UV-Optical Observations of Pulsars with post-COSTAR HST
Session 78 -- Pulsars and Neutron Stars
Display presentation, Wednesday, 11, 1995, 9:20am - 6:30pm

## [78.01] UV-Optical Observations of Pulsars with post-COSTAR HST

G. S. Stringfellow, G. G. Pavlov, \& F. A. C\'ordova (The Pennsylvania State University)

We have carried out post-COSTAR HST observations with the FOC/96 to search for UV and optical emission from 3 nearby pulsars (PSR 0656+14, PSR 0950+08, and PSR 1929+10) spanning a range in age between $1 \times 10^5 - 2 \times 10^7$ years. All three pulsars were observed with the F130LP filter, and for PSR 1929+10 observations were also obtained for the F342W (U-band) and F430W (B-band) filters. Probable candidates have been detected and count rates determined. The count rates exceed by several orders of magnitude those expected from thermal radiation emitted at the surface of the neutron star, as estimated from ROSAT observations. This radiation must therefore be of a non-thermal origin, and its intensity greatly exceeds predictions of existing phenomenological models. Non-thermal radiation appears to be a more common property of older pulsars than heretofore believed.