RXTE Detection of the Spin Period of Swift J1822.3-1606
ATel #3491; Ersin Gogus (Sabanci Univ. Istanbul), Chryssa Kouveliotou (NASA/MSFC), Tod Strohmayer (NASA/GSFC) report on behalf of a larger team
on 16 Jul 2011; 16:26 UT
Credential Certification: Ersin Gogus (ersing@sabanciuniv.edu)
Subjects: X-ray, Soft Gamma-ray Repeater
RXTE/PCA observed the new source, Swift J1822.3-1606 (Cummings et al. GCN Circ. 12159) on 2011 July 16, for 6.7 ks. We performed a timing analysis on the barycentered data and detected a coherent pulsation at 0.1185149(2) Hz corresponding to 8.4377585 s. Pulsations are clearly visible in the PCA light curve. The peak-to-peak pulsed amplitude in the 2-10 keV band is 0.41. This pulsed fraction is highly unlikely from an SGR source, and very reminiscent of the outburst onset of Swift J1626.6-5156 (Palmer et al. 2005), that is likely a Be-X-ray binary system. Alternatively, the source could be similar to the rotation powered PSR J1846-0258 (Gavriil et al. 2008), which was observed to emit SGR-like outbursts. Further multi-wavelength observations of the source are strongly encouraged to determine its nature.
