J/AJ/125/2521 2MASS6x survey of the Lockman Hole (Beichman+, 2003)
A deep 2MASS survey of the Lockman Hole.
Beichman C.A., Cutri R., Jarrett T., Stiening R., Skrutskie M.
<Astron. J. 125, 2521 (2003)>
=2003AJ....125.2521B 2003AJ....125.2521B
ADC_Keywords: Surveys ; QSOs ; Photometry, infrared
Keywords: infrared radiation - quasars: general -
stars: low-mass, brown dwarfs - surveys
Abstract:
We have carried out a survey of the Lockman Hole covering over
24deg2 using the Two Micron All Sky Survey (2MASS) observing system
in a special mode that reaches roughly 1mag deeper than the nominal
2MASS survey. The resultant point-source catalog reaches to
approximately (J, H, Ks)<(17.8, 16.5, 16.0)mag with completeness and
reliability in excess of 90%-95% at the faintest levels. These data
will be useful in identifying sources in SIRTF surveys of this area.
We have cataloged 69,115 objects, almost twice as many as in the
nominal 2MASS survey of this region. The sample includes a large
number of potential new active galaxies, as well as a T dwarf
candidate.
Description:
The Lockman Hole region observed by 2MASS extends from
RA=10 29 45 to 11 00 33 and DE=54° to 60°, J2000.0.
While some 100µm cirrus is visible in the IRAS data, the median
cirrus background in this large area is only 0.4MJy/sr making the
region well suited to deep surveys at SIRTF wavelengths.
The observing strategy for the 6 x data was identical in all respects
to that of the main 2MASS survey, with the exception of the longer
integration time. The 2MASS data were obtained using 37 north-going or
south-going scans obtained over 14 nights between 2000 March 25 and
May 25.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 119 69115 Lockman Hole Point-Source Data
table7.dat 44 2427 Central Positions of Images in Lockman Hole Survey
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 deg RAdeg Right ascension expressed in degrees (J2000)
13- 21 F9.6 deg DEdeg Declination expressed in degrees (J2000)
23- 38 A16 --- 2MASS6xp 2MASS designation (1)
40- 43 F4.2 arcsec errPos Uncertainty in single position axis
46- 51 F6.3 mag Jmag The J-band magnitude
54- 58 F5.3 mag e_Jmag The 1 σ error in Jmag (2)
60- 65 F6.3 mag Hmag The H-band magnitude
68- 72 F5.3 mag e_Hmag The 1 σ error in Hmag (2)
74- 79 F6.3 mag Ksmag The Ks band magnitude
82- 86 F5.3 mag e_Ksmag The 1 σ error in Ksmag (2)
88 I1 --- RJ Read flag for the J-band photometry (3)
89 I1 --- RH Read flag for the H-band photometry (3)
90 I1 --- RKs Read flag for the Ks band photometry (3)
92 I1 --- BJ Blend flag for the J-band photometry (4)
93 I1 --- BH Blend flag for the H-band photometry (4)
94 I1 --- BKs Blend flag for the Ks band photometry (4)
96 A1 --- CJ Confusion flag for the J-band photometry (5)
97 A1 --- CH Confusion flag for the H-band photometry (5)
98 A1 --- CKs Confusion flag for the Ks band photometry (5)
101-105 F5.2 mag Bmag ?=99.99 USNO-A catalog blue magnitude (6)
108-112 F5.2 mag Rmag ?=99.99 USNO-A catalog red magnitude (6)
116-119 F4.2 arcsec Ropt ? Separation between optical source and 2MASS
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Note (1): Sexagesimal position in HHMMSSSS, DDMMSSS format.
For right ascension, the SSSS is quoted in centiseconds of time. For
declination the SSS is quoted in deciseconds of arc.
2MASS6xp JHHMMSSss+DDMMSSs in Simbad
Note (2): 9.999 or 8.888 denotes upper limit.
Note (3): Read flags:
0 = No detection;
1 = Read-1 detection;
2 = Read2-Read-1 detection;
4 = Read2-Read-1 detection on two apparitions.
Note (4): Blend flags:
0 = No detection;
1 = One source;
2 = Attempt to break up source into two sources (assign upper limit).
Note (5): Confusion flags:
0 = No confusion;
B = Blend.
Note (6): 99.99 denotes upper limit.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- FITSfile FITS file name
24- 33 F10.6 deg RAdeg Right ascension of image center expressed in
degrees (J2000)
36- 44 F9.6 deg DEdeg Declination of image center expressed in
degrees (J2000)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 16-Jun-2003