II/310 UKIDSS-DR7 Large Area Survey (Lawrence+ 2011)
UKIRT Infrared Deep Sky Survey (UKIDSS) Release 7
UKIDSS Consortium
<Mon. Not. R. Astron. Soc. 379, 1599 (2007) >
=2012yCat.2310....0U 2012yCat.2310....0U
ADC_Keywords: Surveys ; Infrared sources ; Photometry, infrared
Keywords: surveys - infrared: general
Description:
The UKIRT Infrared Deep Sky Survey (UKIDSS) is a large-scale near-IR
survey which aim is to cover 7500 square degrees of the Northern sky.
The survey is carried out using the Wide Field Camera (WFCAM), with a
field of view of 0.21 square degrees, mounted on the 3.8m United
Kingdom Infra-red Telescope (UKIRT) in Hawaii.
The Large Area Survey (LAS) covers an area of 4000 square degrees in
high Galactic latitudes (extragalactic) in the four bands Y(1.0um)
J(1.2um) H(1.6um) and K(2.2um) to a depth of K = 18.4.
Details of the survey can be found in the in the paper by Lawrence
et al. (2007MNRAS.379.1599L 2007MNRAS.379.1599L)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
las.sam 440 1000 Sample of the UKIDSS-DR7 Large Area Survey
(among 58060655 sources)
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See also:
http://www.ukidss.org/surveys/surveys.html : UKIDSS Surveys
http://surveys.roe.ac.uk/wsa/dr7plus_release.html : UKIDSS-DR7 Release
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: las.sam
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right ascension (J2000)
11- 19 F9.5 deg DEdeg Declination (J2000)
22- 27 F6.3 mag Ymag ? UKIDSS Y default magnitude (yAperMag3) (1)
29- 34 F6.3 mag Jmag ? UKIDSS J default magnitude (j_1AperMag3) (1)
36- 41 F6.3 mag Hmag ? UKIDSS H default magnitude ( hAperMag3) (1)
43- 48 F6.3 mag Kmag ? UKIDSS K default magnitude (kAperMag3) (1)
51- 56 F6.3 mag e_Ymag ? Mean error on Ymag (yAperMag3Err)
58- 63 F6.3 mag e_Jmag ? Mean error on Jmag (j_1AperMag3Err)
65- 70 F6.3 mag e_Hmag ? Mean error on Hmag (hAperMag3Err)
72- 77 F6.3 mag e_Kmag ? Mean error on Kmag (kAperMag3Err)
79- 90 I12 --- ID Unique ID of this merged detection (sourceID)
92-100 F9.4 yr Epoch Epoch of position measurement (epoch)
102-103 I2 --- nf Number of frames (nFrames)
105-116 I12 --- IDprior ?=0 ID for overlapping source (priOrSec )
119-124 F6.2 --- mStat Merged profile class statistic (mergedClassStat)
126-127 I2 --- cl [-3,1] Merged source class (mergedClass) (2)
129-132 F4.2 --- pS [0,1] Probability of being a star (pStar)
134-137 F4.2 --- pG [0,1] Probability of being a galaxy (pGalaxy)
139-142 F4.2 --- pN [0,1] Probability of being noise (pNoise)
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145-150 F6.3 mag Ytot ? Total point source Y magnitude (yHallMag)
152-157 F6.3 mag e_Ytot ? Mean error on Ytot (yHallMagErr)
159-164 F6.3 mag pYmag ? Petrosian Y magnitude (yPetroMag)
166-171 F6.3 mag e_pYmag ? Mean error on pYmag (yPetroMagErr)
173-180 F8.3 pix Ydiam ? Y-band RMS of axes of ellipse fit (yGausig)
182-185 F4.2 --- Yell [0,1]? Source ellipticity in Y-band (yEll)
187-191 F5.1 deg Ypa [0,180]? Position angle of Y-band ellipse (yPA)
193-195 I3 --- Ybad Y-band zero confidence pixels (yErrBits) (3)
197-198 I2 --- Ycl [-3,1]? Y-band source class (yClass) (2)
200-206 I7 --- Yflags [0,8388607]? Y-band flags (yppErrBits) (4)
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209-214 F6.3 mag Jtot ? Total point source J magnitude (j_1HallMag)
216-221 F6.3 mag e_Jtot ? Mean error on Jtot (j_1HallMagErr)
223-228 F6.3 mag pJmag ? Petrosian J magnitude (j_1PetroMag)
230-235 F6.3 mag e_pJmag ? Mean error on pJmag (j_1PetroMagErr)
237-244 F8.3 pix Jdiam ? J-band RMS of axes of ellipse fit (j_1Gausig)
246-249 F4.2 --- Jell [0/1]? J-band ellipticity (1-b/a) (j_1Ell)
251-255 F5.1 deg Jpa [0,180]? J-band position angle (j_1PA)
257-259 I3 --- Jbad J-band zero confidence pixels (j_1ErrBits) (3)
261-262 I2 --- Jcl [-3,1]? J-band source class (j_1Class) (2)
264-270 I7 --- Jflags [0,8388607] J-band flags (j_1ppErrBits) (4)
272-277 F6.3 arcsec Jdx ? ξ offset to Y-band source (j_1Xi)
279-284 F6.3 arcsec Jdy ? η offset to Y-band source (j_1Eta)
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287-292 F6.3 mag Htot ? Total point source H magnitude (hHallMag)
294-299 F6.3 mag e_Htot ? Mean error on Htot (hHallMagErr)
301-306 F6.3 mag pHmag ? Petrosian H magnitude (hPetroMag)
308-313 F6.3 mag e_pHmag ? Mean error on Hpag (hPetroMagErr)
315-322 F8.3 pix Hdiam ? RMS of axes of ellipse fit in H-band (hGausig)
324-327 F4.2 --- Hell ? Ellipticity in H-band (hEll)
329-333 F5.1 deg Hpa [0,180]? H-band position angle (hPA)
335-337 I3 --- Hbad H-band zero confidence pixels (hErrBits) (3)
339-340 I2 --- Hcl [-3,1] H-band source class (hClass) (2)
342-348 I7 --- Hflags [0,8388607] flags (hppErrBits) (4)
350-355 F6.3 arcsec Hdx ? ξ offset to Y-band source (hXi)
357-362 F6.3 arcsec Hdy ? η offset to Y-band source (hEta)
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365-370 F6.3 mag Ktot ? Total point source K magnitude (kHallMag)
372-377 F6.3 mag e_Ktot ? Mean error on Ktot (kHallMagErr)
379-384 F6.3 mag pKmag ? Petrosian K magnitude (kPetroMag)
386-391 F6.3 mag e_pKmag ? Mean error on pKmag (kPetroMagErr)
393-400 F8.3 pix Kdiam ? RMS of axes of ellipse fit in K-band (kGausig)
402-405 F4.2 --- Kell ? K-band ellipticity (kEll)
407-411 F5.1 deg Kpa [0,180]? K-band position angle (kPA)
413-415 I3 --- Kbad K-band zero confidence pixels (kErrBits) (3)
417-418 I2 --- Kcl [-3,1] K-band source class (kClass) (2)
420-426 I7 --- Kflags [0,8388607] flags (kppErrBits) (4)
428-433 F6.3 arcsec Kdx ? ξ offset to Y-band source (kXi)
435-440 F6.3 arcsec Kdy ? η offset to Y-band source (kEta)
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Note (1): recommended magnitude, corrected from a 2.0arcsec aperture
diameter), valid for both point and extended sources.
The filters characteristics are (from Hewett et al. 2006MNRAS.367..454H 2006MNRAS.367..454H)
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Y 1.031 ± 0.102 µm
J 1.248 ± 0.159 µm
H 1.631 ± 0.292 µm
K 2.201 ± 0.351 µm
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Note (2): The profile classification takes the following values:
-3 = Probable galaxy (with a probability between 70 and 90%)
-2 = Probable star (with a probability between 70 and 90%)
-1 = Star (with a probability ≥ 90%)
0 = Noise (with a probability ≥ 90%)
+1 = Galaxy (with a probability ≥ 90%)
Note (3): count of the number of zero confidence pixels in the default
(2arcsec diameter) aperture.
Note (4): the post-processing error bits are resumed in a number defined
as {Sum}2b, b being the bit number between 0 and 31.
The meaning of b's is as follows:
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b decimal hexadecimal Meaning
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4 16 0x00000010 Deblended
6 64 0x00000040 Bad pixel(s) in default aperture
15 32768 0x00008000 Source in poor flat field region
16 65536 0x00010000 Close to saturated
17 131072 0x00020000 Photometric calibration probably subject
to systematic error
19 524288 0x00080000 Possible crosstalk artefact/contamination
22 4194304 0x00400000 Lies within a dither offset of the stacked
frame boundary
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Nomenclature Notes:
The correct designation for UKIDSS-LAS sources is:
ULAS JHHMMSS.ss+DDMMSS.s
following the LAS position, truncated to 0.01s in right ascension
and 0.1arcsec in declination.
Acknowledgements:
It is a pleasure to thank Nigel Hambly, who helped in the preparation
of this catalogue.
(End) Francois Ochsenbein [CDS] 29-Mar-2012