Relic jet activity in 'Hanny's Voorwerp' revealed by the LOFAR two metre sky survey
Relic jet activity in 'Hanny's Voorwerp' revealed by the LOFAR two metre sky survey
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LOFAR 两米天空调查揭示了“Hannys Voorwerp”中的遗迹喷气机活动
DOI：
10.1093/mnras/stac1568
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发表时间：
2022
影响因子：
4.8
通讯作者：
Smith D
中科院分区：
文献类型：
--
作者：
Smith D
我们报告了从 LOFAR 两米巡天 (LoTSS) 第二次数据发布中获取的“Hanny’s Voorwerp”（以下简称 HV）的新观测结果。 HV 是星系 IC2497 周围的一个高度电离区域，由星系动物园项目首次发现。新的 150 MHz 观测是在现有多频无线电数据和哈勃太空望远镜档案窄带成像的背景下考虑的，以 [O iii] 发射线为中心。 LoTSS 数据的综合灵敏度和空间分辨率（远远超过以前在无线电频率上可获得的数据）揭示了 IC2497 核发出的大规模扩展发射的明确证据。无线电射流似乎在中性气体晕中打出了一个洞，该区域与高压位于同一区域。新的 150 MHz 数据以及新处理的 1.64 GHz eVLA 档案数据表明，扩展发射具有陡峭的频谱，意味着年龄 > 108 年。为扩展的 150MHz 结构提供能量的射流肯定早在最近的研究报告中报告的 X 射线光度变化之前就已经“关闭”了。在这张图片中，喷流活动和辐射效率高的活跃星系核的影响相结合，导致了 HV 的异常出现。
We report new observations of ‘Hanny’s Voorwerp’ (hereafter HV) taken from the second data release of the LOFAR Two-metre Sky Survey (LoTSS). HV is a highly-ionized region in the environs of the galaxy IC2497, first discovered by the Galaxy Zoo project. The new 150 MHz observations are considered in the context of existing multi frequency radio data and archival narrow-band imaging from theHubble Space Telescope, centred on the[O iii]emission line. The combined sensitivity and spatial resolution of the LoTSS data – which far exceed what was previously available at radio frequencies – reveal clear evidence for large-scale extended emission emanating from the nucleus of IC2497. The radio jet appears to have punched a hole in the neutral gas halo, in a region co-located with HV. The new 150 MHz data, alongside newly-processed archival 1.64 GHz eVLA data, reveal that the extended emission has a steep spectrum, implying an age >108yr. The jet supplying the extended 150 MHz structure must have ‘turned off’ long before the change in X-ray luminosity reported in recent works. In this picture, a combination of jet activity and the influence of the radiatively efficient active galactic nucleus are responsible for the unusual appearance of HV.