Detection of the Binary Millisecond Pulsar J0437--4715 with the Extreme Ultraviolet Explorer (EUVE)

The binary millisecond pulsar J0437--4715 has been detected in emission with the Extreme Ultraviolet Explorer. Direct pointing measurements joined with data from the deep sky survey provide spectral constraints on the source. For a pulsar at a known distance and using our derived spectrum, we derive the total hydrogen column density. We combine this with radio data to obtain independent estimates of N_e and N_H. If we assume a nominal pulsar distance of 140 pc and a thermal spectrum then a source of heating is required to explain the emission from a neutron star with a characteristic age of over a Gyr. Both external and internal heating sources are possible, including accretion from the binary companion or the ISM, polar cap heating, dissipation at the crust/core interface, and exotic nuclear sources. This work has been supported by NAS5-30180.