J/ApJ/586/814 NGC 4472 Chandra/HST study (Maccarone+, 2003)
The low-mass X-ray binary-globular connection.
II. NGC 4472 X-ray source properties and source catalogs.
Maccarone T.J., Kundu A., Zepf S.E.
<Astrophys. J. 586, 814 (2003)>
=2003ApJ...586..814M 2003ApJ...586..814M
ADC_Keywords: Galaxies, photometry ; X-ray sources ; Cross identifications ;
Clusters, globular
Keywords: galaxies: general - galaxies: individual (NGC 4472) -
galaxies: star clusters - globular clusters: general -
X-rays: binaries - X-rays: galaxies
Abstract:
We present the results of a Chandra/Hubble Space Telescope (HST) study
of the point sources of the Virgo Cluster giant elliptical galaxy NGC
4472. We identify 144 X-ray point sources outside the nuclear region,
72 of which are located within the HST fields. The optical data show
1102 sources, of which 829 have colors consistent with being globular
clusters (with only four in the restricted central 10" region). Thirty
matches are found between the two lists - these are likely to be
low-mass X-ray binaries (LMXBs) associated with globular clusters,
while ∼42 of the X-ray sources have no optical counterparts to V≲25
and I≲24, indicating that they are likely to be predominantly LMXBs
in the field star population with a small amount of possible
contamination from background active galactic nuclei. Thus
approximately 40% of the X-ray sources are in globular clusters
and 4% of the globular clusters contain X-ray sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 147 The X-ray Source List
table2.dat 75 1102 The Optical Source List
table3.dat 144 30 X-Ray/HST Matches
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See also:
J/A+AS/127/367 : Virgo Photometry Catalogue (VPC) (Young+ 1998)
J/A+A/402/37 : UV to radio SED of galaxies in Virgo cluster (Boselli+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- XID X-ray catalog Number, [MKZ2003] XID NNN
5- 10 A6 --- --- [CXOMKZ]
12- 26 A15 --- CXOMKZ CXOMKZ Source Name (JHHMMSSs+DDMMSS)
28- 31 F4.2 --- Gamma Spectral index in photon space
33- 37 F5.2 --- EGamma ? 90% error in the positive direction (G1)
39- 43 F5.2 --- eGamma ? 90% error in the negative direction (G1)
45- 52 E8.2 mW/m2 SFlux The (0.5-2.0keV) X-ray model flux (G2)
54- 61 E8.2 mW/m2 HFlux The (2.0-8.0keV) X-ray model flux (G2)
63- 70 E8.2 10-7W XLum The (0.5-8.0keV) X-ray luminosity (G2)
72- 76 F5.1 --- Chi2 The chi2 of the model fit
78- 79 I2 --- DOF Degrees of freedom
81 A1 --- GR [YN] Good region flag (3)
83 A1 --- HST HST region flag (4)
85- 88 I4 --- OID ? The optical catalog number,
[MKZ2003] OID NNNN (5)
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Note (3): Y indicates the source is outside the central 10" region
associated with nuclear emission.
Note (4): Y indicates the source is in one or more of the HST
observation regions.
Note (5): Refers to the catalog number in table 3.
A blank indicates the source has no counterpart in the HST data set.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- OID Optical catalog number, [MKZ2003] OID NNNN
6- 7 I2 h RAh Right Ascension (J2000)
9- 10 I2 min RAm Right Ascension (J2000)
12- 15 F4.1 s RAs Right Ascension (J2000)
17 A1 --- DE- Declination (J2000)
18 I1 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 26 F4.1 arcsec DEs Declination (J2000)
28- 32 F5.2 mag Vmag The V band magnitude
34- 37 F4.2 mag e_Vmag Error in Vmag
39- 43 F5.2 mag Imag The I band magnitude
45- 48 F4.2 mag e_Imag Error in Imag
50- 53 F4.2 mag V-I The V-I color
55- 58 F4.2 mag e_V-I Error in V-I
60- 63 F4.1 arcsec HLRad Half-light radius
65- 67 F3.1 arcsec e_HLRad Error in HLRad
69 A1 --- CX [YN] Chandra FOV flag (1)
71 A1 --- GC [YN] Globular cluster color flag (2)
73- 75 I3 --- XID ? X-ray counterpart ID number,
[MKZ2003] XID NNN (3)
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Note (1): Y indicates the source is in the Chandra field of view
Note (2): Y indicates the source has colors consistent with globular
clusters (0.8<V-I<1.2)
Note (3): Refers to the catalog number in table 1. A blank indicates
the source has no counterpart in the Chandra data set.
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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 --- XID X-ray catalog number, [MKZ2003] XID NNN
5- 10 A6 --- --- [CXOMKZ]
12- 26 A15 --- CXOMKZ CXOMKZ source name (JHHMMSSs+DDMMSS)
28- 31 F4.2 --- Gamma Best-fitting power-law spectral index
33- 36 F4.2 --- EGamma ? 90% error in the positive direction (G1)
38- 41 F4.2 --- eGamma ? 90% error in the positive direction (G1)
42 A1 --- n_Gamma [fb] Note on Gamma (1)
44- 51 E8.2 mJy SFlux (0.5-2.0keV) X-ray model flux (G2)
53- 60 E8.2 mJy HFlux (2.0-8.0keV) X-ray model flux (G2)
62- 69 E8.2 10-7W XLum (0.5-8.0keV) X-ray luminosity (G2)
71- 74 F4.1 --- Chi2 chi2 value of the spectral fit
76- 77 I2 --- DOF Degree of freedom of the spectral fit
79- 82 I4 --- OID Optical catalog number, [MKZ2003] OID NNNN
84- 85 I2 h RAh Right ascension (J2000)
87- 88 I2 min RAm Right ascension (J2000)
90- 93 F4.1 s RAs Right ascension (J2000)
95 A1 --- DE- Declination sign (J2000)
96 I1 deg DEd Declination (J2000)
98- 99 I2 arcmin DEm Declination (J2000)
101-104 F4.1 arcsec DEs Declination (J2000)
106-110 F5.2 mag Vmag V magnitude
112-115 F4.2 mag e_Vmag rms uncertainty on Vmag
117-121 F5.2 mag Imag I magnitude
123-126 F4.2 mag e_Imag rms uncertainty on Imag
128-131 F4.2 mag V-I V-I colour index
133-136 F4.2 mag e_V-I rms uncertainty on V-I
138-141 F4.2 --- HLRad Half-light radius of the optical counterpart
142-144 F3.1 --- e_HLRad rms uncertainty on HLRad
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Note (1): Note on Gamma:
f: fixed, b: bad fit
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Global notes:
Note (G1): For small numbers of channels, Gamma is frozen to 2.0
and no errors are given. There are also no errors for sources
with Chi2/DOF>2.0.
Note (G2): Flux comes from the flux command in XSPEC. Luminosity
comes from assuming isotropic emission and a distance of 16Mpc,
and correcting flux for absorption.
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History:
From electronic version of the journal
References:
Kundu et al. Paper I 2002ApJ...574L...5K 2002ApJ...574L...5K
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 22-May-2003