J/ApJ/625/796 X-ray sources in the globular cluster 47 Tuc (Heinke+, 2005)
A deep Chandra survey of the globular cluster 47 Tucanae:
catalog of point sources.
Heinke C.O., Grindlay J.E., Edmonds P.D., Cohn H.N., Lugger P.M.,
Camilo F., Bogdanov S., Freire P.C.
<Astrophys. J., 625, 796-824 (2005)>
=2005ApJ...625..796H 2005ApJ...625..796H
ADC_Keywords: Clusters, globular ; X-ray sources ; Stars, variable
Keywords: globular clusters: individual (NGC 104) -
novae, cataclysmic variables - pulsars: general - stars: neutron -
X-rays: binaries
Abstract:
We have detected 300 X-ray sources within the half-mass radius (2.79')
of the globular cluster 47 Tucanae in a deep (281ks) Chandra exposure.
We perform photometry and simple spectral fitting for our detected
sources and construct luminosity functions, X-ray color-magnitude, and
color-color diagrams. Eighty-seven X-ray sources show variability on
timescales from hours to years. Thirty-one of the new X-ray sources
are identified with chromospherically active binaries from the
catalogs of Albrow and coworkers (2001, Cat. J/ApJ/559/1060). We
estimate that the total number of neutron stars in 47 Tuc is of order
300, reducing the discrepancy between theoretical neutron star
retention rates and observed neutron star populations in globular
clusters. Comprehensive tables of source properties and simple
spectral fits are provided electronically.
Description:
The data used in this paper are from the 2000 and 2002 Chandra
observations of the globular cluster 47 Tuc.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 178 300 47 Tuc basic X-ray source properties, 2002 dataset
table3.dat 177 146 47 Tuc basic X-ray source properties, 2000 dataset
table4.dat 65 32 New optical counterpart identifications
table5.dat 175 300 47 Tuc supplemental X-ray source properties,
2002 Dataset
table7.dat 125 147 Spectral Fits to 47 Tuc Sources
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See also:
J/other/Sci/292.2290 : Chandra compact binaries in 47 Tuc (Grindlay+, 2001)
J/AJ/127/1588 : 47 Tuc main-sequence star abundances (Briley+, 2004)
J/ApJ/559/1060 : Variables in 47 Tuc (Albrow+, 2001)
Byte-by-byte Description of file: table2.dat table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- [GHE2001] The WAVDETECT detection number
([GHE2001] WNNN in Simbad) (G1)
5- 19 A15 --- CXOGlb The IAU-approved source name
(CXOGlb JHHMMSS.s+DDMMSS in Simbad)
21- 22 I2 h RAh Hour of Right Ascension (J2000)
24- 25 I2 min RAm Minute of Right Ascension (J2000)
27- 32 F6.3 s RAs Second of Right Ascension (J2000)
34- 38 F5.3 s e_RAs The 1σ error in RAs
40 A1 --- DE- Sign of the Declination (J2000)
41- 42 I2 deg DEd Degree of Declination (J2000)
44- 45 I2 arcmin DEm Arcminute of Declination (J2000)
47- 51 F5.2 arcsec DEs Arcsecond of Declination (J2000)
53- 56 F4.2 arcsec e_DEs The 1σ error in DEs
58- 60 I3 arcsec Dist ? Distance from cluster center (2)
62- 65 F4.2 --- fPSF ? The point spread function fraction
67- 70 F4.2 --- fEXP ? Fractional exposure time (3)
72- 78 F7.1 ct ct1 Background-subtracted 0.5-4.5keV counts
80- 84 F5.1 ct E_ct1 Upper limit 1σ error in cts1
86- 90 F5.1 ct e_ct1 Lower limit 1σ error in cts1
92- 98 F7.1 ct ct2 Background-subtracted 0.5-1.5keV counts
100-104 F5.1 ct E_ct2 Upper limit 1σ error in cts2
106-110 F5.1 ct e_ct2 Lower limit 1σ error in cts2
112-117 F6.1 ct ct3 Background-subtracted 1.5-6keV counts
119-122 F4.1 ct E_ct3 Upper limit 1σ error in cts3
124-127 F4.1 ct e_ct3 Lower limit 1σ error in cts3
129-134 F6.1 10+23W Lum1 The 0.5-6.0keV luminosity (4)
136-139 F4.1 10+23W E_Lum1 Upper limit 1σ error in Lum1
141-144 F4.1 10+23W e_Lum1 Lower limit 1σ error in Lum1
146-151 F6.1 10+23W Lum2 The 0.5-2.5keV luminosity (4)
153-156 F4.1 10+23W E_Lum2 Upper limit 1σ error in Lum2
158-161 F4.1 10+23W e_Lum2 Lower limit 1σ error in Lum2
163-165 A3 --- Type Classification of the source (5)
166 A1 --- u_Type [?] Uncertainty flag on Type
168-173 A6 --- ONames Other names (6)
175-178 A4 --- Notes Variability or confusion notes (G2)
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Note (2): Taken to be RA=00:24:05.29, DE=-72:04:52.3; de Marchi et al.
(1996ApJ...468L..51D 1996ApJ...468L..51D).
Note (3): Compared to the nominal exposure time of 72155 seconds.
Note (4): In units of 1030erg/s. See text for luminosity conversion.
Assuming a 2keV VMEKAL spectrum, an absorbing column of
1.3x1020cm-2, and a distance of 4.85kpc, we derive conversion
factors of 5.93x1036 and 4.94x1036erg.cm2/ph to convert
from photon flux to unabsorbed X-ray luminosity in the 0.5-6.0
and 0.5-2.5keV energy bands, respectively. To recover the
directly measured photon fluxes in photons/cm2/s, the reader
may divide the quoted luminosities by these factors.
Note (5): Classification of the source, defined as follows:
AB = active binary
CV = cataclysmic variable
qLX = low-mass X-ray binaries containing accreting neutron stars;
AGB = an AB from Albrow et al. (2001, Cat. J/ApJ/559/1060) identified with
an X-ray source in this work.
MSP = millisecond pulsar
Note (6): Other names, defined as follows:
AKO 9 = Auriere et al. (1989A&A...214..113A 1989A&A...214..113A);
ROSAT X # = Verbunt & Hasinger (1998A&A...336..895V 1998A&A...336..895V);
MSP lettering = Camilo et al. (2000ApJ...535..975C 2000ApJ...535..975C),
Freire et al. (2001MNRAS.326..901F 2001MNRAS.326..901F), and
Edmonds et al. (2002ApJ...564L..17E 2002ApJ...564L..17E, 2002ApJ...579..741E 2002ApJ...579..741E).
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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 --- [GHE2001] The WAVDETECT detection number
([GHE2001] WNNN in Simbad) (G1)
5- 19 A15 --- CXOGlb The IAU-approved source name
(CXOGlb JHHMMSS.s+DDMMSS in Simbad)
21- 27 A7 --- OName Name from 2001ApJ...559.1060A 2001ApJ...559.1060A
29- 34 F6.3 arcsec oRA Offset from aligned Chandra Right Ascension
36- 41 F6.3 arcsec oDE Offset from aligned Chandra Declination
43- 46 F4.2 --- Sep Separation/Error
48- 60 A13 --- VarType Variability type according to Albrow et al.,
2001, Cat. J/ApJ/559/1060
62- 65 F4.2 d Per Period
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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- 3 I3 --- [GHE2001] The WAVDETECT detection number
([GHE2001] WNNN in Simbad) (G1)
5- 19 A15 --- CXOGlb The IAU-approved source name
(CXOGlb JHHMMSS.s+DDMMSS in Simbad)
21- 24 F4.2 --- fPSF1 The 1.5keV point-spread function fraction
26- 29 F4.2 --- fEXP1 Fractional exposure time (2)
31- 37 F7.1 ct Ct1 Background-subtracted 0.3-8.0keV counts
39- 43 F5.1 ct E_Ct1 Upper limit 1σ error in Cts1
45- 49 F5.1 ct e_Ct1 Lower limit 1σ error in Cts1
51- 57 F7.1 ct Ct2 Background-subtracted 0.3-0.8keV counts
59- 63 F5.1 ct E_Ct2 Upper limit 1σ error in Cts2
65- 69 F5.1 ct e_Ct2 Lower limit 1σ error in Cts2
71- 77 F7.1 ct Ct3 Background-subtracted 0.8-2.0keV counts
79- 83 F5.1 ct E_Ct3 Upper limit 1σ error in Cts3
85- 89 F5.1 ct e_Ct3 Lower limit 1σ error in Cts3
91- 96 F6.1 ct Ct4 Background-subtracted 2.0-8.0keV counts
98-101 F4.1 ct E_Ct4 Upper limit 1σ error in Cts4
103-106 F4.1 ct e_Ct4 Lower limit 1σ error in Cts4
108-112 F5.2 --- HR1 The first hardness ratio,
HR1=(Ct4-Ct3)/(Ct4+Ct3) (3)
114-117 F4.2 --- E_HR1 Upper limit 1σ error in HR1
119-122 F4.2 --- e_HR1 Lower limit 1σ error in HR1
124-128 F5.2 --- HR2 The second hardness ratio,
HR2=(Ct3-Ct2)/(Ct3+Ct2) (3)
130-133 F4.2 --- E_HR2 Upper limit 1σ error in HR2
135-138 F4.2 --- e_HR2 Lower limit 1σ error in HR2
140-144 F5.2 --- HR3 The third hardness ratio,
HR3=(Ct4-Ct2)/(Ct4+Ct2) (3)
146-149 F4.2 --- E_HR3 Upper limit 1σ error in HR3
151-154 F4.2 --- e_HR3 Lower limit 1σ error in HR3
156-161 F6.2 --- HR4 The fourth hardness ratio,
HR4=Ct(0.5-1.5keV)/Ct(1.5-6keV) (3)
163-168 F6.2 --- E_HR4 Upper limit 1σ error in HR4
170-175 F6.2 --- e_HR4 Lower limit 1σ error in HR4
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Note (2): Compared to the nominal exposure time of 281074 seconds.
Note (3): HR1, HR2 and HR3 defined as (H-S)/(H+S), HR4 defined as S/H.
For HR1, H=2.0-8.0keV, S=0.8-2.0keV; for HR2, H=0.8-2.0,
S=0.3-0.8keV; for HR3, H=2.0-8.0keV, S=0.3-0.8keV; for HR4,
H=1.5-6.0keV, S=0.5-1.5keV.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- [GHE2001] The WAVDETECT detection number
([GHE2001] WNNN in Simbad) (G1)
5- 19 A15 --- CXOGlb IAU-approved source name
(CXOGlb JHHMMSS.s+DDMMSS in Simbad)
21- 27 F7.1 ct Cts Background-subtracted 0.3-8.0keV counts
29- 33 F5.1 10+20cm-2 NH VMEKAL hydrogen column density fit (2)
35- 39 F5.1 10+20cm-2 E_NH ? Upper limit 1σ error in NH
41- 44 F4.1 10+20cm-2 e_NH ? Lower limit 1σ error in NH
46- 49 F4.1 keV kT VMEKAL temperature fit (2)
51- 54 F4.1 keV E_kT ? Upper limit 1σ error in kT
56- 59 F4.1 keV e_kT ? Lower limit 1σ error in kT
61- 66 F6.2 10+54cm-3 EM VMEKAL emission measure fit (2)
68- 76 F9.2 10+54cm-3 E_EM ? Upper limit 1σ error in EM
78- 82 F5.2 10+54cm-3 e_EM ? Lower limit 1σ error in EM
84- 90 F7.2 10+23W LumX Absorbed 0.5-6keV luminosity (3)
92- 96 F5.2 10+23W E_LumX ? Upper limit 1σ error in LumX
98-102 F5.2 10+23W e_LumX ? Lower limit 1σ error in LumX
104-110 F7.2 10+23W LumXun Unabsorbed 0.5-6keV luminosity (4)
112-120 A9 --- chi2 The χ2ν/ν value (5)
122-125 A4 --- Notes Notes Variability or confusion notes (G2)
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Note (2): Spectral fits use an absorbed thermal plasma VMEKAL model, with
abundances set to those of 47 Tuc (see section 7).
Note (3): In units of 1030erg/s.
Note (4): Fitted NH and should be treated with skepticism.
In units of 1030erg/s.
Note (5): When chi2>2, no errors are calculated for spectral parameters;
otherwise 1σ errors are quoted.
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Global Notes
Note (G1): Following the detection and naming convention systems of
Grindlay et al. (2001, Cat. J/other/Sci/292.2290);
Grindlay et al. (2002ApJ...581..470G 2002ApJ...581..470G),
Edmonds et al. (2003ApJ...596.1177E 2003ApJ...596.1177E),
Edmonds et al. (2003ApJ...596.1197E 2003ApJ...596.1197E)
for sources detected in the 2000 dataset (up to W184), and adding new
numbers above W184 for new detections.
Note (G2): Variability or confusion notes, defined as follows:
Y = 99.9% confidence variability on years timescale;
D = 99.9% confidence variability on days timescale;
H = 99.9% confidence variability on hours timescale;
D? = 99% confidence variability on days timescale;
H? = 99% confidence variability on hours timescale;
t = note detected in the 2002 data; 2 of these may be spurious detections;
c = source may suffer from confusion;
m = source identified manually, rather than by WAVDETECT.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 23-Nov-2005