Suzaku Observations of SGR 1900+14 and SGR 1806-20

TL;DR

This study presents Suzaku observations of two soft gamma repeaters, analyzing their spectral and timing properties, including quiescent emission spectra, detection of non-thermal components, and precise periodicities.

Contribution

First detailed Suzaku spectral and timing analysis of SGR 1900+14 and SGR 1806-20, including detection of non-thermal emission and accurate pulsation periods.

Findings

Quiescent spectra fit by two blackbodies or blackbody plus power law

Detection of non-thermal hard component consistent with INTEGRAL results

Precise measurement of pulsation periods for both SGRs

Abstract

Spectral and timing studies of Suzaku ToO observations of two SGRs, 1900+14 and 1806-20, are presented. The X-ray quiescent emission spectra were well fitted by a two blackbody function or a blackbody plus a power law model. The non-thermal hard component discovered by INTEGRAL was detected by the PIN diodes and its spectrum was reproduced by the power law model reported by INTEGRAL. The XIS detected periodicity P = 5.1998+/-0.0002 s for SGR 1900+14 and P = 7.6022+/-0.0007 s for SGR 1806-20. The pulsed fraction was related to the burst activity for SGR 1900+14.