J/ApJ/642/L13 ECDFS MUSYC galaxies UBVRIzNB5000 photometry (Gawiser+, 2006)
The physical nature of Lyα-emitting galaxies at z=3.1.
Gawiser E., van Dokkum P.G., Gronwall C., Ciardullo R., Blanc G.A.,
Castander F.J., Feldmeier J., Francke H., Franx M., Haberzettl L.,
Herrera D., Hickey T., Infante L., Lira P., Maza J., Quadri R.,
Richardson A., Schawinski K., Schirmer M., Taylor E.N., Treister E.,
Urry C.M., Virani S.N.
<Astrophys. J., 642, L13-L16 (2006)>
=2006ApJ...642L..13G 2006ApJ...642L..13G
ADC_Keywords: Surveys ; Galaxies, photometry ; Photometry, UBVRI ;
Photometry, narrow-band
Keywords: galaxies: high-redshift
Abstract:
We selected 40 candidate Lyα-emitting galaxies (LAEs) at z∼3.1
with observed-frame equivalent widths greater than 150Å and
inferred emission-line fluxes above 2.5x10-17ergs/cm2/s from deep
narrowband and broadband MUSYC images of the Extended Chandra Deep
Field South. Covering 992-arcmin2, this is the largest "blank field"
surveyed for LAEs at z∼3, allowing an improved estimate of the space
density of this population of (3±1)x104h/Mpc3. Spectroscopic
follow-up of 23 candidates yielded 18 redshifts, all at z∼3.1. Over
80% of the LAEs are dimmer in continuum magnitude than the typical
Lyman break galaxy (LBG) spectroscopic limit of R=25.5 (AB), with a
median continuum magnitude R∼27 and very blue continuum colors,
V-z~=0.
Description:
Our narrowband imaging of the ECDF-S was obtained using the narrowband
5000Å filter (NB5000; 50Å FWHM) with the CTIO 4m telescope and
MOSAIC II on several nights from 2002 to 2004 for a total of 29hr of
exposure time.
Our UBVRI imaging results from combining public images taken with the
ESO 2.2m and WFI by the ESO Deep Public Survey and COMBO-17 teams.
Our z' imaging was taken with the CTIO 4m and MOSAIC II on 2005
January 15. Our JK images of the ECDF-S were obtained with the CTIO 4m
and ISPI on several nights during 2003-2004
Images and other information available at www.astro.yale.edu/MUSYC;
see Gawiser et al. 2007, Cat. J/ApJS/162/1 for full description
including detailed definition and simulation of APCORR photometry
method. No psf-matching was performed as we seek high S/N for small
objects AUTO and APCORR both estimate total fluxes, AUTO via Kron
elliptical aperture, and APCORR via small ∼FWHM-sized apertures plus
correction based on half-light radius and curve-of-growth measured for
point sources. AUTO slightly underestimates total fluxes, APCORR is
unbiased, APCORR offers higher S/N but is less robust for highly
extended sources. Corrected for Galactic extinction of E(B-V)=0.01
(Schlegel et al., 1998ApJ...500..525S 1998ApJ...500..525S). Flux densities are in microJy
and correspond to an AB zeropoint of 23.9:
magAB=-2.5*log10(flux)+23.9
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
nbdetzo3.dat 715 28297 MUSYC ECDF-S, NB5000(=o3)-detected catalog with
UBVRIzo3 photometry, V1, 2005/15/10
ubvrizo3.dat 715 84410 MUSYC ECDF-S, BVR-detected catalog with
UBVRIzo3 photometry, V1, 2005/15/10
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See also:
J/ApJS/189/270 : MUSYC optical imaging in ECDF-S (Cardamone+, 2010)
Byte-by-byte Description of file: nbdetzo3.dat ubvrizo3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Seq [0/884409] Sequential number (1)
7- 15 F9.7 h RAhour Right ascension in decimal hours (J2000),
BVR detection image
17- 26 F10.6 deg DEdeg Declination in decimal degrees (J2000),
BVR detection image
28- 37 F10.5 pix X X barycenter (BVR detection image)
39- 48 F10.5 pix Y Y barycenter (BVR detection image)
50- 57 F8.6 --- S/G [0/1] SExtractor star/galaxy classifier
(0=Galaxy, 1=Star; BVR detection image)
59- 70 F12.7 arcsec Rhl Halflight radius
72- 83 F12.7 arcsec A Flux distribution rms along major axis
85- 96 F12.7 arcsec B Flux distribution rms along minor axis
98-108 F11.7 deg theta Position angle counterclockwise from x-axis
110-124 F15.8 uJy Fopt BVR AUTO Sextractor flux
126-137 F12.8 uJy e_Fopt Uncertainty in flux
139-154 F16.9 uJy FU U AUTO Sextractor flux
156-170 F15.10 uJy e_FU Uncertainty in FU
172-187 F16.9 uJy FB B AUTO Sextractor flux
189-203 F15.10 uJy e_FB Uncertainty in FB
205-220 F16.9 uJy FV V AUTO Sextractor flux
222-236 F15.10 uJy e_FV Uncertainty in FV
238-253 F16.9 uJy FR R AUTO Sextractor flux
255-269 F15.10 uJy e_FR Uncertainty in FR
271-286 F16.9 uJy FI I AUTO Sextractor flux
288-302 F15.10 uJy e_FI Uncertainty in FI
304-319 F16.9 uJy Fz z AUTO Sextractor flux
321-335 F15.10 uJy e_Fz Uncertainty in Fz
337-352 F16.9 uJy Fo3 NB5000 (o3) AUTO Sextractor flux (3)
354-368 F15.10 uJy e_Fo3 Uncertainty in Fo3
370-385 F16.9 uJy Foptap BVR corrected aperture (APCORR) Sextractor flux
387-404 E18.9 uJy e_Foptap Uncertainty in fluxap
406-421 F16.9 uJy FUap U corrected aperture (APCORR) Sextractor flux
423-440 E18.9 uJy e_FUap Uncertainty in FUap
442-457 F16.9 uJy FBap B corrected aperture (APCORR) Sextractor flux
459-476 E18.9 uJy e_FBap Uncertainty in FBap
478-493 F16.9 uJy FVap V corrected aperture (APCORR) Sextractor flux
495-514 E20.9 uJy e_FVap Uncertainty in FVap
516-531 F16.9 uJy FRap R corrected aperture (APCORR) Sextractor flux
533-552 E20.9 uJy e_FRap Uncertainty in FRap
554-569 E16.9 uJy FIap I corrected aperture (APCORR) Sextractor flux
571-592 E22.9 uJy e_FIap Uncertainty in FIap
594-609 E16.9 uJy Fzap z corrected aperture (APCORR) Sextractor flux
611-633 E23.9 uJy e_Fzap Uncertainty in Fzap
635-650 F16.9 uJy Fo3ap NB5000 (o3) corrected aperture (APCORR) (3)
Sextractor flux
652-671 E20.9 uJy e_Fo3ap Uncertainty in Fo3ap
673-674 I2 --- f.opt SExtractor flags for BVR (2)
676-677 I2 --- f.U SExtractor flags for U (2)
679-680 I2 --- f.B SExtractor flags for B (2)
682-683 I2 --- f.V SExtractor flags for V (2)
685-686 I2 --- f.R SExtractor flags for R (2)
688-689 I2 --- f.I SExtractor flags for I (2)
691-692 I2 --- f.Z SExtractor flags for z (2)
694-695 I2 --- f.o3 SExtractor flags for o3 (2)
697-715 A19 --- MUSYC Object MUSYC name (JHHMMSS.ss+DDMMSS.s)
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Note (1): Sources identified as
<[GVG2006] NB NNNNN> for nbdetzo3.dat catalog,
<[GVG2006] BRV NNNNN> for ubvrizo3.dat catalog.
Note (2): SExtractor flag FLAGS contain, coded in additive numbers, 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 object 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
Note (3): NB5000 is a narrow-band filter centered at λ=500nm
with a FWHM=5nm.
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History:
Copied at http://www.astro.yale.edu/MUSYC/ecdfs/optical/
(End) Patricia Vannier [CDS] 19-Apr-2012