J/ApJS/160/353 Membership of the Orion nebula population (Getman+, 2005)
Membership of the Orion nebula population from the Chandra Orion Ultradeep
Project.
Getman K.V., Feigelson E.D., Grosso N., McCaughrean M.J., Micela G.,
Broos P., Garmire G., Townsley L.
<Astrophys. J. Suppl. Ser., 160, 353-378 (2005)>
=2005ApJS..160..353G 2005ApJS..160..353G (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; X-ray sources ;
Infrared sources
Keywords: binaries: general - stars: pre-main-sequence - X-rays: stars
open clusters and associations: individual (Orion Nebula Cluster)
Abstract:
The Chandra Orion Ultradeep project (COUP) observation described in a
companion paper by Getman et al. (2005, Cat. J/ApJS/160/319)
provides an exceptionally deep X-ray survey of the Orion Nebula
Cluster and associated embedded young stellar objects. Membership of
the region is important for studies of the stellar IMF, cluster
dynamics, and star formation. The COUP study detected 1616 X-ray
sources. In this study we confirm cloud membership for 1315 stars,
identify 16 probable foreground field stars having optical
counterparts with discrepant proper motions, and classify the
remaining 285 X-ray sources, of which 51 are lightly and 234 heavily
obscured.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 78 42 Flaring COUP X-ray sources without optical or
near-infrared counterparts
table2.dat 90 243 Non-flaring COUP X-ray sources without optical
or near-infrared counterparts
table3.dat 67 61 COUP double sources with <3" separations
table4.dat 111 33 COUP stars with discrepant proper motions
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/ApJS/160/319 : COUP: observations and source lists (Getman+, 2005)
J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)
J/AJ/116/1816 : JHKLMNOPQ photometry in Orion cluster (Hillenbrand+, 1998)
J/ApJ/540/236 : KH photometry of Orion Nebula Cluster (Hillenbrand+, 2000)
J/A+A/396/513 : Stellar Rotation in the Orion Nebula Cluster (Herbst+, 2002)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- COUP COUP Sequence number (1)
6- 26 A21 --- Name COUP IAU identification (COUP JHHMMSS.s+DDMMSS)
28- 34 F7.1 ct NCt Total (0.5-8keV) net counts in extracted area
36- 42 F7.1 ct NCh Hard (2-8keV) net counts in extracted area
44- 47 F4.2 --- PSF Fraction of PSF in the extracted area
49- 51 F3.1 keV MedE Median energy of extracted photons in the
(0.5-8keV) band corrected for background
53- 56 F4.1 [cm-2] NH ? Log of the source hydrogen column density (2)
58- 61 F4.1 keV kT ? Source plasma energy from the spectral fit
63- 69 F7.3 aW/m2 Fh ? Observed hard band flux in
units of 10-15erg/s/cm2
71- 74 F4.1 [cm-2] Log of the average OMC hydrogen column
density (3)
76- 85 A10 --- Memb Membership class derived here (G1)
87- 90 F4.2 --- Prob ? Membership probability (only in table 2)
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Note (1): Spectral results are unreliable for COUP 84, 257, 495, and 1033
because the fitting procedure failed due to substantial hard-band
contamination. Spectral results are unreliable for COUP 479, 505,
and 1157 because the fitting procedure failed due to substantial
soft-band contamination.
Note (2): Inferred from XSPEC spectral fit.
Note (3): Derived from the single-dish 13CO map by Bally et al.
(1987ApJ...312L..45B 1987ApJ...312L..45B).
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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 I4 --- COUPW COUP number (West component)
6- 9 I4 --- COUPE COUP number (East component)
11- 13 F3.1 arcsec Sep Separation between the West and East components
15- 17 F3.1 arcmin OffAxis Off-Axis angle
19- 21 F3.1 keV E-W Median energy of West component (4)
22 A1 --- --- [-]
23- 25 F3.1 keV E-E Median energy of West component (4)
27- 30 F4.1 [cm-2] NH-W Log of the West hydrogen column density
31 A1 --- --- [-]
32- 35 F4.1 [cm-2] NH-E ? Log of the East hydrogen column density
37- 41 A5 --- NIR-W NIR crossid for the West component (1)
43- 47 A5 --- Opt-W Optical crossid for the West component (2)
49- 53 A5 --- NIR-E NIR crossid for the East component (1)
55- 59 A5 --- Opt-E Optical crossid for the East component (2)
61- 63 A3 --- Cl-W Membership classification of West component (3)
65- 67 A3 --- Cl-E Membership classification of East component (3)
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Note (1): Near-infrared counterpart in the VLT catalog of the first COUP
component (McCaughrean et al. 2005, in preparation).
Note (2): Optical counterpart of the first COUP component (Hillenbrand 1997,
Cat. J/AJ/113/1733 ; Herbst et al. 2002, Cat. J/A+A/396/513).
Note (3): Proposed class of the COUP component, defined as follows:
M = established member,
NM = new member based on variability,
NM? = possible new member based on high source density.
Note (4): corrected for background
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- COUP COUP Sequence number (COUP NNNN in Simbad)
6- 26 A21 --- Name IAU identification (COUP JHHMMSS.s+DDMMSS)
28- 31 F4.1 [cm-2] NH Log of the source hydrogen column density
33- 37 F5.2 [10-7W] LX Observed source luminosity, in units of ergs/s
(1)
39- 54 A16 --- NIRName NIR counterpart
56- 60 F5.2 mag Jmag J band magnitude (2)
62- 66 F5.2 mag Hmag H band magnitude (2)
68- 72 F5.2 mag Ksmag Ks band magnitude (2)
74- 77 A4 --- [H97b] Optical counterpart identifier
(from Hillenbrand, 1997 Cat. J/AJ/113/1733)
79- 82 F4.1 mag Vmag ? V band magnitude
84- 87 F4.1 mag Imag I band magnitude
89- 91 F3.1 mag AV ? Visual extinction from Hillenbrand (1997,
Cat. J/AJ/113/1733)
93- 97 F5.2 --- logLX/Lbol ? X-ray emissivity log(LX/Lbol) in the
total 0.5-8keV band from Getman et al.
(2005, Cat. J/ApJS/160/319)
99-100 I2 --- Prob Proper motion membership probability
from Jones & Walker (1988AJ.....95.1755J 1988AJ.....95.1755J)
102-109 A8 --- SpType Spectral type (3)
111 A1 --- Field [F] Field star candidate
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Note (1): The value of LX was calculated assuming distance of 450pc, which will
be incorrect for field stars.
Note (2): For the inner region, these are from the VLT merged catalog of
McCaughrean et al. (2005, in preparation), while for the outer
region they are from the 2MASS catalog.
Note (3): Spectral type from the optical spectroscopy of Hillenbrand
(1997, Cat. J/AJ/113/1733) updated as described in Getman et al.
(2005, Cat. J/ApJS/160/319).
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Global Notes:
Note (G1): Proposed membership classification, defined as follows:
OMC = Orion Molecular Cloud
EG = Extragalactic
ONC = Orion Nebula Cluster
HH = Herbig-Haro objects
Unc. = Uncertain
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 20-Dec-2005