Long-term radio and X-ray evolution of the tidal disruption event ASASSN-14li
Long-term radio and X-ray evolution of the tidal disruption event ASASSN-14li
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DOI：
10.1093/mnras/sty077
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发表时间：
2018-01
影响因子：
4.8
通讯作者：
J. Bright;R. Fender;S. Motta;K. Mooley;Y. Perrott;S. Velzen;S. Carey;J. Hickish;N. Razavi-Ghods;D. Titterington;P. Scott;K. Grainge;A. Scaife;T. Cantwell;C. Physics;U. Oxford;Oxford;UK.;A. Group;C. Laboratory;Cambridge;D. Physics;Astronomy;T. J. H. University;Baltimore.;Usa;J. B. C. F. Astrophysics;U. Manchester;Manchester
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文献类型：
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作者：
J. Bright;R. Fender;S. Motta;K. Mooley;Y. Perrott;S. Velzen;S. Carey;J. Hickish;N. Razavi-Ghods;D. Titterington;P. Scott;K. Grainge;A. Scaife;T. Cantwell;C. Physics;U. Oxford;Oxford;UK.;A. Group;C. Laboratory;Cambridge;D. Physics;Astronomy;T. J. H. University;Baltimore.;Usa;J. B. C. F. Astrophysics;U. Manchester;Manchester
我们报道了对潮汐破裂事件候选者ASASSN-14Li的后期射电和X射线观测，覆盖了衰减期的前1000天。在最初的200天里，无线电和X射线辐射会同时减弱。X射线波长处的指数衰减能较好地描述这一位相，而射电辐射则可用指数衰减或潮汐破坏事件的典型衰减来描述。这一时期射电辐射与X射线辐射之间的相关关系可用L{R}与L{X}^{1.9\pm0.2}$进行拟合。400天后，射电辐射达到244美元/平方千米的平稳水平，至少在接下来的600天内保持不变，而X射线辐射继续呈指数衰减。这种稳定的射电发射水平很可能是由于历史射电观测所暗示的弱活动星系核活动的残馀射电叶所致。我们注意到，虽然大多数现有的模型都是基于从中心黑洞分离出来的抛射物的演化，但下降阶段的射电-X射线关联也与与辐射有效的吸积流耦合的核喷流相一致。
We report on late time radio and X-ray observations of the tidal disruption event candidate ASASSN-14li, covering the first 1000 days of the decay phase. For the first $\sim200$ days the radio and X-ray emission fade in concert. This phase is better fit by an exponential decay at X-ray wavelengths, while the radio emission is well described by either an exponential or the canonical $t^{-5/3}$ decay assumed for tidal disruption events. The correlation between radio and X-ray emission during this period can be fit as $L_{R}\propto L_{X}^{1.9\pm0.2}$. After 400 days the radio emission at $15.5\,\textrm{GHz}$ has reached a plateau level of $244\pm8\,\mu\textrm{Jy}$ which it maintains for at least the next 600 days, while the X-ray emission continues to fade exponentially. This steady level of radio emission is likely due to relic radio lobes from the weak AGN-like activity implied by historical radio observations. We note that while most existing models are based upon the evolution of ejecta which are decoupled from the central black hole, the radio : X-ray correlation during the declining phase is also consistent with core jet emission coupled to a radiatively efficient accretion flow.