J/AJ/128/1 First Look Survey: NOAO R-band Mosaic (Fadda+, 2004)
The Spitzer Space Telescope First-Look Survey: KPNO Mosaic-1 R-band images and
source catalogs.
Fadda D., Jannuzi B.T., Ford A., Storrie-Lombardi L.J.
<Astron. J., 128, 1-15 (2004)>
=2004AJ....128....1F 2004AJ....128....1F
ADC_Keywords: Galaxies, photometry
Keywords: catalogs - galaxies: photometry
Abstract:
We present R-band images covering more than 11 square degrees of sky
that were obtained in preparation for the Spitzer Space Telescope
First-Look Survey (FLS). The FLS was designed to characterize the
mid-infrared sky at depths 2 orders of magnitude deeper than previous
surveys. The extragalactic component is the first cosmological survey
done with Spitzer. Source catalogs extracted from the R-band images
are also presented. The R-band images were obtained using the Mosaic-1
camera on the 4m Mayall Telescope of the Kitt Peak National
Observatory. Two relatively large regions of the sky were observed to
modest depth: the main FLS extragalactic field (17h18m00s,
+59°30'00.0"[J2000]; l=88.3°, b=+34.9°) and the ELAIS-N1
field (16h10m01s, +54°30'36.0"; l=84.2°, b=+44.9°). While
both these fields were in early plans for the FLS, only a single
deep-pointing test observation was made at the ELAIS-N1 location. The
larger Legacy program SWIRE will include this region among its
surveyed areas. The data products of our KPNO imaging (images and
object catalogs) are made available to the community through the World
Wide Web (via the Spitzer Science Center and NOAO Science Archive,
http://ssc.spitzer.caltech.edu/fls/). The overall quality of the
images is high. The measured positions of sources detected in the
images have rms uncertainties in their absolute positions on the order
of 0.35" with possible systematic offsets on the order of 0.1",
depending on the reference frame of comparison. The relative
astrometric accuracy is much better than 1/10 of an arcsecond. Typical
delivered image quality in the images is 1.1" full width at
half-maximum. The images are relatively deep, since they reach a
median 5σ depth limiting magnitude of R=25.5 (Vega) as measured
within a 1.35 FWHM aperture, for which the signal-to-noise ratio (S/N)
is maximal. Catalogs have been extracted with SExtractor, using
thresholds in area and flux for which the number of false detections
is below 1% at R=25. Only sources with S/N>3 have been retained in the
final catalogs. Comparing the galaxy number counts from our images
with those of deeper R-band surveys, we estimate that our observations
are 50% complete at R=24.5. These limits in depth are sufficient to
identify a substantial fraction of the infrared sources that will be
detected by Spitzer.
Use of the data:
Use of these data must be accompanied by citation of the paper and
acknowledgment:
"The National Optical Astronomy Observatory (NOAO) is operated by the
Association of Universities for Research in Astronomy (AURA), Inc.
under cooperative agreement with the National Science Foundation."
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 35 30 Nominal coordinates of the observed subfields
table5.dat 69 32 Properties of images and extracted catalogs
fls/* . 25 *FLS sources
elais/* . 7 *ELAIS field sources
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Note on fls/* and elais/*: The first 10 lines (starting by #) enumerate the
columns
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See also:
http://ssc.spitzer.caltech.edu/fls/ : First Look Survey Home Page
II/255 : SWIRE ELAIS N1 Source Catalogs (Surace+, 2004)
J/A+A/424/371 : 1.4GHz First Look Survey (FLS) (Morganti+, 2004)
J/AJ/125/2411 : SIRTF First-Look Survey (Condon+, 2003)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Field Field ID
9- 10 I2 h RAh Hour of Right Ascension (J2000)
12- 13 I2 min RAm Minute of Right Ascension (J2000)
15- 19 F5.2 s RAs Second of Right Ascension (J2000)
22 A1 --- DE- Sign of the Declination (J2000)
23- 24 I2 deg DEd Degree of Declination (J2000)
26- 27 I2 arcmin DEm Arcmin of Declination (J2000)
29- 32 F4.1 arcsec DEs Arcsec of Declination (J2000)
35 I1 --- Nobs Number of 10 minute observations
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Subfield Subfield ID
12- 13 I2 h RAh Hour of Right Ascension (J2000)
15- 16 I2 min RAm Minute of Right Ascension (J2000)
18- 22 F5.2 s RAs Second of Right Ascension (J2000)
24 A1 --- DE- Sign of the Declination (J2000)
25- 26 I2 deg DEd Degree of Declination (J2000)
28- 29 I2 arcmin DEm Arcminute of Declination (J2000)
31- 35 F5.2 arcsec DEs Arcsecond of Declination (J2000)
38- 41 F4.2 arcsec Seeing Seeing of the combined image
44- 48 F5.2 mag Rlim5 5 σ limiting Cousins R magnitude
51- 55 F5.2 mag Rlim3 3 σ limiting Cousins R magnitude
58- 62 I5 --- Ngal Number of galaxies (1)
65- 69 I5 --- Nstar Number of stars (1)
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Note (1): With S/N≥3 that are not saturated.
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Byte-by-byte Description of file (#): fls/* elais/*
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Bytes Format Units Label Explanations
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1- 6 A6 --- --- [FLSR]
7- 22 A16 --- Source Source designation (based on J2000 position)
24- 25 I2 h RAh Hour of Right Ascension (J2000)
26 A1 --- --- [:]
27- 28 I2 min RAm Minute of Right Ascension (J2000)
29 A1 --- --- [:]
30- 35 F6.3 s RAs Second of Right Ascension (J2000)
37 A1 --- DE- Sign of the Declination (J2000)
38- 39 I2 deg DEd Degree of Declination (J2000)
40 A1 --- --- [:]
41- 42 I2 arcmin DEm Arcminute of Declination (J2000)
43 A1 --- --- [:]
44- 48 F5.2 arcsec DEs Arcsec of Declination (J2000)
50- 54 F5.2 mag RcmagAp ?=99.00 Aperture (3") R magnitude (Cousins)
56- 60 F5.2 mag e_RcmagAp ?=99.00 Error in RcmagAp
62- 66 F5.2 mag RcmagTot Total R magnitude (Cousins)
69- 72 F4.2 mag e_RcmagTot Error in RcmagTot
74- 78 F5.1 --- S/N ?=* Signal-to-noise ratio of the detection
80- 84 F5.3 --- Class Stellarity index computed by SExtractor (1)
86- 90 F5.3 --- Ext The Galactic extinction, taken from
Schlegel et al. (1998ApJ...500..525S 1998ApJ...500..525S)
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Note (1): With 0 for a galaxy, and 1 for a star.
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History:
From electronic version of the journal
(End) Marianne Brouty [CDS] 16-Jun-2005