AAS 197, January 2001
Session 82. Supernova Remnants: Multispectral Observations
Display, Wednesday, January 10, 2001, 9:30am-7:00pm, Exhibit Hall

## [82.01] Chandra X-ray Observation of the SNR Kes~75 and its 700 yr-old pulsar

E.V. Gotthelf, D.J. Helfand (Columbia), R.H. Becker (UC Davis/IITP)

We have observed with the Chandra X-ray Observatory the young Galactic supernova remnant Kes~75, one of the few examples of a shell-type remnant with a central compact radio core. Most recently we have discovered a 700 yr-old X-ray pulsar PSR~J1846-0258, the youngest known pulsar, located to within 12\prime\prime of this core by the ASCA observatory. Timing analysis indicates that PSR~J1846-0258 is being spun down rapidly by torques from a large magnetic dipole of strength ~5.0 \times 1013 Gauss, just above the so-called quantum critical field. Here we present preliminary ACIS imaging-spectroscopy analysis of Kes~75 to locate the pulsar more precisely and confirm PSR~J1846-0258 as a Crab-like pulsar whose period, spin-down rate, and spin-down conversion efficiency, are each an order-of-magnitude greater than the Crab, most likely as a result of its extreme magnetic field. Unlike for the slightly older Crab, the association of a shell-type remnant in Kes~75 with a coeval pulsar provides strong evidence that neutron stars are born in supernovae explosions. Furthermore, the Kes~75 system shows that pulsars may be born with much stronger magnetic fields than previously thought, significantly influencing their early evolution.

This work is supported by NASA LTSA grant NAG5--7935 and a grant from the Chandra Science Center.