On the X-ray variability of magnetar 1RXS J170849.0-400910

We present a long-term X-ray flux and spectral analysis for 1RXS J170849.0-400910 using the Swift/X-Ray Telescope spanning over eight years from 2005 to 2013. We also analyze two observations from Chandra and XMM in the period from 2003 to 2004. In this ten-year period, 1RXS J170849.0-400910 displayed several rotational glitches. Previous studies have claimed variations in the X-ray emission associated with some of the glitches. From our analysis we find no evidence for significant X-ray flux variations and evidence for only low-level spectral variations. We also present an updated timing solution for 1RXS J170849.0-400910, from Rossi X-ray Timing Explorer and Swift observations, which includes a previously unreported glitch at MJD 56019. We discuss the frequency and implications of radiatively quiet glitches in magnetars.