SINGLE-PULSE RADIO OBSERVATIONS OF THE GALACTIC CENTER MAGNETAR PSR J1745–2900
SINGLE-PULSE RADIO OBSERVATIONS OF THE GALACTIC CENTER MAGNETAR PSR J1745–2900
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DOI：
10.1088/0004-637x/814/1/5
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发表时间：
2015-10
期刊：
影响因子：
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通讯作者：
Zhen Yan;Zhi-qiang Shen;Xin-ji Wu;R. Manchester;P. Weltevrede;Yajun Wu;R. Zhao;Jian-ping Yuan
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文献类型：
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作者：
Zhen Yan;Zhi-qiang Shen;Xin-ji Wu;R. Manchester;P. Weltevrede;Yajun Wu;R. Zhao;Jian-ping Yuan
在本文中，我们报告了2014年6月至10月期间六个时期对银河系中心磁星PSR J1745-2900的射电观测。这些观测是使用新的上海天马射电望远镜进行的，频率为8.6 GHz。PSR J1745-2900的通量密度和综合剖面都显示出历元间的剧烈变化，表明该脉冲星处于“不稳定”阶段。在MJD 56836上，这颗磁星的通量密度约为8.7 mJy，比发现时报道的大10倍，可以进行单脉冲分析。辐射主要是窄的“尖”脉冲，在峰值通量密度中遵循对数正态分布。从1913个脉冲中，我们检测到53个脉冲的峰值通量密度是综合剖面的10倍。它们集中在脉冲相位的综合剖面的峰值处。这些亮脉冲在50%水平的脉冲宽度在0。°2和0。°9，比集成剖面（~ 12°）窄得多。观测到的脉冲宽度可能受到星际散射的限制。这些脉冲的宽度和峰值通量密度之间没有明显的相关性，也没有发现亚脉冲漂移的证据。在其他5个观测期也检测到相对较强的尖脉冲，显示出与MJD 56836相同的特性。这些强尖脉冲不能归类为“巨型”脉冲，但与正常脉冲发射更密切相关。
In this paper, we report radio observations of the Galactic Center magnetar PSR J1745–2900 at six epochs between 2014 June and October. These observations were carried out using the new Shanghai Tian Ma Radio Telescope at a frequency of 8.6 GHz. Both the flux density and integrated profile of PSR J1745–2900 show dramatic changes from epoch to epoch, showing that the pulsar was in its “erratic” phase. On MJD 56836, the flux density of this magnetar was about 8.7 mJy, which was 10 times larger than that reported at the time of discovery, enabling a single-pulse analysis. The emission is dominated by narrow “spiky” pulses that follow a log-normal distribution in peak flux density. From 1913 pulses, we detected 53 pulses whose peak flux densities are 10 times greater than that of the integrated profile. They are concentrated in pulse phase at the peaks of the integrated profile. The pulse widths at the 50% level of these bright pulses were between 0.°2 and 0.°9, much narrower than that of the integrated profile (∼12°). The observed pulse widths may be limited by interstellar scattering. No clear correlation was found between the widths and peak flux density of these pulses and no evidence was found for subpulse drifting. Relatively strong spiky pulses are also detected in the other five epochs of observation, showing the same properties as those detected in MJD 56836. These strong spiky pulses cannot be classified as “giant” pulses but are more closely related to normal pulse emission.