Spectral and Timing Analysis of PSR 0656+14: The Nature of its Hard Tail''
Session 8 -- Pulsars
Display presentation, Monday, 30, 1994, 9:20-6:30

## [8.01] Spectral and Timing Analysis of PSR 0656+14: The Nature of its Hard Tail''

Christopher Greiveldinger, Craig Markwardt, Hakk\i\ \"Ogelman, Samar Safi-Harb (University of Wisconsin--Madison), John P. Finley (Purdue University)

Pulsar PSR 0656+14 has a period of 385 ms and a dynamical age of $1.1\times 10^5$ years. The pulsar's rotational energy loss rate is $3.8\times 10^{34}$ erg s$^{-1}$. Two observations of PSR 0656+14 have been done with the ROSAT PSPC. The data from the second, 12 ksec, ROSAT observation yield spectral fits that require two component models. A soft blackbody component (T$\sim8\times 10^5$ K) plus a harder, lower flux component best fits the spectrum. The harder component can be fit by a blackbody (T$\sim2\times 10^6$ K) or a powerlaw ($\alpha=2.7$). The pulse shape, like PSR 1055-52 and Geminga, is observed to be energy dependent. Both the pulse arrival phase and pulsed fraction exhibit variations with energy. The total pulsed fraction is $\sim10\%$. A comparison between radio and X-ray pulse arrival phases will also be presented.