J/A+A/600/A110 VIMOS Ultra Deep Survey (VUDS) DR1 (Tasca+, 2017)
The VIMOS Ultra Deep Survey first data release:
Spectra and spectroscopic redshifts of 698 objects up to zspec ∼ 6 in CANDELS.
Tasca L.A.M., Le Fevre O., Ribeiro B., Thomas R., Moreau C., Cassata P.,
Garilli B., Le Brun V., Lemaux B.C., Maccagni D., Pentericci L.,
Schaerer D., Vanzella E., Zamorani G., Zucca E., Amorin R., Bardelli S.,
Cassara L.P., Castellano M., Cimatti A., Cucciati O., Durkalec A.,
Fontana A., Giavalisco M., Grazian A., Hathi N.P., Ilbert O., Paltani S.,
Pforr J., Scodeggio M., Sommariva V., Talia M., Tresse L., Vergani D.,
Capak P., Charlot S., Contini T., de la Torre S., Dunlop J., Fotopoulou S.,
Guaita L., Koekemoer A., Lopez-Sanjuan C., Mellier Y., Salvato M.,
Scoville N., Taniguchi Y., Wang P.W.
<Astron. Astrophys., 600, A110 (2017)>
=2017A&A...600A.110T 2017A&A...600A.110T (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Galaxy catalogs ; Redshifts
Keywords: galaxies: distances and redshifts - galaxies: high-redshift -
cosmology: observations - surveys - catalogs
Abstract:
This paper describes the first data release (DR1) of the VIMOS Ultra
Deep Survey (VUDS). The VUDS-DR1 is the release of all low-resolution
spectroscopic data obtained in 276.9 arcmin2 of the CANDELS-COSMOS
and CANDELS-ECDFS survey areas, including accurate spectroscopic
redshifts zspec and individual spectra obtained with VIMOS on the
ESO-VLT. A total of 698 objects have a measured redshift, with 677
galaxies, two type-I AGN, and a small number of 19 contaminating
stars. The targets of the spectroscopic survey are selected primarily
on the basis of their photometric redshifts to ensure a broad
population coverage. About 500 galaxies have zspec>2, 48of which
have zspec>4; the highest reliable redshifts reach beyond zspec=6.
This data set approximately doubles the number of galaxies with
spectroscopic redshifts at z>3 in these fields. We discuss the general
properties of the VUDS-DR1 sample in terms of the spectroscopic
redshift distribution, the distribution of Lyman-α equivalent
widths, and physical properties including stellar masses M* and star
formation rates derived from spectral energy distribution fitting with
the knowledge of zspec. We highlight the properties of the most
massive star-forming galaxies, noting the wide range in spectral
properties, with Lyman-α in emission or in absorption, and in
imaging properties with compact, multi-component, or pair
morphologies. We present the catalogue database and data products. All
VUDS-DR1 data are publicly available and can be retrieved from a
dedicated query-based database. Future VUDS data releases will follow
this VUDS-DR1 to give access to the spectra and associated measurement
of ∼8000 objects in the full ∼1 square degree of the VUDS survey.
Description:
The VIMOS Ultra Deep Survey is a spectroscopic survey targeting
∼10000 galaxies to study galaxy evolution in the redshift range
2<z<6+. We provide a summary of the survey below and the reader is
referred to Le Fevre et al. (2015A&A...576A..79L 2015A&A...576A..79L) for a detailed
description.
Multi-slit spectroscopy is conducted with the VIsible Multi-Object
Spectrograph (VIMOS) on the ESO-VLT unit number 3 "Melipal". Each
VIMOS pointing is observed for about 14h in the LRBLUE grism with a
wavelength coverage from 3600 to 6700Å, and another 14h with the
LRRED grism covering 5500 to 9350Å. Each of the LRBLUE and LRRED
observations cumulates about 40 individual exposures of ∼20min
integrations each. To remove most of the small-scale detector pattern,
the telescope is offset between each exposure to move objects along
the slits with a repeated offset pattern -1.0, -0.5, 0, +0.5, +1.0
arcsecond from the nominal pointing position.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cosmos.dat 129 384 VUDS-DR1 COSMOS field
ecdfs.dat 129 314 VUDS-DR1 ECDFS field
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See also:
http://cesam.lam.fr/vuds/DR1 : VUDS-DR1 home page
Byte-by-byte Description of file: cosmos.dat
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Bytes Format Units Label Explanations
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1- 10 I10 --- VUDS [510253764/5181466520] VUDS number
12- 23 F12.8 deg RAdeg [150.051/150.207] Right ascension (J2000)
25- 34 F10.8 deg DEdeg [2.17433/2.55702] Declination (J2000)
36- 42 A7 --- Mask Mask used for spectroscopic observation
44 I1 --- quad [1/4] Quadran number
46- 48 I3 --- slit [1/128] Slit number
50 I1 --- obj [1/3] Object number
52- 53 A2 --- det [OK] Detection flag
55- 61 F7.3 --- Fmean [-0.446/413.058] Mean flux in the overlap
wavelength range 5500-6700Å
63- 67 F5.3 --- sn [0/7.126] Signal-to-noise ratio
69- 73 F5.3 --- maxdel [0.19/3.139] maxdel value
75- 79 F5.3 --- rmsdel [0.108/1.396] rmsdel value
81- 86 F6.4 --- zspec [0/6.4418] Spectroscopic redshift
88- 89 I2 --- zflags [1/39] Spectroscopic redshift reliability flag
(3 or 4 = secure) (G1)
91-114 A24 --- IAUID IAU name (VUDS-JHHMMSS.ss+DDMMSS.s)
116-120 I5 --- CANDELS [4/36576]?=- CANDELS ID
124-129 F6.3 --- imag [18.444/26.746]? i magnitude (AB)
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Byte-by-byte Description of file: ecdfs.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- VUDS [530016323/539990803] VUDS number
11- 21 F11.8 deg RAdeg [53.0019/53.2582] Right ascension (J2000)
23- 34 F12.8 deg DEdeg [-27.9583/-27.6632] Declination (J2000)
36- 42 A7 --- Mask Mask used for spectroscopic observation
44 I1 --- quad [1/4] Quadran number
46- 48 I3 --- slit [1/145] Slit number
50 I1 --- obj [1/3] Object number
52- 53 A2 --- det [OK] Detection flag
55- 60 F6.3 --- Fmean [-1.62/21.699] Mean flux in the overlap
wavelength range 5500-6700Å
62- 66 F5.3 --- sn [0/7.311] Signal-to-noise ratio
68- 72 F5.3 --- maxdel [0.464/2.714] maxdel value
74- 78 F5.3 --- rmsdel [0.237/1.374] rmsdel value
80- 85 F6.4 --- zspec [0/6.0912] Spectroscopic redshift
87- 88 I2 --- zflags [1/44] Spectroscopic redshift reliability flag
(3 or 4 = secure) (G1)
90- 98 F9.5 --- imag [0/29.23]?=-99 i magnitude (AB)
100-123 A24 --- IAUID IAU name (VUDS-JHHMMSS.ss+DDMMSS.s)
125-129 I5 --- CANDELS [6/26986]?=- CANDELS ID
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Global notes:
Note (G1): VUDS redshift reliability flags as follows:
4 = 100% reliability, high S/N with many absorption and/or emission lines;
strong cross-correlation signal with excellent continuum match to
templates
3 = 95-100% reliability, moderate to high S/N with several absorption
and/or emission lines; strong cross-correlation signal with good to
excellent continuum match to templates
2 = 70-80% reliability, moderate S/N with matching absorption and/or
emission lines; good cross-correlation signal
1 = 40-50% reliability, low S/N lines or continuum; weak to moderate
cross-correlation signal
9 = 80% reliability, single emission line spectrum; the line has moderate
to high S/N. Redshift is assigned based on the exclusion of
alternative solutions in the absence of other expected key features
1X = Like flag X but spectral features indicate the presence of an AGN
2X = Like flag X but for a secondary target falling in the slit of a primary
3X = Like flag X but the spectrum shows two line systems at different
redshifts, the highest of the two redshifts is given as zspec
4X = Like flag X but the two spectra are close in velocity indicative of a
physical pair
-2X = Like flag X but for a secondary target falling in the slit of a primary
but not present in the photometric parent catalogue
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History:
Copied at http://cesam.lam.fr/vuds/DR1
(End) Patricia Vannier [CDS] 15-Mar-2018