A broadband X-ray study of the young neutron star PSR B1706-44

The young "Vela"-like neutron star PSR B1706-44 was imaged by both the HRI aboard ROSAT and the solid-state imaging spectrometers and gas imaging spectrometers aboard ASCA during a 6 month period in late 1994 and early 1995. The broadband data set, extending over two decades in energy, allowed a detailed spatial, spectral, and temporal study to be conducted. PSR B1706-44 is found embedded in a compact synchrotron nebula of physical size similar to 0.32 pc and displays the morphology characteristic of the other young neutron stars in the 10(4)-10(5) yr age range. No pulsations at the radio period were detected in either the ROSAT or the ASCA data. The spectrum is well described by a power-law distribution, and the data are consistent with there being no spectral break from the radio through the soft X-ray band. The unpulsed TeV emission that has been observed from PSR B1706-44 can be reconciled with these observations if the TeV emission results from the up-scattering of background IR photons by the population of high-energy particles that produce the soft X-ray photons.