Letter to the Editor

Linking the X-ray timing and spectral properties of the glitching AXP 1RXS J170849-400910 

¹ INAF – Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monte Porzio Catone, Italy e-mail: gianluca@mporzio.astro.it
² CEA Saclay, DSM/DAPNIA/Service d'Astrophysique, 91191 Gif-sur-Yvette, France
³ Mullard Space Science Laboratory University College of London Holmbury St Mary, Dorking, Surrey, RH5 6NT, UK
⁴ SRON – Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands

Received: 3 July 2007
Accepted: 24 October 2007

Abstract

Aims.Previous studies of the X-ray flux and spectral properties of 1RXS J170849-400910 showed a possible correlation with the spin glitches that occurred in 1999 and 2001. However, due to the sparseness of spectral measurements and the paucity of detected glitches, no firm conclusion could be drawn.

Methods.We retrieved and analysed archival Rossi-XTE pointings of 1RXS J170849-400910 covering the time interval between January 2003 and June 2006 and carried out a detailed timing analysis with phase fitting techniques.

Results.We detected two large glitches ( of 1.2 and ) that occurred in January and June 2005. The occurrence times of these glitches are in agreement with the predictions made in our previous studies.
This finding strongly suggests a connection between the flux, spectral and timing properties of 1RXS J170849-400910.