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ATEL # 989; G.L. Israel and S. Dall'Osso (INAF - AO Roma), S. Campana (INAF - AO Brera), and L. Stella (INAF - AO Roma) on behalf of a larger team
on 6 Feb 2007; 16:40 UT
Password Certification: GianLuca Israel (email@example.com)
Subjects: X-ray, Neutron Stars, Pulsars, Transients
The Swift and Chandra satellites observed the AXP CXO J164710.2-455216 on three epochs between 2007 January 19th and February 2nd (at the beginning of the current target visibility window; total exposure time of about 6ks and 20ks for Swift and Chandra, respectively). By means of these additional archival datasets we were able to refine the previously reported P-Pdot coherent timing solutions (ATel \#929 and \#932). In particular we now detect a highly significant secular spin-down.
According to our analysis the period and period derivative of CXO J164710.2-455216 are: P=10.6106549(2)s and Pdot=9.2(3) e-13\,s/s (1 sigma uncertainties). Both values are consistent with those reported in ATel \#929 and \#932. Therefore, the magnetic field strength of the dipolar component is approximately (assuming a neutron star radius of 10km and a mass of 1.4 solar masses) Bd = 1 e+14\,Gauss, similar to other AXPs.
This coherent timing solution includes also an exponential component required to fit the phases of the Swift and XMM observations taken in the week following the intense burst detected by Swift in September 2006. The parameter of the exponential (glitch-like) component are fully consistent with those determined in our previous analysis (ATel \#932).
We thank the Swift and Chandra directors for approving these additional observations.