II/317 The CFHTLS Survey (T0007 release) (Hudelot+ 2012)
The final Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) release.
Hudelot P., Cuillandre J.-Ch., Withington K., Goranova Y., McCracken H.,
Magnard F., Mellier Y., Regnault N., Betoule M., Aussel H., Kavelaars J.J.,
Fernique P., Bonnarel F., Ochsenbein F., Ilbert O.
=2012yCat.2317....0H 2012yCat.2317....0H
ADC_Keywords: Surveys ; Photometry, SDSS
Description:
Canada and France joined a large fraction (∼50%) of their dark and
grey telescope time from mid-2003 to early 2009 for a large project,
the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The data
acquisition and calibration has been a major undertaking for the
Canadian and French communities: more than 2300 hours over 5 years
(an equivalent of 450 nights) have been devoted to the survey using
the wide field optical imaging camera MegaCam, a 1°x1° field
of view 340 Megapixel camera.
The CFHTLS comprises 2 components: "CFHTLS Deep", 4 independent
1deg2 MegaCam pointing, and "CFHT Wide" comprising 171 MegaCam
pointings covering ∼155deg2 in 4 contiguous independent patches.
All areas are located far from the galactic plane, and their central
positions are:
--------------------------------------------------
Field RA (J2000) Dec Galactic position
--------------------------------------------------
W1 02:18 -07:00 172.468 -61.242
W2 08:54 -04:15 232.067 +24.743
W3 14:17:54 +54:30:31 098.850 +58.390
W4 22:13:18 +01:19 063.243 -42.511
D1 02:25:59 -04:29:40 171.993 -58.054
D2 10:00:28 +02:23:30 236.616 +42.227
D3 14:19:27 +52:40:56 096.227 +59.642
D4 22:15:31 -17:43:56 039.271 -52.925
--------------------------------------------------
This final release of the CFHTLS benefits greatly from vastly improved
flat-fielding and photometric calibration techniques developed by the
Supernovae Legacy Survey (SNLS) team and CFHT which allows us to
significantly improve the precision of our photometric calibration
compared to previous releases.
The astrometric accuracy reaches 0.02arcsec internal and 0.2arcsec
external.
The set of filters used for the survey are close to the SDSS filter
set; their characteristics and a comparison to SDSS can be found at
http://www3.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/megapipe/docs/filters.html
Please ee the documentation file "T0007-doc.pdf" for details
concerning this T0007 release.
Acknowledging CFHTLS in publications:
Please note the acknowledgment text for publications when using
the CFHT-LS (archived or proprietary) data:
http://www.cfht.hawaii.edu/Science/CFHLS/cfhtlspublitext.html
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cfhtls_w.sam 481 1000 Sample of the CFHTLS Wide Survey
(out of 35,651,677 sources)
cfhtls_d.sam 557 1000 Sample of the CFHTLS Deep Survey
(out of 2,293,851 sources)
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Byte-by-byte Description of file: cfhtls_w.sam
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Bytes Format Units Label Explanations
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1- 11 A11 --- CFHTLS Unique object identifier (CFHTLS_INDEX) (G1)
13- 22 F10.6 deg RAdeg Right ascension (J2000) (ALPHA_J2000)
24- 33 F10.6 deg DEdeg Declination (J2000) (DELTA_J2000)
35- 40 F6.3 mag umag ? u*-band 3"-aperture AB mag. (MAGAPERu)
42- 47 F6.3 mag gmag ? g-band 3"-aperture AB mag. (MAGAPERg)
49- 54 F6.3 mag rmag ? r-band 3"-aperture AB mag. (MAGAPERr)
56- 61 F6.3 mag imag ? i/y-band 3"-aperture AB mag. (MAGAPERi) (2)
63- 68 F6.3 mag zmag ? z-band 3"-aperture AB mag. (MAGAPERz)
70- 75 F6.3 mag e_umag ? RMS error in umag (MAGERRAPERu)
77- 82 F6.3 mag e_gmag ? RMS error in gmag (MAGERRAPERg)
84- 89 F6.3 mag e_rmag ? RMS error in rmag (MAGERRAPERr)
91- 96 F6.3 mag e_imag ? RMS error in imag (MAGERRAPERi)
98-103 F6.3 mag e_zmag ? RMS error in zmag (MAGERRAPERz)
105-112 I8 --- Seq Running object number (NUMBER)
114-121 F8.2 pix Xpos Object position along x (X_IMAGE)
123-130 F8.2 pix Ypos Object position along y (Y_IMAGE)
132-138 F7.2 arcsec a Profile RMS along major axis (A_WORLD)
140-145 F6.2 arcsec b ? Profile RMS along minor axis (B_WORLD)
147-149 I3 deg pa [-90/90]? Position angle (THETA_WORLD)
151-153 I3 --- Sfl [0/63] Sextractor extraction flags (FLAGS) (G3)
155-157 I3 --- Tfl [0/255] TERAPIX flag mask (FLAG_MASK) (G4)
159 I1 --- ifl [0/1] i-filter used, 1=y (FLAG_IFILTER) (2)
161-166 F6.3 mag E(B-V) E(B-V) extinction from Schlegel maps (E(B-V))
--------------------------------------------------------------------------------
168-173 F6.3 mag umagA ? u*-band Kron-like aperture mag. (MAGAUTOu)
175-180 F6.3 mag e_umagA ? RMS error for umagA (MAGERRAUTOu)
182-187 F6.3 mag umag20 ? u*-band 20*FWHM magnitude (MAGIQ20u)
189-194 F6.3 mag e_umag20 ? Mean error on umag20 (MAGERRIQ20u)
196-207 F12.2 pix urad ? u*-band half-light radius (FLUXRADIUSu))
209-212 F4.2 --- ucl Star/galaxy class in u*-band (CLASSSTARu)
214-222 F9.3 ct uFpk ? u-band peak flux above background (FLUXMAXu)
224-229 F6.3 mag/arcsec2 umu ? u*-band peak surface brightness (MUMAXu)
--------------------------------------------------------------------------------
231-236 F6.3 mag gmagA ? g-band Kron-like aperture mag. (MAGAUTOg)
238-243 F6.3 mag e_gmagA ? RMS error for gmagA (MAGERRAUTOg)
245-250 F6.3 mag gmag20 ? g-band 20*FWHM magnitude (MAGIQ20g)
252-257 F6.3 mag e_gmag20 ? Mean error on gmag20 (MAGERRIQ20g)
259-270 F12.2 pix grad ? g-band half-light radius (FLUXRADIUSg)
272-275 F4.2 --- gcl Star/galaxy class in g-band (CLASSSTARg)
277-285 F9.3 ct gFpk ? g-band peak flux above background (FLUXMAXg)
287-292 F6.3 mag/arcsec2 gmu ? g-band peak surface brightness (MUMAXg)
--------------------------------------------------------------------------------
294-299 F6.3 mag rmagA ? r-band Kron-like aperture mag. (MAGAUTOr)
301-306 F6.3 mag e_rmagA ? RMS error for rmagA (MAGERRAUTOr)
308-313 F6.3 mag rmag20 ? r-band 20*FWHM magnitude (MAGIQ20r)
315-320 F6.3 mag e_rmag20 ? Mean error on rmag20 (MAGERRIQ20r)
322-333 F12.2 pix rrad ? r-band half-light radius (FLUXRADIUSr)
335-338 F4.2 --- rcl Star/galaxy class in r-band (CLASSSTARr)
340-348 F9.3 ct rFpk ? r-band peak flux above background (FLUXMAXr)
350-355 F6.3 mag/arcsec2 rmu ? r-band peak surface brightness (MUMAXr)
--------------------------------------------------------------------------------
357-362 F6.3 mag imagA ? i-band Kron-like aperture mag.(MAGAUTOi) (2)
364-369 F6.3 mag e_imagA ? RMS error for imagA (MAGERRAUTOi)
371-376 F6.3 mag imag20 ? i-band 20*FWHM magnitude (MAGIQ20i) (2)
378-383 F6.3 mag e_imag20 ? Mean error on imag20 (MAGERRIQ20i)
385-396 F12.2 pix irad ? i-band half-light radius (FLUXRADIUSi) (2)
398-401 F4.2 --- icl Star/galaxy class in i-band (CLASSSTARi) (2)
403-411 F9.3 ct iFpk ? i-band peak flux above background (FLUXMAXi)
413-418 F6.3 mag/arcsec2 imu ? i-band peak surface brightness (MUMAXi) (2)
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420-425 F6.3 mag zmagA ? z-band Kron-like aperture mag. (MAGAUTOz)
427-432 F6.3 mag e_zmagA ? RMS error for zmagA (MAGERRAUTOz)
434-439 F6.3 mag zmag20 ? z-band 20*FWHM magnitude (MAGIQ20z)
441-446 F6.3 mag e_zmag20 ? Mean error on zmag20 (MAGERRIQ20z)
448-459 F12.2 pix zrad ? z-band half-light radius (FLUXRADIUSz)
461-464 F4.2 --- zcl Star/galaxy class in z-band (CLASSSTARz)
466-474 F9.3 ct zFpk ? z-band peak flux above background (FLUXMAXz)
476-481 F6.3 mag/arcsec2 zmu ? z-band peak surface brightness (MUMAXz)
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Note (2): Magnitude in i- or y-band filter, depending on the "ifl" flag:
0 = the object was observed in filter i.MP9701,
1 = the object was observed in filter i.MP9702 (y filter)
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Byte-by-byte Description of file: cfhtls_d.sam
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Bytes Format Units Label Explanations
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1- 12 A12 --- CFHTLS Unique object identifier (CFHTLS_INDEX) (G1)
14- 23 F10.6 deg RAdeg Right ascension (J2000) (ALPHA_J2000)
25- 34 F10.6 deg DEdeg Declination (J2000) (DELTA_J2000)
36- 41 F6.3 mag umag ? u*-band 3"-aperture AB mag. (MAGAPERu)
43- 48 F6.3 mag gmag ? g-band 3"-aperture AB mag. (MAGAPERg)
50- 55 F6.3 mag rmag ? r-band 3"-aperture AB mag. (MAGAPERr)
57- 62 F6.3 mag imag ? i-band 3"-aperture AB mag. (MAGAPERi)
64- 69 F6.3 mag ymag ? y-band 3"-aperture AB mag. (MAGAPERy)
71- 76 F6.3 mag zmag ? z-band 3"-aperture AB mag. (MAGAPERz)
78- 83 F6.3 mag e_umag ? RMS error in umag (MAGERRAPERu)
85- 90 F6.3 mag e_gmag ? RMS error in gmag (MAGERRAPERg)
92- 97 F6.3 mag e_rmag ? RMS error in rmag (MAGERRAPERr)
99-104 F6.3 mag e_imag ? RMS error in imag (MAGERRAPERi)
106-111 F6.3 mag e_ymag ? RMS error in zmag (MAGERRAPERy)
113-118 F6.3 mag e_zmag ? RMS error in zmag (MAGERRAPERz)
120-127 I8 --- Seq Running object number (NUMBER)
129-136 F8.2 pix Xpos Object position along x (X_IMAGE)
138-145 F8.2 pix Ypos Object position along y (Y_IMAGE)
147-153 F7.2 arcsec a Profile RMS along major axis (A_WORLD)
155-160 F6.2 arcsec b ? Profile RMS along minor axis (B_WORLD)
162-164 I3 deg pa [-90/90]? Position angle (THETA_WORLD)
166-168 I3 --- Sfl [0/63] Sextractor extraction flags (FLAGS) (G3)
170-172 I3 --- Tfl [0/255] TERAPIX flag mask (FLAG_MASK) (G4)
174-179 F6.3 mag E(B-V) E(B-V) extinction from Schlegel maps (E(B-V))
--------------------------------------------------------------------------------
181-186 F6.3 mag umagA ? u*-band Kron-like aperture mag. (MAGAUTOu)
188-193 F6.3 mag e_umagA ? RMS error for umagA (MAGERRAUTOu)
195-200 F6.3 mag umag20 ? u*-band 20*FWHM magnitude (MAGIQ20u)
202-207 F6.3 mag e_umag20 ? Mean error on umag20 (MAGERRIQ20u)
209-220 F12.2 pix urad ? u*-band half-light radius (FLUXRADIUSu))
222-225 F4.2 --- ucl Star/galaxy class in u*-band (CLASSSTARu)
227-235 F9.3 ct uFpk ? u-band peak flux above background (FLUXMAXu)
237-242 F6.3 mag/arcsec2 umu ? u*-band peak surface brightness (MUMAXu)
--------------------------------------------------------------------------------
244-249 F6.3 mag gmagA ? g-band Kron-like aperture mag. (MAGAUTOg)
251-256 F6.3 mag e_gmagA ? RMS error for gmagA (MAGERRAUTOg)
258-263 F6.3 mag gmag20 ? g-band 20*FWHM magnitude (MAGIQ20g)
265-270 F6.3 mag e_gmag20 ? Mean error on gmag20 (MAGERRIQ20g)
272-283 F12.2 pix grad ? g-band half-light radius (FLUXRADIUSg)
285-288 F4.2 --- gcl Star/galaxy class in g-band (CLASSSTARg)
290-298 F9.3 ct gFpk ? g-band peak flux above background (FLUXMAXg)
300-305 F6.3 mag/arcsec2 gmu ? g-band peak surface brightness (MUMAXg)
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307-312 F6.3 mag rmagA ? r-band Kron-like aperture mag. (MAGAUTOr)
314-319 F6.3 mag e_rmagA ? RMS error for rmagA (MAGERRAUTOr)
321-326 F6.3 mag rmag20 ? r-band 20*FWHM magnitude (MAGIQ20r)
328-333 F6.3 mag e_rmag20 ? Mean error on rmag20 (MAGERRIQ20r)
335-346 F12.2 pix rrad ? r-band half-light radius (FLUXRADIUSr)
348-351 F4.2 --- rcl Star/galaxy class in r-band (CLASSSTARr)
353-361 F9.3 ct rFpk ? r-band peak flux above background (FLUXMAXr)
363-368 F6.3 mag/arcsec2 rmu ? r-band peak surface brightness (MUMAXr)
--------------------------------------------------------------------------------
370-375 F6.3 mag imagA ? i-band Kron-like aperture mag.(MAGAUTOi)
377-382 F6.3 mag e_imagA ? RMS error for imagA (MAGERRAUTOi)
384-389 F6.3 mag imag20 ? i-band 20*FWHM magnitude (MAGIQ20i)
391-396 F6.3 mag e_imag20 ? Mean error on imag20 (MAGERRIQ20i)
398-409 F12.2 pix irad ? i-band half-light radius (FLUXRADIUSi)
411-414 F4.2 --- icl Star/galaxy class in i-band (CLASSSTARi)
416-424 F9.3 ct iFpk ? i-band peak flux above background (FLUXMAXi)
426-431 F6.3 mag/arcsec2 imu ? i-band peak surface brightness (MUMAXi)
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433-438 F6.3 mag ymagA ? y-band Kron-like aperture mag. (MAGAUTOy)
440-445 F6.3 mag e_ymagA ? RMS error for ymagA (MAGERRAUTOy)
447-452 F6.3 mag ymag20 ? y-band 20*FWHM magnitude (MAGIQ20y)
454-459 F6.3 mag e_ymag20 ? Mean error on ymag20 (MAGERRIQ20y)
461-472 F12.2 pix yrad ? y-band half-light radius (FLUXRADIUSy)
474-477 F4.2 --- ycl Star/galaxy class in y-band (CLASSSTARy)
479-487 F9.3 ct yFpk ? y-band peak flux above background (FLUXMAXy)
489-494 F6.3 mag/arcsec2 ymu ? y-band peak surface brightness (MUMAXy)
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496-501 F6.3 mag zmagA ? z-band Kron-like aperture mag. (MAGAUTOz)
503-508 F6.3 mag e_zmagA ? RMS error for zmagA (MAGERRAUTOz)
510-515 F6.3 mag zmag20 ? z-band 20*FWHM magnitude (MAGIQ20z)
517-522 F6.3 mag e_zmag20 ? Mean error on zmag20 (MAGERRIQ20z)
524-535 F12.2 pix zrad ? z-band half-light radius (FLUXRADIUSz)
537-540 F4.2 --- zcl Star/galaxy class in z-band (CLASSSTARz)
542-550 F9.3 ct zFpk ? z-band peak flux above background (FLUXMAXz)
552-557 F6.3 mag/arcsec2 zmu ? z-band peak surface brightness (MUMAXz)
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Global Notes:
Note (G1): The unique object identifier in the CFHTLS Wide survey is
written "sptt_nnnnnn" with the meaning:
s (digit 1) = survey with Deep = 0 / Wide = 1
p (digit 2) = patch index (1 for W1, etc)
tt (digits 3/4) = tile index
nnnnnn (digits 6-11) = object index in the survey/index/tile
Note (G3): The Sextractor binary flags are:
1 = object has neighbors or bad pixels that bias the photometry
2 = object originally blended with another one
4 = at least one pixel of the object is saturated
8 = object truncated (too close to an image boundary)
16 = aperture data are incomplete or corrupted
32 = isophotal data are incomplete or corrupted
Note (G4): The TERAPIX binary flags are:
1 = star
2 = saturated star in one of the filters
4 = masked region in z-band
8 = masked region in y-band
16 = masked region in i-band
32 = masked region in r-band
64 = masked region in g-band
128 = masked region in u*-band
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(End) Francois Ochsenbein [CDS], Patrick Hudelot [IAP] 28-Sep-2012