射电天文研究室知识库

Using the archival data from the Rossi X-ray Timing Explorer, we study the evolution of the Crab pulsar's X-ray profile in a time span of 11 years. The X-ray profiles, as characterized by a few parameters, changed slightly, but with high statistical significance in these years: the separation of the two peaks increased with a rate of 0 degrees.88 +/- 0 degrees.20 per century, the flux ratio of the second pulse to the first pulse decreased by (3.64 +/- 0.86) x 10(-2) per century, and the pulse widths of the two pulses represented by their full widths at half maxima decreased by 1 degrees.44 +/- 0 degrees.15 and 1 degrees.09 +/- 0 degrees.73 per century, respectively. The evolutionary trends of the X-ray profile are similar to that observed in radio, but with quantitative differences. Finally, we briefly discuss the constraints of these X-ray properties on the geometry of the emission region of this pulsar.