Publication Date:
2019-06-28
Description:
This grant, titled 'X-Ray Emission from Two Nearby Millisecond Pulsars,' included ROSAT observations of the nearby pulsars PSR J2322+20 and PSR J2019+24. Neither was detected, although the observations were among the most sensitive ever made towards millisecond pulsars, reaching 1.5 x 10(exp 29) and 2.7 x 10(exp 29) erg s(exp -1) (0.1-2.4 keV), respectively. This is about, or slightly below, the predicted level of emission from the Seward and Wang empirical prediction, based on an extrapolation from slower pulsars. To understand the significance of this result, we have compared these limits with observations of four other millisecond pulsars, taken from the ROSAT archives. Except for the case of PSR B1821-21, where we identified a possible x-ray counterpart, only upper limits on x-ray flux were obtained. From these results, we conclude that x-ray emission beaming does not follow the same dependence on pulsar period as that of radio emission: while millisecond pulsars have beaming fractions near unity in the radio, x-ray emission is observed only for favorable viewing geometries.
Keywords:
ASTRONOMY
Type:
NASA-CR-196142
,
NAS 1.26:196142
Format:
application/pdf
