J/MNRAS/298/692 Radio Survey of X-ray sources (Fender+ 1998)
A radio survey of supersoft, persistent and transient X-ray sources in
the Magellanic Cloud
Fender R.P., Southwell K.A., Tzioumis A.K.
<Mon. Not. R. Astron. Soc. 298, 692 (1998)>
=1998MNRAS.298..692F 1998MNRAS.298..692F
ADC_Keywords: Magellanic Clouds ; Radio lines ; X-ray sources
Keywords: stars : binaries ; radio continuum : stars ; X-rays : stars ;
Magellanic clouds
Abstract:
We present a radio survey of X-ray sources in the Large and Small
Magellanic clouds with the Australia Telescope Compact Array at 6.3
and 3.5 cm. Specifically, we have observed the fields of five LMC and
two SMC supersoft X-ray sources, the X-ray binaries LMC X-1, X-2, X-3
& X-4, the X-ray transient Nova SMC 1992, and the soft gamma-ray
repeater SGR 0525-66. None of the targets are detected as point
sources at their catalogued positions. In particular, the proposed
supersoft jet source RXJ 0513-69 is not detected, placing constraints
on its radio luminosity compared to Galactic jet sources. Limits on
emission from the black hole candidate systems LMC X-1 and X-3 are
consistent with the radio behaviour of persistent Galactic black hole
X-ray binaries, and a previous possible radio detection of LMC X-1 is
found to almost certainly be due to nearby field sources. The SNR N49
in the field of SGR 0525-66 is mapped at higher resolution than
previously, but there is still no evidence for any enhanced emission
or disruption of the SNR at the location of the X-ray source.
No radio point sources were detected at any wavelength at the
catalogued locations of the target sources. In most cases a noise
level of 50 microJy or so was achieved, making the 3-sigma upper
limits very stringent indeed. The noise levels for LMC X-1 and SGR
0525-66 are considerably worse, due to their locations in radio-bright
regions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 64 28 List of images with main characteristics
fits/* . 28 Subdirectory containing the 28 FITS images
(about 240MBytes)
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- FITSfile *Name of FITS file (in subdirectory "fits")
14- 16 F3.1 GHz Frequency Observed frequency
18- 19 I2 h RAh Right Ascension J2000 pointing centre (hours)
21- 22 I2 min RAm Right Ascension J2000 (minutes)
24- 28 F5.2 s RAs Right Ascension J2000 (seconds)
30 A1 --- DE- Declination J2000 pointing centre (sign)
31- 32 I2 deg DEd Declination J2000 (degrees)
34- 35 I2 arcmin DEm Declination J2000 (minutes)
37- 40 F4.1 arcsec DEs Declination J2000 (seconds)
42- 45 I4 pix Npix *Image size
47- 50 F4.2 arcsec pixsize *Pixel size
52- 64 A13 --- Target *Name of target
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Note on FITSfile, Target:
often we offset the pointing (commonly by ± 10 arcsec in Dec) so do
not assume target will lie exactly at centre of field, but instead
check pointing centre. FITS headers give information on field and
pixel size, and in HISTORY section, on reduction process (including
phase calibration, CLEANing and the synthesised beam). Pixel values
are Jy / beam ( = flux density for a point source).
Note on Npix, pixsize: all images are squares made of square pixels,
with Y-axis directed towards North. The images are stored in
FITS format (floating-point pixel values).
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Acknowledgements: Robert P. Fender
(End) Francois Ochsenbein [CDS] 18-Jul-1998