J/PASJ/55/161 ASCA sources in the SMC (Yokogawa+, 2003)
Review of discrete X-ray sources in the Small Magellanic Cloud :
summary of the ASCA results and implication on the recent star-forming activity.
Yokogawa J., Imanishi K., Tsujimoto M., Koyama K., Nishiuchi M.
<Publ. Astron. Soc. Jap., 55, 161 (2003)>
=2003PASJ...55..161Y 2003PASJ...55..161Y
ADC_Keywords: Magellanic Clouds ; X-ray sources
Mission_Name: ASCA
Keywords: galaxies: evolution - galaxies: individual (SMC, LMC) -
galaxies: starburst - pulsars: general - source population study -
X-rays: stars
Abstract:
We made 22 observations on the Small Magellanic Cloud (SMC) and
covered full regions of the main body and the eastern wing by the end
of the ASCA mission. We detected 106 discrete sources with a criterion
of S/N>5 and performed systematic analyses on all of the sources. We
determined the source positions with an ∼40" error radius (90%
confidence) for sources detected in the central 20' radius of the GIS.
We detected coherent pulsations from 17 sources. Among them, eight
were newly discovered during this study. We classified most of these
pulsars as X-ray binary pulsars (XBPs) based on their properties, such
as the flux variability and the existence of an optical counterpart.
We detected X-ray emission from eight supernova remnants (SNRs).
Based on these ASCA results and further information from ROSAT, SAX,
RXTE, CGRO, Chandra, and XMM-Newton, we compiled comprehensive
catalogues of discrete X-ray sources in the Small Magellanic Cloud.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 81 22 ASCA observations of the SMC region
table5.dat 237 106 ASCA catalogue of discrete X-ray sources
in the SMC region
table6.dat 126 136 Spectral parameters of the ASCA sources
table8.dat 57 36 Non-pulsating HMXBs and likely candidates
in the SMC
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See also:
J/A+AS/142/41 : SMC X-ray sources ROSAT PSPC catalogue (Haberl+, 2000)
J/A+AS/147/75 : ROSAT HRI catalogue of SMC X-ray sources (Sasaki+, 2000)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- ObsID [A-V] Observation ID
3- 12 A10 "YYYY/MM/DD" SObs.date Start of observation date (UT)
14- 15 I2 h SObs.h Start of observation date (UT)
16 A1 --- --- [:]
17- 18 I2 min SObs.m Start of observation date (UT)
20- 29 A10 "YYYY/MM/DD" EObs.date End of observation date (UT)
31- 32 I2 h EObs.h End of observation date (UT)
33 A1 --- --- [:]
34- 35 I2 min EObs.m End of observation date (UT)
37- 52 A16 --- Target Target name
55- 56 I2 h RAh Pointed direction right ascension (J2000)
58- 59 I2 min RAm Pointed direction right ascension (J2000)
61- 62 I2 s RAs Pointed direction right ascension (J2000)
64 A1 --- DE- Pointed direction declination sign (J2000)
65- 66 I2 deg DEd Pointed direction declination (J2000)
68- 69 I2 arcmin DEm Pointed direction declination (J2000)
71- 72 I2 arcsec DEs Pointed direction declination (J2000)
74- 76 I3 ks ExpGIS Exposure time with GIS
77 A1 --- n_ExpGIS [cd] Note on ExpGIS (1)
78 A1 --- --- [/]
79- 80 I2 ks ExpSIS ? Exposure time with SIS
81 A1 --- n_ExpSIS [b] Note on ExpSIS (2)
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Note (1): Note on ExpGIS:
c, d: GIS was operated with a special bit assignment of 8-6-6-5-6 (c)
or 8-8-8-5-2 (d), in which the time resolution was increased by
a factor of 64 (c) or 4 (d), at the sacrifice of a reduction of
energy resolution by a factor of 4 (c and d) and a reduction of
spatial resolution by a factor of 4 (c).
Note (2): Note on ExpSIS:
a, b: SIS was operated in 1-CCD mode (a) or 2-CCD mode (b).
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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 --- [YIT2003] Sequential number of ASCA source
4 A1 --- n_[YIT2003] [+*] Note on [YIT2003] (1)
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 sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 25 I2 arcsec DEs Declination (J2000)
27 A1 --- ObsID Observation ID (table1.dat) in which
the source was detected (2)
28 A1 --- ObsID2 Observation ID (table1.dat) in which
the source was detected (2)
29 A1 --- ObsID3 Observation ID (table1.dat) in which
the source was detected (2)
30 A1 --- --- [/]
31 A1 --- ObsID1Not Observation ID (table1.dat) in which
the source was not detected
32 A1 --- ObsID2Not Observation ID (table1.dat) in which
the source was not detected
33 A1 --- n_ObsID [j] Note on ObsID (3)
34- 39 F6.1 --- S/N Larget value of signal-to-noise ratio (4)
41- 44 I4 --- PSPC ? PSPC number of ROSAT counterpart (5)
46- 48 I3 arcsec Sep1 ? Separation between ASCA and PSPS source
49 A1 --- n_Sep1 [k] Note on Sep1 (6)
51- 53 I3 --- HRI ? HRI number of ROSAT HRI counterpart (7)
55- 57 I3 arcsec Sep2 ? Separation between ASCA and HRI source
59- 60 I2 --- IPC ? IPC number of EINSTEIN IPC counterpart (8)
62- 63 I2 arcsec Sep3 ? Separation between ASCA and IPC source
65- 71 A7 --- Class Classification (9)
73-125 A53 --- Names Other names (10)
127-237 A111 --- Com Comments (11)
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Note (1): Sources with ``*'' were detected in the inner circle of the
GIS and have an error radius of ∼40" at 90% confidence (subsubsection
3.3.1). Sources with "+" were detected in the outer ring of the GIS
and their error radius is larger.
Note (2): For sources detected multiple times, the first ID, ObsID, was
used to determine its position.
Note (3): Note on ObsID:
j: In these observations, nearby sources were too bright, thus
detection of No. 34 and No. 95 was hampered.
Note (4): The criterion of source detection is S/N>5.
Note (5): The separation angle from the central point of No. 413 and 419
in Haberl et al. (2000, Cat. J/A+AS/142/41)
Note (6): Counterpart found in the ROSAT PSPC catalogue (Haberl et al. 2000,
Cat. J/A+AS/142/41)
Note (7): Counterpart found in the ROSAT HRI catalogue (Sasaki et al., 2000,
Cat. J/A+AS/147/75)
Note (8): Counterpart found in the Einstein IPC catalogue (Wang and Wu,
1992ApJS...78..391W 1992ApJS...78..391W).
Note (9): Source class (see subsubsection 6.2.1) are as follows:
TS = thermal SNRs; subsubsection 4.2.3
RS = radio SNRs which are not classified as a thermal SNR
TSc = thermal SNR candidates; subsubsection 6.2.3
BP = X-ray binary pulsars; subsection 5.1
BPc = candidates of X-ray binary pulsar; subsubsection 6.2.3
AXP = anomalous X-ray pulsar
P = the remaining pulsars
NH = non-pulsating HMXBs; table8.dat
AGN = sources coincident with an AGN
FS = sources coincident with a foreground star
UN = unclassified sources
Note (10): Source names usually used in the literature.
References for the abbreviations are/
DDEM: Davies et al. (1976, Cat. VII/232)
IKT: Inoue et al. (1983IAUS..101..535I 1983IAUS..101..535I)
N: Henize (1956ApJS....2..315H 1956ApJS....2..315H)
SNR: Mathewson et al. (1983ApJS...51..345M 1983ApJS...51..345M, 1984ApJS...55..189M 1984ApJS...55..189M)
Note (11): Periods in square brackets were determined by others and not
detected in this work.
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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- 3 I3 --- [YIT2003] Sequential number
5- 9 F5.2 --- HR ? Hardness ratio
11- 15 F5.3 --- e_HR ? rms uncertainty on HR
17 A1 --- ObsID [A-V] Observation ID, see table1.dat
(Flux and luminosity are given for each ID)
19- 23 F5.2 --- Gamma ? Photon index
24 A1 --- n_Gamma [f] Note (2)
26 A1 --- l_Gammal Limit flag on Gamma
27- 31 F5.2 --- Gammal ? Lower value of 90% confidence limits of
Gamma
32- 36 F5.2 --- Gammau ? Upper value of 90% confidence limits of
Gamma
39- 43 F5.3 keV kT ? Temperature kT (1)
45- 49 F5.3 keV kTl ? Lower value of 90% confidence limits of kT
51- 55 F5.3 keV kTu ? Upper value of 90% confidence limits of kT
58- 63 F6.2 10+21cm-2 NH ? Absorption column density
65 A1 --- l_NHl Limit flag on NHl
66- 70 F5.1 10+21cm-2 NHl ? Lower value of 90% confidence limits of NH
72- 76 F5.1 10+21cm-2 NHu ? Upper value of 90% confidence limits of NH
78- 84 F7.3 10-15W/m2 FX ? X-ray flux in 0.7-10keV band
85 A1 --- n_FX [g] Note on FX (2)
86- 92 F7.3 10+29W LXobs ? Observed luminosity in 0.7-10keV band
93 A1 --- n_LXobs [g] Note on FX (2)
94-100 F7.3 10+29W LXcor ? Absorption-corrected luminosity
in 0.7-10keV band
101 A1 --- n_LXcor [ge] Note on FX (2)
104-153 A50 --- Note Note
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Note (1): For sources showing soft excess (Nos. 67, 90, and 94), a
two-component model consisting of a power-law (with exponential cutoff
only for No. 67) plus a blackbody was used; thus the temperature in
the table is for the blackbody component.
Note (2): Notes have the wollowing meaning:
e: The best-fit model yielded an unusually high luminosity of
∼3x1039erg/s. This is probably an artifact due to the large
values of Gamma and NH, thus we omitted it from the table.
f: A power-law model with a high-energy cutoff was used. Cut-off and
e-fold energies were respectively determined to be
6.4 (5.8-6.9)keV and 6.3 (4.4-9.4)keV.
g: The intrinsic intensity would be much higher
(see subsubsection 5.1.22).
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- [YIT2003] ? Sequential number
4- 5 I2 --- [HS2000] ? HRI (Harbel & Sasaki, 2000A&A...359..573H 2000A&A...359..573H)
number
7- 21 A15 --- Name Other name
23- 25 A3 --- --- [IKT]
26- 27 I2 --- IKT ? IKT (Inoue et al., 1983IAUS..101..535I 1983IAUS..101..535I)
number
30 A1 --- n_Name [e] Note on name (1)
33- 39 A7 --- SpType Optical identification (2)
41 A1 --- n_SpType [fg] Note on SpType (3)
43 I1 --- r_SpType Reference for spectral type (6)
45- 48 A4 --- Var [Yes ?] Variable? (4)
50 I1 --- r_Var ? Reference for variability (6)
53 A1 --- Grade Grade (5)
55- 57 A3 --- Ref References, separated by comma (6)
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Note (1): This source is designated as RX J0104.5-7121 in Haberl and Sasaki
(2000A&A...359..573H 2000A&A...359..573H) (subsection 6.4), but probably should be
RX J0104.5-7221 according to its coordinate.
Note (2): Spectral type of the optical counterpart.
Be? indicates an emission line object catalogued in Meyssonnier and
Azzopardi (1993, Cat. J/A+AS/102/451) or
Murphy and Bessell (2000, Cat. J/MNRAS/311/741).
SG indicates a supergiant counterpart.
Note (3): Notes on SpType:
f: A point-like radio source is also located in the error circle,
thus the possibility that it is an AGN remains (Haberl and
Sasaki, 2000A&A...359..573H 2000A&A...359..573H).
g: X-ray emission may be attributable to an active corona (AC) of a
late type star (Haberl & Sasaki, 2000A&A...359..573H 2000A&A...359..573H).
Note (4): For sources with the Yes sign, long-term X-ray variability
has been found.
Note (5): In table 5, we designate grade A and B sources as NH, and
grade C and D sources as NHc. Grade E sources are not regarded as
non-pulsating HMXBs (see subsubsection 6.2.1).
Note (6): References are numbered as follows:
1 = Haberl and Sasaki (2000A&A...359..573H 2000A&A...359..573H)
2 = Kahabka and Pietsch (1996A&A...312..919K 1996A&A...312..919K)
3 = Crampton et al. (1978ApJ...223L..79C 1978ApJ...223L..79C)
4 = Clark et al. (1978ApJ...221L..37C 1978ApJ...221L..37C)
5 = Whitlock and Lochner (1994ApJ...437..841W 1994ApJ...437..841W)
6 = Wang and Wu (1992ApJS...78..391W 1992ApJS...78..391W)
7 = this work
8 = Filipovic et al. (2000A&A...353..129F 2000A&A...353..129F)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 22-Sep-2003