J/A+A/564/A29 Optical and near-infrared photometry in Orion A (Bouy+, 2014)
Orion Revisited: II. The foreground population to Orion A.
Bouy H., Alves J., Bertin E., Sarro L.M., Barrado D.
<Astron. Astrophys. 564, A29 (2014)>
=2014A&A...564A..29B 2014A&A...564A..29B
ADC_Keywords: Molecular clouds ; Stars, pre-main sequence ; Photometry, SDSS ;
Photometry, infrared ; Photometry, CCD
Keywords: stars: formation - stars: massive - stars: pre-main sequence -
ISM: clouds - ISM: individual objects: Orion A
Abstract:
Following the recent discovery a large population of young stars in
front of the Orion Nebula we carried out an observational campaign
with the DECam wide-field camera covering approximately 10 square
degrees centered on NGC 1980 to confirm, probe the extent, and
characterize this foreground population of pre-main sequence stars. We
used multi-wavelength wide field images and catalogs to identify
potential foreground pre-main sequence stars using a novel
probabilistic technique based on a careful selection of colors and
luminosities.
We confirmed the presence of a large foreground population towards the
Orion A cloud. This population contains several distinct sub-groups
including NGC 1980 and NGC 1981 and stretches over several degrees in
front of the Orion A cloud. By comparing the location of their
sequence in various color-magnitude diagrams to other clusters, we
found a distance and an age of 380pc and 5 to 10Myr, in good
agreement with previous estimates. Our final sample includes 2123
candidate members and is complete from below the hydrogen burning
limit to about 0.3M☉ where the data starts to be limited by
saturation. Extrapolating the mass function to the high masses, we
estimated a total number of ∼2600 members in the surveyed region.
Description:
Photometric measurements in the Sloan g,r,i,z bands, UKIRT Y-band and
2MASS J,H,K bands.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 135 605020 Positions and griz Y JHKs magnitudes
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See also:
VIII/12 : Orion A Emission-Line Surveys (Jewell+ 1989)
J/AJ/109/709 : K survey of Ori A molecular cloud (Ali+ 1995)
J/A+A/327/1177 : Kinematics and electron temperatures in Orion A (Wilson+ 1997)
J/A+A/392/239 : IR survey of outflows in Orion A (Stanke+, 2002)
J/ApJ/653/383 : SCUBA observations in Orion A South region (Johnstone+, 2006)
J/ApJ/665/1194 : Dense cores in the Orion A cloud survey (Ikeda+, 2007)
J/A+A/496/153 : Molecular hydrogen flows along Ori A cloud (Davis+, 2009)
J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- Source [1/605020] Unique source number
8- 23 F16.13 deg RAdeg Right ascension (J2000.0)
25- 41 F17.14 deg DEdeg Right ascension (J2000.0)
43- 47 F5.2 mag gmag ? Sloan SDSS g-band magnitude
49- 52 F4.2 mag e_gmag ? Sloan SDSS g-band magnitude error
54- 58 F5.2 mag rmag ? Sloan SDSS r-band magnitude
60- 63 F4.2 mag e_rmag ? Sloan SDSS r-band magnitude error
65- 69 F5.2 mag imag ? Sloan SDSS i-band magnitude
71- 74 F4.2 mag e_imag ? Sloan SDSS i-band magnitude error
76- 80 F5.2 mag zmag ? Sloan SDSS z-band magnitude
82- 85 F4.2 mag e_zmag ? Sloan SDSS z-band magnitude error
87- 91 F5.2 mag Ymag ? UKIRT Y-band magnitude
93- 96 F4.2 mag e_Ymag ? UKIRT Y-band magnitude error
98-102 F5.2 mag Jmag ? 2MASS J-band magnitude
104-107 F4.2 mag e_Jmag ? 2MASS J-band magnitude error
109-113 F5.2 mag Hmag ? 2MASS H-band magnitude
115-118 F4.2 mag e_Hmag ? 2MASS H-band magnitude error
120-124 F5.2 mag Kmag ? 2MASS Ks-band magnitude
126-129 F4.2 mag e_Kmag ? 2MASS K-band magnitude error
131-135 F5.1 % PMemb [0/100]? Membership probability
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Acknowledgements:
Herve Bouy, hbouy(at)cab.inta-csic.es
(End) Herve Bouy [CAB-CSIC, Spain], Patricia Vannier [CDS] 10-Feb-2014