基于DBBC+Mark 5B记录系统的脉冲星观测

Observations of Pulsars with a Record System Combining a DBBC and a Mark 5B

2009年11月,云南天文台射电天文研究团组采用40 m射电望远镜以及基于DBBC(Digital Base Band Conveter)和Mark 5B的VLBI记录系统对PSR J0835-4510和PSRJ0332+5434进行了观测。观测选用S波段右旋圆极化信号,起始频率为2 206.99 MHz,总带宽为32 MHz。对数据进行相干消色散和平均后,得到PSR J0332+5434的单脉冲图像和两颗脉冲星的平均脉冲轮廓。由平均轮廓的展宽随时间的变化关系,对脉冲星的视周期作了一定修正后,得到信噪比更高的平均轮廓图。最后对轮廓的信噪比随时间的变化作了初步分析,由此可了解整个系统在观测时的稳定性。

In November 2009, some observations of the pulsars PSR J0332 ＋ 5434 and PSR J0835 - 4510 were carried out by the radio astronomy group of the YNAO（the Yunnan Observatory）, with a VLBI backend based on a DBBC （Digital Baseband Conveter）and Mark 5B combination. A RCP（Right Circular Polarization） S-band detection range was selected for the observations. The range has a width of 32 MHz and a starting frequency at 2 206.99 MHz. After the de-dispersing and averaging, single pulses of PSR J0332 ＋ 5434 and mean profiles of both pulsars were obtained. We derive mean profiles of higher signal-to-noise ratios （S/N） by improving the periods of the pulses. We further analyze the relation between S/N of a mean profile and integration time, which yields the estimation of the stability of the observation system.