J/A+A/586/A81 High-mass X-ray binaries in the SMC (Haberl+, 2016)
High-mass X-ray binaries in the Small Magellanic Cloud.
Haberl F., Sturm R.
<Astron. Astrophys. 586, A81 (2016)>
=2016A&A...586A..81H 2016A&A...586A..81H (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Binaries, X-ray ; Photometry, UBVRI ;
Photometry, infrared
Keywords: Magellanic Clouds - galaxies: stellar content -
stars: emission-line, Be - stars: neutron - X-rays: binaries -
catalogs
Abstract:
The last comprehensive catalogue of high-mass X-ray binaries in the
Small Magellanic Cloud (SMC) was published about ten years ago. Since
then new such systems were discovered, mainly by X-ray observations
with Chandra and XMM-Newton. For the majority of the proposed HMXBs in
the SMC no X-ray pulsations were discovered as yet, and unless other
properties of the X-ray source and/or the optical counterpart confirm
their HMXB nature, they remain only candidate HMXBs.
From a literature search we collected a catalogue of 148 confirmed and
candidate HMXBs in the SMC and investigated their properties to shed
light on their real nature. Based on the sample of well-established
HMXBs (the pulsars), we investigated which observed properties are
most appropriate for a reliable classification. We defined different
levels of confidence for a genuine HMXB based on spectral and temporal
characteristics of the X-ray sources and colour-magnitude diagrams
from the optical to the infrared of their likely counterparts. We also
took the uncertainty in the X-ray position into account.
We identify 27 objects that probably are misidentified because they
lack an infrared excess of the proposed counterpart. They were mainly
X-ray sources with a large positional uncertainty. This is supported
by additional information obtained from more recent observations. Our
catalogue comprises 121 relatively high-confidence HMXBs (the vast
majority with Be companion stars). About half of the objects show
X-ray pulsations, while for the rest no pulsations are known as yet. A
comparison of the two subsamples suggests that long pulse periods in
excess of a few 100s are expected for the "non-pulsars", which are
most likely undetected because of aperiodic variability on similar
timescales and insufficiently long X-ray observations. The highest
X-ray variability together with the lowest observed minimum fluxes for
short-period pulsars indicate that in addition to the eccentricity of
the orbit, its inclination against the plane of the Be star
circum-stellar disc plays a major role in determining the outburst
behaviour.
The large population of HMXBs in the SMC, in particular Be X-ray
binaries, provides the largest homogeneous sample of such systems for
statistical population studies.
Description:
For an updated catalogue of HMXBs and candidates in the SMC (and the
Magellanic Bridge, which extends beyond the Eastern Wing) we compiled
lists from the literature that present properties from large samples
or searches for such systems and include the more recent discoveries
of individual objects. We collected information about the X-ray
sources as well as their companion stars from the literature and
included it in the catalogue to use it for statistical studies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 601 148 Catalogue of 148 High-Mass-X-ray Binaries
and candidates in the Small Magellanic Cloud
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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 --- Seq Source number
6- 7 I2 h RAh X-ray, Right ascension (J2000)
9- 10 I2 min RAm X-ray, Right ascension (J2000)
12- 15 F4.1 s RAs X-ray, Right ascension (J2000)
17 A1 --- DE- X-ray, Declination sign (J2000)
18- 19 I2 deg DEd X-ray, Declination (J2000)
21- 22 I2 arcmin DEm X-ray, Declination (J2000)
24- 25 I2 arcsec DEs X-ray, Declination (J2000)
27- 32 F6.1 arcsec e_Pos Uncertainty of X-ray position
34 A1 --- Xobs Origin of the X-ray coordinate (1)
36- 54 A19 --- dbib Reference (bibcode) for source discovery
56- 59 I4 --- MA93 ? Emission-line star (2)
62- 64 A3 --- ps [ps: ] X-ray modulation indicates
NS spin period
66- 68 A3 --- px [px: ] Long-term X-ray period suggests
orbital period
70- 72 A3 --- po [po: ] Period in optical suggests orbital
period
74- 76 A3 --- xv [xv ] Variability in X-rays larger than a
factor 30
78- 80 A3 --- xs [xs: ] Typical X-ray spectrum (3)
82- 84 A3 --- oi [oi: ] Optical id with high confidence
86- 88 A3 --- em [em: nem] Optical/near-IR spectral
information (4)
90- 92 A3 --- os [oxs: ] Orbital information (5)
95 I1 --- conf [1/6] Confidence class, values 1-6
98- 99 I2 h RAOh ? Optical, Right ascension (J2000) (6)
101-102 I2 min RAOm ? Optical, Right ascension (J2000)
104-108 F5.2 s RAOs ? Optical, Right ascension (J2000)
110 A1 --- DEO- Optical, Declination sign (J2000)
111-112 I2 deg DEOd ? Optical, Declination (J2000)
114-115 I2 arcmin DEOm ? Optical, Declination (J2000)
117-120 F4.1 arcsec DEOs ? Optical, Declination (J2000)
122-126 F5.2 mag Umag ? U magnitude from MCPS (7)
128-131 F4.2 mag e_Umag ? rms uncertainty on Umag
133-137 F5.2 mag Bmag ? B magnitude from MCPS (7)
139-142 F4.2 mag e_Bmag ? rms uncertainty on Bmag
144-148 F5.2 mag Vmag ? V magnitude from MCPS (7)
150-153 F4.2 mag e_Vmag ? rms uncertainty on Vmag
155-159 F5.2 mag Imag ? I magnitude from MCPS (7)
161-164 F4.2 mag e_Imag ? rms uncertainty on Imag
166-170 F5.2 mag U-B ? U-B colour index
173-176 F4.2 mag e_U-B ? rms uncertainty on U-B
178-182 F5.2 mag B-V ? B-V colour index
184-187 F4.2 mag e_B-V ? rms uncertainty on B-V
189-193 F5.2 mag V-I ? V-I colour index
195-198 F4.2 mag e_V-I ? rms uncertainty on V-I
200-204 F5.2 mag Q ? Reddening-free Q-value (8)
206-209 F4.2 mag e_Q ? rms uncertainty on Q
212-228 A17 --- 2MASS 2MASS name (9)
230-234 F5.2 mag Jmag ? J magnitude from 2MASS (10)
236-239 F4.2 mag e_Jmag ? rms uncertainty on Jmag
241-245 F5.2 mag Hmag ? H magnitude from 2MASS (10)
247-250 F4.2 mag e_Hmag ? rms uncertainty on Hmag
252-256 F5.2 mag Kmag ? K magnitude from 2MASS (10)
258-261 F4.2 mag e_Kmag ? rms uncertainty on Kmag
263-267 F5.2 mag J-H ? 2MASS J-H colour index
269-272 F4.2 mag e_J-H ? rms uncertainty on J-H
274-278 F5.2 mag H-K ? 2MASS H-K colour index
280-283 F4.2 mag e_H-K ? rms uncertainty on H-K
289-293 F5.2 mag F3.6 ? Spitzer IRAC flux at 3.6 micrometer (11)
295-298 F4.2 mag e_F3.6 ? Error flux at 3.6 micrometer
300-304 F5.2 mag F4.5 ? Spitzer IRAC flux at 4.5 micrometer (11)
306-309 F4.2 mag e_F4.5 ? Error flux at 4.5 micrometer
311-315 F5.2 mag F5.8 ? Spitzer IRAC flux at 5.8 micrometer (11)
317-320 F4.2 mag e_F5.8 ? Error flux at 5.8 micrometer
322-326 F5.2 mag F8.0 ? Spitzer IRAC flux at 8.0 micrometer (11)
328-331 F4.2 mag e_F8.0 ? Error flux at 8.0 micrometer
333-336 F4.1 arcsec dXO ? Angular distance, X-ray to optical position
338-341 F4.2 arcsec dOIR ? Angular distance,
optical to near-IR position
343-350 F8.3 s Pspin ? Neutron star spin period,
inferred from X-rays
352-358 F7.1 d Porb ? Orbital period (see flags for origin)
360-367 E8.3 mW/m2 Fmax ? Maximum observed X-ray flux (12)
369-376 E8.3 mW/m2 Fmin ? Minimum observed X-ray flux (12)
378-379 I2 --- l_Fmin [-1/1] Flag for minimum flux,
1 for upper limit (13)
381-399 A19 --- r_Fmax References for maximum X-ray flux
401-419 A19 --- r_Fmin References for minimum X-ray flux
421-427 E7.2 --- Var ? X-ray variability factor (14)
429-433 F5.1 0.1nm Ha1 ? Equivalent width of the Halpha line (15)
435-439 F5.1 0.1nm Ha2 ? Maximum equivalent width of the Halpha line
441-520 A80 --- r_Ha References for the Halpha measurements
522-601 A80 --- Com Comments with key references (bibcode)
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Note (1): Origin of the X-ray coordinate as follows:
A = ASCA
C = Chandra
E = Einstein
I = Integral
N = XMM-Newton
R = ROSAT
S = Swift
X = RXTE
When no reliable position could be determined from the non-imaging
RXTE collimator-instruments, a radius of 30 arcmin for the position
error indicates the size of the field of view.
Note (2): Identification of optical counterpart with emission-line star
from Meysonnier & Azzopardi (1993A&AS..102..451M 1993A&AS..102..451M, [MA93] NNNN).
The negative number indicates a star found in the catalogue of
Murphy & Bessell (2000MNRAS.311..741M 2000MNRAS.311..741M, [MB2000] 179).
Note (3): Power law with photon index <1.3
Note (4): Optical/near-IR spectral information as follows:
em = Balmer (Halpha) emission measured from spectrum
nem = no near-IR excess emission
Note (5): Orbital information as follows:
os = full orbital solution available
ox = assuming X-ray period as orbital period
oo = assuming optical period as orbital period
oxo = X-ray and optical period are consistent
Note (6): Coordinates of optical counterpart from Zaritsky et al.
(2002AJ....123..855Z 2002AJ....123..855Z), or - when not available there - from
Massey (2002ApJS..141...81M 2002ApJS..141...81M)
Note (7): Magnitudes of optical counterpart from the Magellanic Clouds
Photometric Survey (MCPS); Zaritsky et al. (2002AJ....123..855Z 2002AJ....123..855Z)
Note (8): Q = U-B-0.72*(B-V); Reddening-free Q-value
Note (9): Near-IR counterpart to the optical star from the Two Micron All Sky
Survey (2MASS); Skrutskie et al. (2006AJ....131.1163S 2006AJ....131.1163S)
Note (10): Near-IR magnitudes from 2MASS
Note (11): Spitzer IRAC fluxes with respective errors from the SAGE project
for a description see Meixner et al. (2006AJ....132.2268M 2006AJ....132.2268M)
Note (12): Maximum and minimum X-ray flux [erg/cm^2/s, when available in
the 0.2-10keV band. Fluxes in the SMC XMM-Newton catalogue of Sturm et al.
(2013A&A...558A...3S 2013A&A...558A...3S) are given for the 0.2 to 4.5keV band.
To convert them into the 0.2-10keV band, we multiplied them by a factor of
2.6 assuming a standard power law with photon index 0.9
(Haberl et al. 2008A&A...489..327H 2008A&A...489..327H) and a column density of 1021cm-2
(solar abundance). For Swift XRT count rates we used a flux conversion factor
of 1.1*10-10erg/cm2/ct/s
Note (13): Flag for minimum flux as follows:
1 = a non-detection with an upper limit
-1 = when unknown
0 = detection
Note (14): Ratio of maximum to minimum flux.
Note (15): Minimum value if more than one measurement is available.
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Acknowledgements:
Frank Haberl, fwh(at)mpe.mpg.de
(End) Patricia Vannier [CDS] 18-Dec-2015