2012ApJ...746....6D

We present extensive spectral and photometric observations of the recycled pulsar/white dwarf binary containing PSR J0437-4715, which we analyzed together with archival X-ray and gamma-ray data, to obtain the complete mid-infrared to gamma-ray spectrum. We first fit each part of the spectrum separately, and then the whole multi-wavelength spectrum. We find that the optical-infrared part of the spectrum is well fit by a cool white dwarf atmosphere model with pure hydrogen composition. The model atmosphere (T_eff= 3950±150 K, log g = 6.98±0.15, R_WD= (1.9±0.2)x10⁹ cm) fits our spectral data remarkably well for the known mass and distance (M = 0.25±0.02 M_☉, d = 156.3±1.3 pc), yielding the white dwarf age (τ_WD= 6.0±0.5 Gyr). In the UV, we find a spectral shape consistent with thermal emission from the bulk of the neutron star surface, with surface temperature between 1.25 x10⁵ and 3.5x10⁵ K. The temperature of the thermal spectrum suggests that some heating mechanism operates throughout the life of the neutron star. The temperature distribution on the neutron star surface is non-uniform. In the X-rays, we confirm the presence of a high-energy tail which is consistent with a continuation of the cutoff power-law component (Γ = 1.56±0.01, E_cut= 1.1±0.2 GeV) that is seen in gamma rays and perhaps even extends to the near-UV.