PROPER MOTION AND TIMING OF TWO UNUSUAL PULSARS: CALVERA AND 1E 1207.4-5209

Using pairs of images from the Chandra High Resolution Camera we examine the proper motion of the central compact object (CCO) 1E 1207.4-5209 in the supernova remnant (SNR) PKS 1209-51/52, and the unusual pulsar Calvera that is possibly a CCO descendant. For 1E 1207.4-5209, an insignificant proper motion of mu = 15 +/- 7 mas yr(-1) is measured, corresponding to a corrected tangential velocity of v(perpendicular to,c) < 180 km s(-1) at the distance of 2 kpc. This proves that the previously noted large offset of the pulsar from the apparent geometric center of the SNR is not due to high proper motion; evidently the symmetry of the remnant does not indicate its center of expansion. Calvera has a marginally significant proper motion of mu = 69 +/- 26 mas yr(-1), corresponding to v(perpendicular to,c) = 86 +/- 33 km s(-1) for a hypothetical distance of 0.3 kpc. Notably, its vector is away from the Galactic plane, although its high Galactic latitude of b = + 37 degrees may be more a consequence of its proximity than its velocity. We also provide updated timing solutions for each pulsar. Spanning 14.5 years, the ephemeris of 1E 1207.4-5209 has a small and steady frequency derivative that, because of the negligible proper motion, requires no kinematic correction. The derived surface dipole magnetic field strength of 1E 1207.4-5209 thus remains B-s = 9.8 x 10(10) G. Calvera has B-s = 4.4 x 10(11) G, intermediate between those of ordinary young pulsars and CCOs, suggesting that it may be on a trajectory of field growth that could account for the absence of descendants in the neighborhood of CCOs in the P-P diagram.