A New Transient X-ray Pulsar in the SMC (XTE J0055-727)
ATel #214; R. H.D. Corbet (GSFC and USRA), C. B. Markwardt (GSFC and University of Maryland), M. J. Coe & W. R.T. Edge (Southampton University), S. Laycock (CfA), F. E. Marshall (GSFC)
on 16 Dec 2003; 21:33 UT
Credential Certification: Robin Corbet (corbet@gsfc.nasa.gov)
Subjects: X-ray, Binary, Transient
We have detected a new transient X-ray pulsar in the direction of the
Small Magellanic Cloud with the RXTE Proportional Counter Array. The
source was detected within the 2 degree FWZI field of view of the PCA
while pointed at R.A. = 00h53m53s, Decl. = -72o26m42s (equinox 2000.0).
Pulsations with periods of 18.37s +/- 0.01, 18.36s +/- 0.01, and
18.37s +/- 0.1 were seen on 2003 November 26, December 4 and December
11 respectively. From slews made over this region in all observations
we derive a position of R.A. = 13.84, Decl. = -72.70 (equinox 2000).
The error box is ellipsoidal with maximum extent 2 sigma statistical
errors of approximately 0.1 degrees (arc length) in R.A. and 0.06
degrees in declination. Systematic errors on the source position are
unknown but may well be significant as the region contains a complex
superposition of transient sources. The statistical error box is available
at http://lheawww.gsfc.nasa.gov/users/corbet/pulsars/xtej0055-727_ebox.ps.
Collimator response corrected count rates of 4.4 +/- 0.1 (2.2 mCrab),
5.1 +/- 0.1 (2.6 mCrab), and 3.9 +/- 0.1 (2.0 mCrab) counts/s/Proportional
Counter Unit were obtained respectively. The source was not detected in
observations made on November 18. We note the presence of the emission
line objects AzV164 and [MA93] 829 close to the center of our error box
for this source.
A list of known X-ray pulsars in the SMC is provided at: http://lheawww.gsfc.nasa.gov/users/corbet/pulsars
X-ray Pulsars in the SMC
