arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.02454astro-ph.HEastro-ph.GAastro-ph.SR
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外流为附近快速发展的潮汐扰动事件AT2019qiz的光学上升提供动力

An outflow powers the optical rise of the nearby, fast-evolving tidal disruption event AT2019qiz

M. Nicholl, T. Wevers, S. R. Oates, K. D. Alexander, G. Leloudas, F. Onori, A. Jerkstrand, S. Gomez, S. Campana, I. Arcavi, P. Charalampopoulos, M. Gromadzki, N… 展开作者

M. Nicholl, T. Wevers, S. R. Oates, K. D. Alexander, G. Leloudas, F. Onori, A. Jerkstrand, S. Gomez, S. Campana, I. Arcavi, P. Charalampopoulos, M. Gromadzki, N. Ihanec, P. G. Jonker, A. Lawrence, I. Mandel, S. Schulze, P. Short, J. Burke, C. McCully, D. Hiramatsu, D. A. Howell, C. Pellegrino, H. Abbot, J. P. Anderson, E. Berger, P. K. Blanchard, G. Cannizzaro, T. -W. Chen, M. Dennefeld, L. Galbany, S. Gonzalez-Gaitan, G. Hosseinzadeh, C. Inserra, I. Irani, P. Kuin, T. Muller-Bravo, J. Pineda, N. P. Ross, R. Roy, S. J. Smartt, K. W. Smith, B. Tucker, L. Wyrzykowski, D. R. Young

摘要:

在66 Mpc,AT 2019 qiz是迄今为止最接近的光学潮汐破坏事件(TDE),其光度介于大部分人口和iPTF 16 fnl之间。它的接近允许一个非常早期的检测和触发多波长和光谱的后续行动之前,最大的光。主星系的速度色散和TDE光变曲线的拟合表明黑洞质量为$\approx 10^6$ M $_\odot$,破坏了$\approx 1$ M $_\odot$的恒星。综合紫外,光学和X射线数据表明,早期的光发射主要是由外流,与光度演变$L \propto t^2$,一致的光球以恒定的速度($\gtrsim 2000$ km s $^{-1}$),和线形成区域产生最初蓝移的H和He II配置文件与$v=3000-10000$ km s $^{-1}$。最快的光学喷出物接近从无线电探测中推断的速度(在即将发表的K. D.~ Alexander等人),因此,同样的外流可能是造成快速光上升和无线电发射的原因--这是第一次在TDE中观察到这种联系。光变曲线的上升在最大光照之前的$29 \pm 2$天开始,当光球层达到可见光子可以逃逸的半径时达到峰值。光球层然后经历一个突然的转变,首先在恒定半径下冷却,然后在恒定温度下收缩。与此同时,光谱中的蓝移消失,鲍文荧光线(N III)变得突出,这意味着远紫外光子的来源,而X射线光曲线的峰值在$\approx 10^{41}$ erg s $^{-1}$。假设这些X射线是从即时吸积,流出的大小和质量是一致的后处理层需要解释大的光学X射线比在这个和其他光学TDE,可能有利于吸积动力碰撞动力外流模型。

英文摘要:

At 66 Mpc, AT2019qiz is the closest optical tidal disruption event (TDE) to date, with a luminosity intermediate between the bulk of the population and iPTF16fnl. Its proximity allowed a very early detection and triggering of multiwavelength and spectroscopic follow-up well before maximum light. The velocity dispersion of the host galaxy and fits to the TDE light curve indicate a black hole mass $\approx 10^6$ M$_\odot$, disrupting a star of $\approx 1$ M$_\odot$. Comprehensive UV, optical and X-ray data shows that the early optical emission is dominated by an outflow, with a luminosity evolution $L \propto t^2$, consistent with a photosphere expanding at constant velocity ($\gtrsim 2000$ km s$^{-1}$), and a line-forming region producing initially blueshifted H and He II profiles with $v=3000-10000$ km s$^{-1}$. The fastest optical ejecta approach the velocity inferred from radio detections (modelled in a forthcoming companion paper from K.~D.~Alexander et al.), thus the same outflow may be responsible for both the fast optical rise and the radio emission -- the first time this connection has been observed in a TDE. The light curve rise begins $29 \pm 2$ days before maximum light, peaking when the photosphere reaches the radius where optical photons can escape. The photosphere then undergoes a sudden transition, first cooling at constant radius then contracting at constant temperature. At the same time, the blueshifts disappear from the spectrum and Bowen fluorescence lines (N III) become prominent, implying a source of far-UV photons, while the X-ray light curve peaks at $\approx 10^{41}$ erg s$^{-1}$. Assuming that these X-rays are from prompt accretion, the size and mass of the outflow are consistent with the reprocessing layer needed to explain the large optical to X-ray ratio in this and other optical TDEs, possibly favouring accretion-powered over collision-powered outflow models.

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。

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