J/AJ/125/1537 QUIRC Chandra sources in OMC 2/3 (Tsujimoto+, 2003)
Deep near-infrared observations and identifications of Chandra sources in
Orion Molecular Clouds 2 and 3.
Tsujimoto M., Koyama K., Kobayashi N., Goto M., Tsuboi Y., Tokunaga A.T.
<Astron. J. 125, 1537 (2003)>
=2003AJ....125.1537T 2003AJ....125.1537T
ADC_Keywords: Stars, pre-main sequence ; Infrared sources ; X-ray sources ;
Photometry, infrared
Keywords: infrared radiation - stars: individual (Orion Molecular Cloud 2/3) -
stars: pre-main-sequence - X-rays
Abstract:
We conducted deep near-infrared (NIR) imaging observations of Orion
molecular clouds 2 and 3 using the Quick Infrared Camera on the
88 inch (2.2m) telescope of the University of Hawaii. Our purposes
were (1) to generate a comprehensive NIR source catalog of these
star-forming clouds and (2) to identify the NIR counterpart of the
Chandra X-ray sources that have no counterpart in the Two Micron All
Sky Survey (2MASS) catalog. Our J-, H-, and K-band observations are
∼2mag deeper than those of 2MASS and match the current Chandra
observation well. We detected 1448 NIR sources, for which we derived
the position, the J-, H-, and K-band magnitude, and the 2MASS
counterpart. Using this catalog, we identified the NIR counterpart for
∼42% of the 2MASS unidentified Chandra sources. The nature of these
Chandra sources are discussed using their NIR colors and spatial
distributions, and a dozen protostar and brown dwarf candidates are
identified.
Description:
We conducted the mosaic mapping, to sweep the whole Chandra field,
once in the H (06 Feb) and K band (04 Feb), and twice for the J band
(05 Feb, 11-13 March), spending six half-nights of 2001 February 4-6
and 2001 March 11-13. All nights were photometric, and the seeing was
0.7"-1.1".
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 79 1448 QUIRC source list
table3.dat 59 74 QUIRC identified Chandra sources
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See also:
B/chandra : The Chandra Archive Log (CXC, 2002)
B/2mass : The 2MASS database (IPAC/UMass, 2000)
II/241 : 2MASS Catalog Intermediate Data Release (IPAC/UMass, 2000)
J/AJ/120/1426 : Chandra sources in ONC + BN-KL (Garmire+, 2000)
J/ApJ/549/441 : Chandra observations of Orion Trapezium (Schulz+, 2001)
J/ApJ/582/382 : Chandra X-ray sources in Orion Nebula Cluster (Flaccomio+ 2003)
J/ApJ/566/974 : Chandra obs. of YSOs in OMC-2 and OMC-3 (Tsujimoto+, 2002)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- TKK Object identification number (TKK NNNN)
6- 7 I2 h RAh Hour of right ascension (J2000)
9- 10 I2 min RAm Minute of right ascension (J2000)
12- 16 F5.2 s RAs Second of right ascension (J2000) (1)
18 A1 --- DE- Sign of the declination (J2000)
19- 20 I2 deg DEd Degree of declination (J2000)
22- 23 I2 arcmin DEm Arcminute of declination (J2000)
25- 28 F4.1 arcsec DEs Arcsecond of declination (J2000) (1)
30 A1 --- l_Jmag Limit flag on Jmag (2)
31- 35 F5.2 mag Jmag The 2MASS J-band magnitude
37 A1 --- f_Jmag [d] Flag on Jmag (3)
39 A1 --- l_Hmag Limit flag on Hmag (2)
40- 44 F5.2 mag Hmag The 2MASS H-band magnitude
46 A1 --- f_Hmag [d] Flag on Hmag (3)
48 A1 --- l_Kmag Limit flag on Kmag (2)
49- 53 F5.2 mag Kmag The 2MASS K-band magnitude
55 A1 --- f_Kmag [d] Flag on Kmag (3)
57- 78 A22 --- 2MASS The 2MASS identification
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Note (1): Truncated value.
Note (2): Note on limit flags:
> = The upper limit of the flux (the lower limit of the magnitude)
for source with less than 3 σ detection;
< = Saturated QUIRC magnitude (brighter than 11mag) without a 2MASS
counterpart, recognizing the value as the lower limit of the
flux (the upper limit of the magnitude).
Note (3): Notes:
d = Saturated QUIRC magnitude (brighter than 11mag). Replaced with
its 2MASS magnitude.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- [TKT2002] X-ray source identification (1)
6- 7 A2 --- f_[TKT2002] Flag on [TKT2002] (2)
9- 11 A3 --- --- [TKK]
13- 29 A17 --- QUIRC The QUIRC source identification,
JHHMMSSss+DDMMSSs
31- 34 F4.1 arcsec Sep Separation between Chandra and QUIRC sources
36- 39 F4.1 arcmin Angle The off-axis angle of the Chandra source
41 A1 --- l_Jmag Limit flag on Jmag
42- 46 F5.2 mag Jmag The J-band magnitude in California
Institute of Technology (CIT) system
48 A1 --- l_J-H Limit flag on J-H
49- 52 F4.2 mag J-H The (J-H) color in CIT system
54 A1 --- l_H-K Limit flag on H-K
55- 58 F4.2 mag H-K ? The (H-K) color in CIT system
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Note (1): The nomenclature of X-ray sources follows Tsujimoto et al. 2002.
Note (2): Notes:
a = Protostar candidate (see section 5.2.1)
b = Brown dwarf candidate (see section 5.2.1)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 29-Apr-2003