Understanding modern radioastronomical observations via advanced numerical simulations

天文观测见证了像OCSCARS和ALMA这样具有前所未有的分辨率、灵敏度和节奏的新型射电望远镜的一波开花。新仪器提供了质量更高的数据，原则上可以比以前更好地约束宇宙中的等离子体过程模型。为了利用这些信息，还需要对天体物理等离子体、波发射和传播过程建立新的、更定量的模型。新一代模型应该描述从能源开始到预测地球上可检测到的信号的过程链。可探测到的无线电波是由微观物理机制引起的。首先必须在大尺度上考虑宏观能源，然后必须描述能量向动力学尺度的转移以及辐射过程--无论是直接的还是需要等离子体不稳定性的过程。我们计划考虑从磁重联开始，大规模释放磁能，到形成可观测的相干无线电波的这一系列过程的所有部分。我们首先关注由于太阳喷发而产生的相干辐射--其中最详细的是可以用来约束理论模型的信息，以及脉冲星发射的相干无线电波(ALMA观测)。完全处理可观察到的无线电信号形成的所有方面需要能力和经验，这超出了一组研究人员的能力。因此，我们计划在我们两个具有互补背景和专业知识的小组之间密切合作开展调查：在德国方面，研究小组SMART继续前国会议员Göttingen小组的工作，目前在柏林理工大学，拥有在动力、混合动力、Vlasov-、与柏林理工学院天文和天体物理中心的天体物理学家以及位于翁德雷约夫的捷克科学院天文研究所的射电天文学小组密切合作的PIC-CODE HPC等离子体以及MHD模拟，该小组已经获得了组装总射电发射率所需的多尺度MHD建模的专业知识及其在无线电/毫米波数据分析方面的重要专业知识，包括开发和使用自己的仪器以及ALMA，将这两个小组的专门知识结合起来，将使我们能够进一步开发和利用所有必要的工具，以更好地了解观测到的太阳喷发和脉冲星的相干射电辐射，利用先进的数值模拟方法了解现代射电天文数据。

Astronomical observations witness a wave of blossom by new radio-telescopes with unprecedented resolution, sensitivity, cadence like OCSCARS and ALMA. The new instruments provide data at a qualitatively higher level which allow, in principle, to constrain models of plasma-processes in the Universe much better than before. To utilize this information also new, more quantitative models of astrophysical plasma-, wave-emission and - propagation processes are needed. The new generation of models should describe the chain of processes starting from the energy sources towards predicting the signals, detectable at Earth. Detectable radio waves are caused by micro-physical mechanisms. The macroscopic energy sources have to be considered first at large scales, then the transfer of energy towards kinetic scales has to be decribed as well as radiation processes – either direct or those requiring plasma instabilities. The emissions have to be derived for the entire emitting volumes and their propagation to the radio antenna has to be taken into account as well as instrument effects.We plan to consider all parts of this chain of processes starting from magnetic reconnection, releasing magnetic energy at large scales, to the formation of observable coherent radio waves. We focus on coherent emissions first due to solar eruptions - for which the most detailed is information is available to constrain theoretical models and on coherent radio waves emitted by pulsars (ALMA observations). The full treatment of all aspects of the formation of the observable radio-signals requires capacities and experience which lead beyond the abilities of one single group of researchers. We therefore plan carry out our investigations in close collaboration between our groups with their complementary background and expertise: on the German side the research group SMART that continues the work of the former TSSSP group of the MPS Göttingen now at the TU Berlin with its long-term experience in kinetic, hybrid-, Vlasov-, PIC-code HPC-plasma- as well as MHD simulations in close collaboration with the astrophysicists of the Center for Astronomy and Astrophysics of the Berlin Institute of Technology (TU) and the radio-astronomy group of the Astronomical Institute of Czech Academy of Sciences at Ondrejov that has acquired expertise in multi-scale MHD modeling necessary for assembling the total radio emissivity and its significant expertise in radio/mm wave data analyses including the development and data use of own instruments as well as of ALMA, hosting one of the nodes of the European Regional ALMA Center.Combining the expertise of the two groups will allow us to further develop and utilize all necessary tools to better understand observed coherent radio emissions of solar eruptions and of pulsars utilizing advanced numerical simulation methods for understanding modernradio-astronomical data.