SIMBAD references

The binary pulsar system Swift J1843.5-0343 (Krimm et al, ATel #3109; Strohmayer

& Markwardt, ATel #3121) was observed with Swift starting at 2011 Feb 15

00:27:25 UT for 1.9 ksec in PC mode and starting at 2011 Feb 15 03:46:37 for 2.0 ksec in WT mode. A point source was found in the Swift/XRT at at the astrometrically corrected (utilizing the method of Evans et al, 2009, MNRAS, 397, 1177) location:

RA (J2000): 18 43 34.75 (280.89481 deg)

Dec (J2000): -03 42 56.6 (-3.71571 deg)

90% Error radius: 2.7"

The faintness of the source (mean of 0.038 ± 0.024 cts/s in 0.3-10 keV) makes spectral fitting difficult. Freezing the photon index at 2, gives an absorption

of N_H = 2.2 (+1.0/-0.7) x 10^23 erg/s/cm-2 for the PC mode data.

No source was found within the XRT error circle in UVOT uvw1 images, which is consistent with the large extinction in this direction.

We note that at the time of discovery (2011 Jan 9), Swift J1843.5-0343 was too near the Sun for Swift XRT or UVOT observations. Observations were carried out as soon as the source became visible. Since Feb 3, the source has been below the detection threshold of Swift/BAT.