J/AJ/131/2164 X-ray sources in RMC 136 (Townsley+, 2006)
A Chandra ACIS study of 30 Doradus.
II. X-ray point sources in the massive star cluster R136 and beyond.
Townsley L.K., Broos P.S., Feigelson E.D., Garmire G.P., Getman K.V.
<Astron. J., 131, 2164-2184 (2006)>
=2006AJ....131.2164T 2006AJ....131.2164T
ADC_Keywords: X-ray sources ; Magellanic Clouds ; Clusters, open ; H II regions
Keywords: H II regions - Magellanic Clouds -
open clusters and associations: individual (R136) -
stars: Wolf-Rayet - X-rays: individual (30 Doradus) - X-rays: stars
Abstract:
We have studied the X-ray point-source population of the 30 Doradus
(30 Dor) star-forming complex in the Large Magellanic Cloud using high
spatial resolution X-ray images and spatially resolved spectra
obtained with the Advanced CCD Imaging Spectrometer (ACIS) on board
the Chandra X-Ray Observatory. Here we describe the X-ray sources in a
17'x17' field centered on R136, the massive star cluster at the center
of the main 30 Dor nebula. We detect 20 of the 32 Wolf-Rayet stars in
the ACIS field. The cluster R136 is resolved at the subarcsecond level
into almost 100 X-ray sources, including many typical O3-O5 stars, as
well as a few bright X-ray sources previously reported.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 108 116 Main Chandra catalog: basic source properties
table2.dat 108 64 Tentative sources: basic properties
table3.dat 117 33 X-ray spectroscopy for photometrically selected
sources: thermal plasma fits
table4.dat 128 16 X-ray spectroscopy for photometrically selected
sources: power-law fits
table5.dat 212 88 X-ray point-source counterparts
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See also:
II/187 : 30 Doradus OB Associations (Parker 1992)
J/AJ/107/1054 : UBV photometry of the 30 Dor region (Malumuth+, 1994)
J/A+AS/143/391 : ROSAT HRI catalogue of LMC X-ray sources (Sasaki+, 2000)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- [TBF2006] Source Sequence number (1)
5- 22 A18 --- CXOUJ Source name (HHMMSS.ss+DDMMSS.s)
24- 32 F9.6 deg RAdeg Right Ascension in decimal degrees (J2000)
34- 43 F10.6 deg DEdeg Declination in decimal degrees (J2000)
45- 47 F3.1 arcsec ePos Formal 1σ radial positional error
49- 52 F4.1 arcmin theta Off-axis angle
54- 59 F6.1 ct Ncts Net full band (0.5-8keV) extracted counts
61- 64 F4.1 ct e_Ncts The 1σ error in Ncts
66- 70 F5.1 ct Bcts Estimated background counts in extraction
region
72- 77 F6.1 ct Hcts Net hard band (2-8keV) extracted counts
79- 82 F4.2 --- PSFfrac PSF fraction used to extract the source (2)
84- 87 F4.1 --- Sig Photometric significance (G1)
89 A1 --- l_Prob Limit flag on Prob
90- 94 F5.1 --- Prob Probability of non-dectection (3)
96- 97 A2 --- Anom Observational anomalies (4)
99 A1 --- Var Likelihood of displaying variability (5)
101-104 F4.1 ks ExpTime Effective exposure time (6)
106-108 F3.1 keV MedE Background-corrected median energy estimate
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Note (1): An upcoming Chandra observation of this field, with 5 times the
exposure, will result in a longer, more complete list of point
sources than what is given in this paper. Sources in table 2 are
tentative and shouldn't be considered definitive.
Note (2): Note that a reduced PSF fraction (significantly below 90%) indicates
that the source is in a crowded region.
Note (3): log(Probability) that extracted counts (full band) are solely
from background.
Note (4): Observational anomalies, defined as follows:
g = fractional time that source was on a detector (FRACEXPO) is <0.9;
e = source on field edge;
p = source piled up;
s = source on readout streak.
Note (5): No test is performed for sources with fewer than 4 total full-band
counts. No value is reported for sources in chip gaps or on field
edges. Var is defined as follows:
a = no evidence for variability;
b = possibly variable;
c = definitely variable.
Note (6): The length of time that the source would have to be observed at the
Chandra aim point in order to collect the same number of counts as
were actually obtained in the observation performed.
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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- 3 I3 --- [TBF2006] Source sequence number
5- 22 A18 --- CXOUJ Source name (HHMMSS.ss+DDMMSS.s)
24- 28 F5.1 ct Ncts Net full-band (0.5-8keV) extracted counts
30- 33 F4.1 --- Sig Photometric significance (G1)
34 A1 --- n_logNH [d] Note on logNH (1)
35- 38 F4.1 [cm-2] logNH Hydrogen column density
40- 43 F4.2 [cm-2] E_logNH ? Upper limit error on logNH
45- 48 F4.2 [cm-2] e_logNH ? Lower limit error on logNH
49 A1 --- n_kT [d] Note on kT (1)
50- 52 F3.1 keV kT Plasma energy
54- 56 F3.1 keV E_kT ? Upper limit error on kT
58- 60 F3.1 keV e_kT ? Lower limit error on kT
62- 65 F4.1 [cm-3] logEM Emission measure
67- 70 F4.2 [cm-3] E_logEM ? Upper limit error on logEM
72- 75 F4.2 [cm-3] e_logEM ? Lower limit error on logEM
77- 81 F5.2 [10-7W] logLs ? Luminosity in the soft band (0.5-2kev)
(in units of erg/s)
83- 87 F5.2 [10-7W] logLh Luminosity in the hard band (2-8keV)
(in units of erg/s)
89- 93 F5.2 [10-7W] logLhc Absorption-corrected luminosity in the
hard band (2-8keV) (in units of erg/s)
95- 99 F5.2 [10-7W] logLt Luminosity in the total band (0.5-8keV)
(in units of erg/s)
101-105 F5.2 [10-7W] logLtc ? Absorption-corrected luminosity in the
total band (0.5-8keV) (in units of erg/s)
106 A1 --- Note [eh] Problem on X-ray luminosities (2)
107-117 A11 --- Rem Remark (3)
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Note (1): These quantities were frozen in the spectral fit; results are
tentative.
Note (2): Note, defined as follows:
e = Given luminosities are incorrect for this foreground star. Its flux
can be calculated as logF=logL-47.48.
h = The fit was performed by hand, usually because the automated
fit yielded nonphysical results.
Note (3): Well-known counterparts from Table 5 are listed here for the
convenience of the reader.
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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- 3 I3 --- [TBF2006] Source sequence number
5- 22 A18 --- CXOUJ Source name (HHMMSS.ss+DDMMSS.s)
24- 29 F6.1 ct Ncts Net (0.5-8keV) extracted counts
31- 34 F4.1 --- Sig Photometric significance (G1)
36- 39 F4.1 [cm-2] logNH Column density
41- 44 F4.2 [cm-2] E_logNH ? Upper limit error on logNH
46- 49 F4.2 [cm-2] e_logNH ? Lower limit error on logNH
51- 53 F3.1 --- Gamma ? Power-law photon index
55- 58 F4.2 --- E_Gamma ? Upper limit error on Gamma
60- 63 F4.2 --- e_Gamma ? Lower limit error on Gamma
65- 68 F4.1 [ph/cm2/s] logN Power-law normalization
70- 73 F4.2 [ph/cm2/s] E_logN ? Upper limit error on logN
75- 78 F4.2 [ph/cm2/s] e_logN ? Lower limit error on logN
80- 85 F6.2 [ph/cm2/s] logFs X-ray flux in the soft band (0.5-2keV)
87- 92 F6.2 [ph/cm2/s] logFh X-ray flux in the hard band (2-8keV)
94- 99 F6.2 [ph/cm2/s] logFhc Absorption-corrected X-ray flux in the
hard band (2-8keV)
101-106 F6.2 [ph/cm2/s] logFt X-ray flux in the total band (0.5-8keV)
108-113 F6.2 [ph/cm2/s] logFtc Absorption-corrected X-ray flux in the
total band (0.5-8keV)
114 A1 --- Note [h] The fit was performed by hand (1)
115-128 A14 --- Rem Remark
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Note (1): Usually because the automated fit yielded non physical results.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- [TBF2006] Source sequence number
4 A1 --- n_[TBF2006] [g] Sequence numbers for tentative ACIS
sources (from Table 2)
5- 22 A18 --- CXOUJ Source name (HHMMSS.ss+DDMMSS.s)
24- 34 A11 arcsec Sepa Separation (1)
36- 52 A17 --- SpType Spectral type (2)
53 A1 --- n_SpType [i] Source confusion in the region means that
other spectral types are present in addition
to those listed.
54- 60 A7 --- BAT99 Match from Breysacher et al.
(1999A&AS..137..117B 1999A&AS..137..117B)
62- 65 I4 --- [P93] ? Match from Parker (1993, Cat. II/187)
66 A1 --- n_[P93] [h] Source too faint to appear in
Parker (1992, Cat. II/187)
67- 77 A11 --- MH94 Match from Malumuth et al. (1994,
Cat. J/AJ/107/1054),
Cl* NGC 2070 MH NNN in Simbad
79- 82 A4 --- [PPL2002] Match from Portegies Zwart et al.
(2002ApJ...574..762P 2002ApJ...574..762P)
84- 92 F9.6 deg RAdeg ? 2MASS Right Ascension (J2000.0)
94-103 F10.6 deg DEdeg ? 2MASS Declination (J2000.0)
104 A1 --- Note [T] The match is tentative (3)
105-212 A108 --- Com Other match, other name, comments (4)
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Note (1): Source separations are with respect to (in order of availability) MH94
(Malumuth & Heap, Cat. J/AJ/107/1054), 2MASS (Cat. II/246), or the
first entry in the "other match" column.
Note (2): From Breysacher et al. (1999A&AS..137..117B 1999A&AS..137..117B),
CD98 (1998MNRAS.296..622C 1998MNRAS.296..622C), or SIMBAD.
Note (3): Usually due to a counterpart/source separation >0.5" for R136 sources
or separation at the edge of the 90% Chandra PSF contour for sources
farther off-axis.
Note (4): Acronyms used:
1RXH = sources are from the ROSAT Source Catalog of Pointed
Observations with the High Resolution Imager, produced
by the ROSAT Science Team in 2000 (Cat. IX/28).
1XMM = source is from the XMM-Newton Serendipitous Source Catalog
version 1.0.1 produced by the XMM-Newton Survey Science Centre
Consortium in 2003 (Cat. IX/37).
1RXS = source is from the ROSAT Bright Source Catalog (Voges et al.
1999, Cat. IX/10).
MDM = sources are from Marx et al. (1997, Cat. J/A+AS/126/325).
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Global Notes:
Note (G1): Defined as Ncts/e_Ncts.
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History:
From electronic version of the journal
References:
Townsley et al., Paper I 2006AJ....131.2140T 2006AJ....131.2140T
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 14-Aug-2007