J/ApJ/574/258 X-ray-emitting young stars in the Orion nebula (Feigelson+, 2002)
X-ray-emitting young stars in the Orion nebula.
Feigelson E.D., Broos P., Gaffney III J.A., Garmire G., Hillenbrand L.A.,
Pravdo S.H., Townsley L., Tsuboi Y.
<Astrophys. J. 574, 258 (2002)>
=2002ApJ...574..258F 2002ApJ...574..258F
ADC_Keywords: Clusters, open ; Stars, early-type ; X-ray sources
Keywords: open clusters and associations: individual (Orion Nebula Cluster) -
stars: activity - stars: early-type - stars: low-mass, brown dwarfs -
stars: pre-main-sequence - X-rays: stars
Abstract:
The Orion Nebula Cluster (ONC) and the molecular cloud (OMC) in its
vicinity have been observed with the ACIS-I detector on board the
Chandra X-ray Observatory with 23hr exposure in two observations, on
1999 October 12 and 2000 April 1. We detect 1075 X-ray sources, most
with sub-arcsecond positional accuracy. Ninety-one percent of the
sources are spatially associated with known stellar members of the
cluster, and an additional 7% are newly identified deeply embedded
cloud members.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 141 1075 ACIS ONC sources and stellar counterparts
notes2.dat 80 304 Individual notes to table2.dat
table3.dat 120 1075 X-ray properties of ONC sources
notes3.dat 80 461 Individual notes to table3.dat
table4.dat 68 101 X-Ray Sources without Stellar Identifications
table5.dat 117 52 High- and Intermediate-Mass ONC Stars
table6.dat 94 30 X-Ray Detections of Very Low-Mass ONC Objects
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See also:
J/ApJ/437/361 : Einstein survey of the Orion nebula region (Gagne+ 1994)
J/ApJ/584/911 : X-rays in the Orion nebula cluster (Feigelson+, 2003)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- [FBG2002] Source number
5 A1 --- n_[FBG2002] [*] *: note in notes2.dat file
7- 21 A15 --- CXOONCJ IAU designation
24- 31 F8.5 deg RAdeg Right ascension in decimal degrees (J2000)
34- 41 F8.5 deg DEdeg Declination in decimal degrees (J2000)
42- 46 F5.1 arcmin Offaxis Offaxis angle
49- 53 A5 --- Prev [a-f ] Previous X-ray detections (2)
56- 64 A9 --- ID Stellar identification (3)
67- 69 F3.1 arcsec Sep ? Separation between source and stellar ID
72- 76 F5.3 [K] logTeff ? Log effective temperature
79- 83 F5.2 [solLum] logLbol ? Log bolometric luminosity
85- 89 F5.2 mag AV ? Visual absorption
92- 96 F5.2 [solMass] logM ? Log mass
99-102 F4.2 [yr] logt ? Log age
105-109 F5.2 mag DelK ? K-band excess
111-119 A9 --- Other Other stellar properties (4)
120-124 F5.2 d Period ? Rotational period
126-128 A3 --- r_Period Reference for Period (5)
130-135 A6 --- Note Notes to Table 2 (6)
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Note (2): Previous X-ray source:
a = Einstein Observatory
b = ROSAT PSPC
c = ROSAT HRI
d = ASCA
e = Chandra ACIS-I
f = Chandra ACIS-S3
Note (3): Stellar identification use the following acronyms:
CHS = Carpenter et al., 2001, Cat. J/AJ/121/3160
H = Hillenbrand, 1997, Cat. J/AJ/113/1733
HC = Hillenbrand & Carpenter, 2000, Cat. J/ApJ/540/236
JW = Jones & Walker, 1988AJ.....95.1755J 1988AJ.....95.1755J
P = Parenago, 1954TrSht..25....1P 1954TrSht..25....1P
PSH = Prosser et al., 1994ApJ...421..517P 1994ApJ...421..517P
Note (4): Stellar properties use the following abbreviations:
FIR = mid- or far-infrared source
HH = Herbig-Haro object of host star
L = L-band excess
N = N-band excess
pd = proplyd and/or disk imaged
r = radio continuum source
wc = star with wind collision fronts
Note (5): Period references use the following symbols:
C = Carpenter et al., 2001, Cat. J/AJ/121/3160
H = Herbst et al., 2000AJ....119..261H 2000AJ....119..261H, 2001ApJ...554L.197H 2001ApJ...554L.197H
S = Stassun, 1999, Cat. J/AJ/117/2941
Note (6): Notes:
id = Stellar identification
p = Rotational period
x = X-ray image
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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 --- [FBG2002] Source number
5 A1 --- n_[FBG2002] [*] *: note in notes3.dat file
7- 21 A15 --- CXOONCJ IAU designation
24- 28 I5 ct Cxtr Extracted X-ray counts
31- 32 I2 ct Bxtr ? Background X-ray counts
35- 38 F4.1 arcsec Rxtr ? Extraction radius
41- 44 F4.2 --- fPSF Point spread function fraction
47- 51 F5.1 ct/s CR1 ? Count rate, first observation
54- 58 F5.1 ct/s CR2 ? Count rate, second observation
61- 66 A6 --- Var Variability class (G1)
69 A1 --- l_logNH Limit flag on logNH
70- 73 F4.1 [cm-2] logNH ? Log hydrogen column density
76 A1 --- l_kT Limit flag on kT
77- 80 F4.1 keV kT ? Plasma energy (1 temperature model) or
first plasma energy (2 temperature model)
81 A1 --- --- [/] Dash when 2 temperature model
82 A1 --- l_kT2 Limit flag on kT2
83- 86 F4.1 --- kT2 ? Second plasma energy value
(2 temperature model)
88 A1 --- SpFlag [*] Spectral feature flag (2)
90 A1 --- l_logLs Limit flag on logLs
91- 94 F4.1 [10-7W] logLs ? Log soft band X-ray luminosity
96 A1 --- l_logLh Limit flag on logLh
97-100 F4.1 [10-7W] logLh ? Log hard band X-ray luminosity
103-106 F4.1 [10-7W] logLt ? Log total band X-ray luminosity
109-112 F4.1 [10-7W] logLc ? Log absorption-corrected X-ray luminosity
115-117 A3 --- Note Notes (3)
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Note (2):
for faint sources, logNH and kT are highly uncertain and are
used only as rough characterizations of spectral shape.
Note (3): the following symbols are used:
f = faint source warning (spectral parameters are only used as a
spline fit for obtaining logLt)
p = photon pileup warning
s = spectral issue
v = variability issue
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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 --- [FBG2002] Source number
5 A1 --- n_[FBG2002] [abc] Note on [FBG2002] (1)
7- 21 A15 --- CXOONCJ IAU designation
23- 26 I4 ct Cxtr Counts in the total 0.5-8keV band from
within radius Rxtr
28- 35 A8 --- Var Variability flag (G1)
38 A1 --- l_logNH Limit flag on logNH
39- 42 F4.1 [cm-2] logNH ? Equivalent hydrogen column density of
absorbing interstellar material
for 1 temperature model only
44 A1 --- l_kT Limit flag on kT
45- 48 F4.1 keV kT ? Plasma energy (1 temperature model) or
first plasma energy value
(2 temperature model)
49 A1 --- --- [/] Dash when two-temperature fit
50 A1 --- l_kT2 Limit flag on kT2
51- 54 F4.1 keV kT2 ? Second plasma energy value
(2 temperature model)
57- 60 F4.1 [10-7W] logLt Broadband luminosity
62- 68 A7 --- Class Suggested class (3)
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Note (1): Individual notes are as follows:
a: Radio source Q, 2.5mJy at 2cm (Felli et al., 1993A&AS..101..127F 1993A&AS..101..127F).
b: This X-ray source lies 1.5" from IRc 14, a luminous mid-infrared
member of the OMC 1 cluster (Gezari et al., 1998ApJ...509..283G 1998ApJ...509..283G).
c: This X-ray source coincides with a SIMBAD listing for
Parenago 1867 (V=15.8). However, examination of the original
charts of Parenago (1954TrSht..25....1P 1954TrSht..25....1P) indicates that the
SIMBAD position is probably incorrect: Parenago 1867 corresponds
to HC 304∼3" to the south. The X-ray position is resolvable from
other stars in the region and has no counterpart with V<20 or K<18.
Note (3): Classifiation is as follows:
Embd/Bk : Heavily absorbed ACIS sources which do not coincide with
dense molecular cloud cores
OMC 1 : Embedded stars associated with the OMC 1 = Orion KL core
OMC 1N : Embedded stars associated with OMC 1N core
OMC 1S : Embedded stars associated with OMC 1S core
ONC : Orion Nebula Cluster member
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [FBG2002] ? Source number
6- 20 A15 --- CXOONCJ IAU designation
22- 27 A6 --- P/JW Parenago or JW designation
30- 44 A15 --- Name Other name
46- 50 F5.2 mag Vmag ? V magnitude
52- 59 A8 --- SpType MK Spectral type
61- 64 F4.2 [solLum] logLbol Bolometric luminosity
66- 69 F4.2 [solMass] logM Mass
71- 75 I5 ct Cxtr ? Counts in the total 0.5-8keV band from
within radius Rxtr
77- 84 A8 --- Var Variability flag (G1)
86 A1 --- l_logNH Limit flag on logNH
87- 91 F5.2 [cm-2] logNH ? Equivalent hydrogen column density of
absorbing interstellar material for
one-temperature plasma model
93- 95 F3.1 keV kT ? Plasma energy ( 1 temperature model)
or first value of plasma energy
(2 temperature model)
96 A1 --- --- [/] Dash when 2 temperature model
97 A1 --- l_kT2 Limit flag on kT2
98- 99 I2 keV kT2 ? Second plasma energy value
(2 temperature model)
101 A1 --- l_logLs Limit flag on logLS
102-106 F5.2 [10-7W] logLs ? Softband luminosity
107 A1 --- l_logLt Limit flag on logLt
108-112 F5.2 [10-7W] logLt Broadband luminosity
113 A1 --- l_log(Lt/Lbol) Limit flag on log(Lt/Lbol)
114-117 F4.1 [-] log(Lt/Lbol) Broadband-to-bolometric luminosity ratio
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- [FBG2002] Source number
5 A1 --- n_[FBG2002] [*] Note on [FBG2002]
7- 21 A15 --- CXOONCJ IAU designation
23- 31 A9 --- Name Other name
33- 37 F5.2 mag Kmag K magnitude
39- 43 F5.2 mag H-K ? H-K colour index
45 A1 --- l_KMAG Limit flag on KMAG
46- 49 F4.2 mag KMAG Absolute K magnitude
51 A1 --- l_Mass Limit flag on Mass
52- 55 F4.2 solMass Mass Mass
57- 59 I3 ct Cxtr Counts in the total 0.5-8keV band from
within radius Rxtr
61- 68 A8 --- Var Variability flag (G1)
69 A1 --- l_logNH Limit flag on logNH
70- 73 F4.1 [cm-2] logNH ? Hydrogen column density
75 A1 --- l_kT Limit flag on kT
76- 79 F4.1 keV kT ? Plasma energy (1 temperature model)
or first plasma energy value
(2 temperature model)
80 A1 --- --- [/] Dash when 2 temperature model
81 A1 --- l_kT2 Limit flag on kT2
82- 83 I2 keV kT2 ? Second plasma energy value
(2 temperature model)
85- 88 F4.1 [10-7W] logLt Broadband luminosity
90 A1 --- l_log(Lt/Lbol) Limit flag on log(Lt/Lbol)
91- 94 F4.1 [-] log(Lt/Lbol) Broadband-to-bolometric luminosity ratio
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Byte-by-byte Description of file: notes2.dat notes3.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- CXOONCJ Object name
16 A1 --- n_Name [*] *: the object (053520.5-05171), is not in
any tables
17- 80 A64 --- Text Text of the note
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Global notes:
Note (G1): Variability flags are:
Const. : constant
Flare : flare
LT Var. : long-term variability
Pos. fl. : possible flare
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History:
* 13-Sep-2002: From electronic version of the journal
* 17-Feb-2005: the last digit of the CXOONCJ name in the notes was
originally missing and has been added. A typo in the note of
053520.4-051714 was corrected.
* 21-Feb-2006: 3 identifications corrected in table2.dat for sources
235 (was originally JW 311),
393 (was originally PSH 93)
685 (was originally PSH 248)
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 13-Sep-2002