J/ApJ/600/716 NGC 5128 Chandra X-ray point sources (Minniti+, 2004)
Optical counterparts of X-ray point sources observed by Chandra in NGC 5128:
20 new globular cluster X-ray sources.
Minniti D., Rejkuba M., Funes J.G., Akiyama S.
<Astrophys. J., 600, 716-728 (2004)>
=2004ApJ...600..716M 2004ApJ...600..716M
ADC_Keywords: Clusters, globular ; X-ray sources ; Photometry
Keywords: galaxies: individual (Centaurus A, NGC 5128) -
globular clusters: general - X-rays: galaxies - X-rays: stars
Abstract:
Very Large Telescope images in BVI are used to identify the optical
counterparts to bright Chandra X-ray points sources discovered by
Kraft and coworkers (2001, Cat. J/ApJ/560/675). Of a total of 111
X-ray point sources with LX>2x1036erg/s present in a 56arcmin2
field centered on this galaxy, 58 have optical counterparts. On the
basis of the sizes, optical magnitudes, and colors, 20 new globular
cluster counterparts of X-ray sources are identified, and three are
identified on the basis of their sizes. This brings the total number
of globular cluster X-ray sources in this galaxy to 33 and establishes
that 30% of the X-ray point sources in NGC 5128 are associated with
globular clusters.
Description:
The images of the inner regions of NGC 5128 were taken from the
European Southern Observatory (ESO) Archive. The 300s image in the
B-band filter, 240s image in the V-band filter, and 300s image in
the I-band filter covering the central 6.8'x6.8' of NGC 5128 were
acquired with FORS2 at the ESO VLT Unit Telescope 4 (Kueyen).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 102 97 Optical Identifications of NGC 5128 X-Ray Point
Sources
table2.dat 100 14 Additional Optical Identifications of NGC 5128
X-Ray Point Sources
table3.dat 77 33 NGC 5128 Globular Cluster X-Ray Sources
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See also:
J/ApJ/560/675 : Chandra X-ray point sources in Cen A (Kraft+, 2001)
J/A+A/369/812 : UVKs photometry of NGC 5128 globular clusters (Rejkuba, 2001)
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 --- [MRF2004] Sequential number
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 15 F5.2 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 28 F5.2 arcsec DEs Declination (J2000)
30- 39 E10.3 10-7W LX316 ? X-ray luminosity in the 0.4-10keV band,
on 5 Dec. 1999 (1)
41- 49 E9.3 10-7W LX962 ? X-ray luminosity in the 0.4-10keV band,
on 17 May 2000 (1)
51- 54 I4 pix Xpos ? X position
56- 59 I4 pix Ypos ? Y position
61- 65 F5.2 mag Bmag ? B magnitude from ESO VLT
67- 70 F4.2 mag e_Bmag ? rms uncertainty on Bmag
72- 76 F5.2 mag Vmag ? V magnitude from ESO VLT
78- 81 F4.2 mag e_Vmag ? rms uncertainty on Vmag
83- 87 F5.2 mag Imag ? I magnitude from ESO VLT
89- 92 F4.2 mag e_Imag ? rms uncertainty on Imag
94-113 A20 --- Com Comments (2)
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Note (1): Luminosities from Kraft et al., 2001, Cat. J/ApJ/560/675
Note (2): Notes are the following:
Sat.: saturated
FGS: foreground star
GC: globular cluster
GC?: possible globular cluster
Hα: detected in Hα
FC: faint optical counterpart detected in VLT images.
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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- 5 A5 --- GC Globular cluster designation (1)
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 17 F5.2 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 30 F5.2 arcsec DEs Declination (J2000)
32- 39 E8.3 10-7W LX316 ? X-ray luminosity in the 0.4-10keV band,
on 5 Dec. 1999 (2)
41- 48 E8.3 10-7W LX962 ? X-ray luminosity in the 0.4-10keV band,
on 17 May 2000 (2)
50- 54 F5.2 mag Bmag ? B magnitude from ESO VLT
56- 60 F5.2 mag Vmag ? V magnitude from ESO VLT
62- 66 F5.2 mag Imag ? I magnitude from ESO VLT
68- 70 A3 --- Spectrum [Yes ]
72- 75 A4 --- Com Comments (3)
77 A1 --- n_GC [*] *: Individual note (4)
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Note (1): Cluster designations:
NNN: [MRF2004] NNN (this paper)
GNNN: [HGH92] GNNN (Harris et al., 1992AJ....104..613H 1992AJ....104..613H)
fN.NN: [R2001b] fN.GCNN (Rejkuba, 2001, Cat. J/A+A/369/812)
Note (2): Luminosities from Kraft et al., 2001, Cat. J/ApJ/560/675
Note (3): Notes are the following:
Sat.: saturated
GC?: no colors available
H92: Harris et al., 1992AJ....104..613H 1992AJ....104..613H
M96: Minniti et al., 1996ApJ...467..221M 1996ApJ...467..221M
R01: Rejkuba, 2001, Cat. J/A+A/369/812
Note (4): *: Source 53 is not matched in our frames; the GC association
is from Kraft et al., 2001, Cat. J/ApJ/560/675
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History:
From electronic version of the journal
(End) James Marcout, Patricia Vannier [CDS] 16-Mar-2004