arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0704.3572astro-ph
收藏

92厘米波段半导体激光器的次脉冲调制特性及其与频率的关系

The subpulse modulation properties of pulsars at 92 cm and the frequency dependence of subpulse modulation

P. Weltevrede, B. W. Stappers, R. T. Edwards

摘要:

利用韦斯特博克综合射电望远镜观测了一个大样本的类星体,以研究它们在21和92厘米观测波长(如果可以实现的话)下的子脉冲调制。在本文中,我们提出了92厘米的数据和比较与已经公布的21厘米的结果。我们用涨落谱分析了191颗92厘米的双星。脉冲星的样本对于任何特定的脉冲星特征都是尽可能无偏的。首次发现了15颗恒星的漂移子脉冲,并证实了21厘米数据中发现的26颗新的漂移子脉冲。我们发现了8个源的零化现象,发现8个双星间歇地发射单脉冲,其脉冲能量与巨脉冲相似。据估计,当观测到足够高的信噪比时,至少有一半的双星具有漂移的子脉冲。漂移的次脉冲机制很可能是发射机制本身的固有特性,尽管对于某些双星来说,它很难或不可能被探测到。漂移子脉冲通常在两个频率下都能发现,尽管在92 cm处检测到漂移子脉冲的机会可能略高。看起来,最年轻的脉冲星具有最无序的子脉冲,并且随着脉冲星年龄的增长,子脉冲变得越来越有组织地成为漂移的子脉冲。与调制指数的相关性被认为是一致的图片中,无线电发射可以被划分在一个漂移的子脉冲信号加上一个准稳定的信号变得,平均而言,在高观测频率更强。在这两个频率的P3的测量值是高度相关的,但没有证据表明与其他脉冲星参数的相关性。

英文摘要:

A large sample of pulsars has been observed to study their subpulse modulation at an observing wavelength (when achievable) of both 21 and 92 cm using the Westerbork Synthesis Radio Telescope. In this paper we present the 92-cm data and a comparison is made with the already published 21-cm results. We analysed 191 pulsars at 92 cm using fluctuation spectra. The sample of pulsars is as unbiased as possible towards any particular pulsar characteristics. For 15 pulsars drifting subpulses are discovered for the first time and 26 of the new drifters found in the 21-cm data are confirmed. We discovered nulling for 8 sources and 8 pulsars are found to intermittently emit single pulses that have pulse energies similar to giant pulses. It is estimated that at least half of the total population of pulsars have drifting subpulses when observations with a high enough signal-to-noise ratio would be available. It could well be that the drifting subpulse mechanism is an intrinsic property of the emission mechanism itself, although for some pulsars it is difficult or impossible to detect. Drifting subpulses are in general found at both frequencies, although the chance of detecting drifting subpulses is possibly slightly higher at 92 cm. It appears that the youngest pulsars have the most disordered subpulses and the subpulses become more and more organized into drifting subpulses as the pulsar ages. The correlations with the modulation indices are argued to be consistent with the picture in which the radio emission can be divided in a drifting subpulse signal plus a quasi-steady signal which becomes, on average, stronger at high observing frequencies. The measured values of P3 at the two frequencies are highly correlated, but there is no evidence for a correlation with other pulsar parameters.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑