Swift/Chandra refined timing solution for the bursting transient Anomalous X-ray Pulsar CXO J164710.2-455216
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
Credential Certification: GianLuca Israel (gianluca@mporzio.astro.it)
Subjects: X-ray, Neutron Star, Transient, Pulsar
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.
