 B auto magnitude
309-315 F7.3 mag e_Bmagauto ?=* B auto magnitude error from empty
aperture simulations (1)
317-323 F7.3 mag Vmagauto ?=99.000 FORS2 V auto magnitude
325-331 F7.3 mag e_Vmagauto ?=* V auto magnitude error from empty
aperture simulations (1)
333-339 F7.3 mag Rmagauto ?=* R auto magnitude
341-347 F7.3 mag e_Rmagauto ?=* R auto magnitude error from empty
aperture simulations (1)
349-355 F7.3 mag Imagauto ?=* FORS2 I auto magnitude
357-363 F7.3 mag e_Imagauto ?=* I auto magnitude error from empty
aperture simulations
365-371 F7.3 mag Iapcorrr Point source aperture corrections (2)
373-379 F7.3 mag Imagtot ?=* FORS2 I total magnitude (3)
381-387 F7.3 mag e_Imagtot ?=* I total magnitude error from empty
aperture simulations
389-392 I4 --- Bflg ?=* B SExtractor object flag
394-397 I4 --- Vflg V SExtractor object flag
399-402 I4 --- Rflg ?=* R SExtractor object flag
404-407 I4 --- Iflg I SExtractor object flag
409-412 F4.2 --- Bst ?=* B SExtractor "Stellarity" index (1=star)
414-417 F4.2 --- Vst V SExtractor "Stellarity" index (1=star)
419-422 F4.2 --- Rst ?=* R SExtractor "Stellarity" index (1=star)
424-427 F4.2 --- Ist I SExtractor "Stellarity" index (1=star)
429-434 F6.2 arcsec Bhlr ?=* Object B SExtractor
half-light radius (4) (1)
436-441 F6.2 arcsec Vhlr Object V SExtractor half-light radius (4) (1)
443-448 F6.2 arcsec Rhlr ?=* Object R SExtractor
half-light radius (4) (1)
450-455 F6.2 arcsec Ihlr Object I SExtractor half-light radius (4)
457-460 F4.2 --- Iell I SExtractor object ellipticity (0=circular)
462-468 F7.2 deg Ipa I SExtractor object position angle
(CCW from image x-axis)
470-475 F6.2 arcsec Ia I SExtractor object semi-major axis
477-482 F6.2 arcsec Ib I SExtractor object semi-minor axis
484-489 F6.2 arcsec Irkron I SExtractor object Kron radius
491-497 F7.2 arcsec2 IisoA I SExtractor object isophotal area (5)
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Note (1): When the magnitude for an object given by SExtractor in a given
band was fainter than the 1-sigma magnitude limit measured from the
empty aperture simulations, this magnitude was replaced by the 1-sigma
limit and the corresponding magnitude error was set to 99.000. All
magnitudes with 99.000 error values are therefore 1-sigma limits. Note
that if e_?magauto is 99.000, then the value given by SExtractor for
the object half-light radius cannot be trusted. Therefore, the
half-light radius was also set to 99.000 for these cases.
Note (2): Used to convert auto magnitudes to the "total" magnitudes.
These were derived on an image-by-image basis using the curves of
growth of unsaturated and uncrowd ed stars.
Note (3): Imagtot = Imagauto + Iapcorr
Note (4): SExtractor "FLUX_RADIUS" parameter.
Note (5): Minimum possible value was set to 0".70 (3.5 pixels) in
SExtractor parameter configuration.
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Acknowledgements: Luc Simard,
(End) Luc Simard [NRC-HIA], Patricia Vannier [CDS] 23-Aug-2005