  We report on the quiescent X-ray properties of the recently discovered
transiently accreting 11 Hz X-ray pulsar in the globular cluster Terzan 5.
Using two archival Chandra observations, we demonstrate that the quiescent
spectrum of this neutron star low-mass X-ray binary is soft and can be fit to a
neutron star atmosphere model with a temperature of kT^inf~73 eV. A powerlaw
spectral component is not required by the data and contributes at most ~20% to
the total unabsorbed 0.5-10 keV flux of ~9E-14 erg/cm2/s. Such a soft quiescent
spectrum is unusual for neutron stars with relatively high inferred magnetic
fields and casts a different light on the interpretation of the hard spectral
component, which is often attributed to magnetic field effects. For a distance
of 5.5 kpc, the estimated quiescent thermal bolometric luminosity is ~6E32
erg/s. If the thermal emission is interpreted as cooling of the neutron star,
the observed luminosity requires that the system is quiescent for at least ~100
years. Alternatively, enhanced neutrino emissions can cool the neutron star to
the observed quiescent luminosity.

High Energy Astrophysical Phenomena