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We show that a pair of thermal, antipodal hot-spots on the neutron star surface is able to fully account for the pulsars double blackbody spectrum and energy-dependent pulse profile, including the observed 180 degree phase reversal at approximately 1.2 keV. By comparing the observed pulse modulation and phase to the model predictions, we strongly constrain the hot-spot pole (xi) and the line-of-sight (psi) angles with respect to the spin axis. For a nominal radius of R = 12 km and distance D = 2.2 kpc, we find (xi,psi) = (86d,6d), with 1-sigma error ellipse of (2d,1d); this solution is degenerate in the two angles. The best-fit spectral model for this geometry requires that the temperatures of the two emission spots differ by a factor of 2 and their areas by a factor of ~ 20. Including a cosine-beamed pattern for the emitted intensity modifies the result, decreasing the angles to (84d,3d); however this model is not statistically distinguishable from the isotropic emission case. We also present a new upper limit on the period derivative of Pdot < 3.5E-16 (2-sigma), which limits the global dipole magnetic field to B_s < 2.0E11 G, confirming PSR J0821-4300 as an anti-magnetar. We discuss the results in the context of observations and theories of nonuniform surface temperature on isolated NSs of both weak and strong magnetic field. To explain the nonuniform temperature of PSR J0821-4300 may require a crustal field that is much stronger than the external, global dipole field.
RX J0822-4300 is the Central Compact Object associated with the Puppis A supernova remnant. Previous X-ray observations suggested RX J0822-4300 to be a young neutron star with a weak dipole field and a peculiar surface temperature distribution domina
We present an improved proper motion measurement of the central compact object RX J0822-4300, located in the supernova remnant Puppis A. By employing a new data set taken in February 2019 by the High Resolution Camera aboard the Chandra X-ray Observa
The Vela and Puppis A supernova remnants (SNRs) comprise a large emission region of $sim 8^{circ}$ diameter in the soft X-ray sky. The HaloSat CubeSat mission provides the first soft X-ray ($0.4-7$ keV) observation of the entire Vela SNR and Puppis A
Pulsating thermal X-ray emission from millisecond pulsars can be used to obtain constraints on the neutron star equation of state, but to date only five such sources have been identified. Of these five millisecond pulsars, only two have well constrai
Transitional pulsars provide us with a unique laboratory to study the physics of accretion onto a magnetic neutron star. PSR J1023+0038 (J1023) is the best studied of this class. We investigate the X-ray spectral properties of J1023 in the framework