SGR 1900+14
Abstract
K. Hurley, Space Sciences Laboratory, on behalf of the Ulysses Gamma-Ray Burst Team; C. Kouveliotou, Universities Space Research Association (USRA); T. Murakami, Institute of Space and Astronautical Science; and T. Strohmayer, Goddard Space Flight Center (GSFC), report on behalf of a larger collaboration: "We have derived a preliminary triangulation error box for SGR 1900+14 using bursts observed in common with Ulysses and BATSE/CGRO from May through July. The corners of the box are (equinox 2000.0): R.A. = 19h07m16s, Decl. = +9o23'.8; 19h06m52s, +9o06'.5; 19h07m45s, +9o39'.1; 19h07m21s, +9o21'.9. This error box includes the ROSAT source previously suggested as the quiescent x-ray counterpart to the soft gamma-ray repeater (Hurley et al. 1996, Ap.J. 463, L13). We observed SGR 1900+14 with the ASCA satellite in April, and find that it has a hard spectrum consistent with a power law with index 2.2, and flux 1.3 x 10E-11 erg cmE-2 sE-1 (2-10 keV). We detect coherent pulsations from the source at a high significance with a period of 5.16 s. The similarity of the period of this source to the one of 7.47 s detected from SGR 1806-20 (Kouveliotou et al. 1998, Nature 393, 235), indicates that the newly detected pulsar is the soft gamma-ray repeater. The centroid of the error box of the source is at R.A. = 19h07m14s, Decl. = +9o19'.3, close to the supernova remnant G42.8+0.6. As the source is still active, we urge monitoring at other wavelengths."
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- August 1998
- Bibcode:
- 1998IAUC.7001....1H