RXTE Observation of PSR B0656+14
Abstract
Description
PSR B0656+14 was observed by the {\it Rossi X-ray Timing Explorer (RXTE)} with the proportional counter array (PCA) and the high-energy x-ray timing experiment (HEXTE) for 160 ksec during August 22 -- September 3, 1997. No pulsation was firmly found in the timing analysis, in which the contemporaneous radio ephemeris and various statistical tests were applied for searching evidence of pulsation. A marginal detection of pulsation at a confidence level of 95.5% based on the $H$-test was found with data in the whole HEXTE energy band. In the energy band of 2-10 keV the {\it RXTE} PCA upper limits are about one order of magnitude lower than that from {\it ASCA} GIS data. If the {\it CGRO} EGRET detection of this pulsar is real, considering the common trait that most EGRET-detected pulsars have a cooling spectrum in hard x-ray and gamma ray energy bands, the estimated {\it RXTE} upper limits indicate a deviation (low-energy turn-over) from a cooling spectrum starting from 20 keV or higher. It in turn suggests an outer-magnetospheric synchrotron-radiation origin for high-energy emissions from PSR B0656+14. The {\it RXTE} PCA upper limits also suggest that a reported power-law component based on {\it ASCA} SIS data in 1-10 keV fitted jointly with {\it ROSAT} data, if real, should be mainly unpulsed.
10 pages, LaTeX (aaspp4.sty), figures (eps) included. To appear in ApJ 501 on Jan. 1, 1999
10 pages, LaTeX (aaspp4.sty), figures (eps) included. To appear in ApJ 501 on Jan. 1, 1999