Discovery of PSR J1849-0001, a 38.5 ms Pulsar Powering IGR J18490-0000/HESS J1849-000
ATel #3057; E. V. Gotthelf, J. P. Halpern (Columbia U.), R. Terrier, F. Mattana (CNRS/APC UniversitÃÂ© Paris 7)
on 30 Nov 2010; 14:26 UT
Credential Certification: Jules Halpern (firstname.lastname@example.org)
Subjects: X-ray, Gamma Ray, TeV, Neutron Star, Supernova Remnant, Pulsar
We have detected highly significant X-ray pulsations in a series of pointings
with the Rossi X-ray Timing Explorer Proportional Counter Array at the
putative pulsar/PWN IGR J18490-0000 = HESS J1849-000 = XMMU J184901.6-000117
(Terrier et al.
2008, AIPC, 1085, 312).
The single-peaked pulse profile has a modulation of 4.5% including background.
We identify PSR J1849-0001 with these high-energy counterparts based on the
compatibility of its pulsed 2-20 keV flux with the flux of
XMMU J184901.6-000117, and the morphological properties of the XMM-Newton
source: point-like with faint extended emission. X-ray detections by the
et al. 2008, ApJ, 482, 731) and the Chandra HRC
(Ratti et al.
2010, MNRAS, 408, 1866) also indicate a steady source with no
A preliminary phase-connected ephemeris from 73 ks of RXTE observations
spanning 2010 November 25-29 yields barycentric
P = 0.03851893151(31) s and P-dot = (1.40+/-0.18)E-14 s/s
at epoch MJD 55525.62. Derived pulsar parameters are: spin-down power
9.6E36 erg/s, surface dipole magnetic field strength
7.4E11 G, and characteristic age 44 kyr.
The XMM-Newton spectrum of the pulsar
obtained on 2006 April 3 is fitted with
power-law of photon index Gamma = 1.12+/-0.14,
column density NH = (4.0+/-0.6)E22 cm-2,
and flux F(2-10 keV) = 4.64E-12 erg/cm2/s.
The INTEGRAL/IBIS spectrum is fitted by Gamma = 1.7+/-0.3 and
F(20-100 keV) = (20+/-3) E-12 erg/cm2/s.
These properties resemble those of the dozen other spin-powered pulsars
detected by INTEGRAL
(Mattana et al.
2009, AIPC, 1126, 259;
Renaud et al.
2010, ApJ, 716, 663).
Assuming a location in the Scutum spiral arm tangent region
at a d = 7 kpc, the 0.35-10 TeV flux of HESS J1849-000,
~2.2E-12 erg/cm2/s, is 0.13% of the spin-down luminosity of PSR J1849-0001,
similar to other middle-aged pulsars. The ratio of the PWN's TeV
to keV flux indicates a system that is just transitioning from
synchrotron X-ray to inverse Compton gamma-ray domination.
Observations belonging to our RXTE Cycle 14 program to discover
and time this pulsar are continuing in 2010 December. These will refine
the ephemeris and associated quantities, and will be reported
in a paper currently in preparation.
We thank the RXTE project for making the time available for this
program, and the mission planners for carefully scheduling the observations.