What powers the radio emission in TDE AT2019dsg: a long-lived jet or the disruption itself?
What powers the radio emission in TDE AT2019dsg: a long-lived jet or the disruption itself?
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TDE AT2019dsg 中无线电发射的动力是什么：是长寿命的喷气机还是干扰本身？
DOI：
10.1093/mnras/stac382
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发表时间：
2022
影响因子：
4.8
通讯作者：
and Julian H. Krolik
中科院分区：
文献类型：
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作者：
Tatsuya Matsumoto;Tsvi Piran;and Julian H. Krolik
通过无线电和X射线观测到潮汐瓦解事件AT2019dsg，并且可能伴随着高能中微子。之前的解释主要集中在中央发动机的持续注入作为无线电发射的能量来源。我们证明连续的能量注入是不必要的；无线电数据可以通过一次等离子体喷射来解释，该等离子体喷射提供了所需的所有能量。为了支持这一论断，我们根据均分模型分析了同步加速器自吸收光谱。与之前的分析类似，我们发现无线电发射区域的能量大约增加∝t0.7，并且该区域的长度尺度以∝t的速度增长。这一事件类似于超新星遗迹的最早阶段：由于喷射的质量远大于冲击的外部质量，其速度保持不变，而冲击气体中的能量随着时间而增长。无线电发射材料从流出中获取能量，而不是从中心物体持续注入能量。虽然不能完全排除来自吸积黑洞的能量注入，但能量注入速率与后退光度有很大不同，并且保持恒定的流出速度需要微调，需要进一步的物理解释。如果中微子关联是真实的，则所需的能量注入远大于无线电发射，这表明检测到的中微子并非来自无线电发射区域。
The tidal disruption event AT2019dsg was observed from radio to X-rays and was possibly accompanied by a high-energy neutrino. Previous interpretations have focused on continued injection by a central engine as the source of energy for radio emission. We show that continuous energy injection is unnecessary; the radio data can be explained by a single ejection of plasma that supplies all the energy needed. To support this assertion, we analyse the synchrotron self-absorbed spectra in terms of the equipartition model. Similar to previous analyses, we find that the energy in the radio-emitting region increases approximately ∝t0.7and the length-scale of this region grows ∝tat a rate. This event resembles the earliest stage of a supernova remnant: because the ejected mass is much greater than the shocked external mass, its velocity remains unchanged, while the energy in shocked gas grows with time. The radio-emitting material gains energy from the outflow, not from continuing energy injection by the central object. Although energy injection from an accreting BH cannot be completely excluded, the energy injection rate is very different from the fallback luminosity, and maintaining constant outflow velocity requires fine-tuning, demanding further physical explanation. If the neutrino association is real, the energy injection needed is much greater than for the radio emission, suggesting that the detected neutrino did not arise from the radio-emitting region.