Extremely, deep milliarcsecond radio observations of the high redshift radio source population

SKA将以微Jansky灵敏度对无线电连续天空进行例行调查。我们从迄今为止使用目前最先进的无线电设施（如e-MERLIN/VLA/EVN）进行的最深入的观测中得知，河外的“SKA天空”将由强烈的恒星形成星系和无线电安静的AGN组成。这些源通常位于红移0.5到4之间，通量密度小于100微焦耳，在许多情况下是发光的合并星系，通常有共同进化的恒星形成和吸积活动。利用现有的观测数据获得这种射电源群的特征对于帮助指导SKA关键科学计划的发展至关重要。作为这一进程的一部分，e-MERGE联盟正在通过对GOODS-N（正式名称为HDF-N）场的极深e-MERLIN、VLA和EVN观测相结合，对这一源群进行有史以来最深的高分辨率无线电研究。这些观测将达到亚微Jansky灵敏度，并具有独特的毫角秒分辨率。这种高角度分辨率，提供了长基线干涉测量（EVN和e-MERLIN）允许空间结构的无线电源人口进行反卷积和恒星形成和吸积的贡献被分开。作为这个博士项目期间更广泛的国际努力的一部分，您将致力于分析这些新的e-MERLIN/VLA & EVN观测，以确定microjansky射电源群，并使用观测方法来分离高红移宇宙中吸积和恒星形成的贡献，从而共同进化。特别是，该项目将侧重于使用叠加分析方法探测最微弱（nJy）通量密度下的射电源大小总体。最初，该计划将侧重于GOODS-N领域中观测到的现有数据，然后通过现有的VLA和即将到来的eMERLIN+EVN（+潜在的AVN）观测扩展到COSMOS领域。

The SKA will routinely survey the radio continuum sky at microJansky sensitivities. We know from the deepest observations made to date using the current state-of-the-art radio facilities, such as e-MERLIN/VLA/EVN, that the extragalactic 'SKA-sky' will be dominated by a mixture of intense star-forming galaxies and radio-quiet AGN. These sources are typically situated between redshifts of 0.5 and 4, have flux densities less than 100microJy and in many cases are luminous merging galaxies often hosting co-evolving star-formation and accretion activity. Obtaining a characterisation of this radio source population with existing observations is vital to help guide the development of the key science programmes for the SKA. As part of this process the e-MERGE consortia are in the process of obtaining one of the deepest-ever high resolution radio studies of this source population via a combination of extremely deep e-MERLIN, VLA and EVN observations of the GOODS-N (formally known as HDF-N) field. These observations will reach sub-microJansky sensitivities and uniquely will have milliarcsecond resolving power. This high angular resolution, provided by long baseline interferometry (EVN and e-MERLIN) allow the spatial structure of this radio source population to be deconvolved and the contributions of star-formation and accretion to be separated. As part of a wider international effort during this PhD project you will work to analysis these new e-MERLIN/VLA & EVN observations to characterise the microjansky radio source population and use observational methods to separate the contributions, and hence co-evolution, of accretion and star-formation in the high redshift universe. In particular this project will focus on using stacking analysis methods to probe the radio source size population at the faintest (nJy) flux densities. Initially this programme will focus on data in-hand observed in the GOODS-N field before being extended to the COSMOS filed via exsiting VLA and upcoming eMERLIN+EVN(+ potentially AVN) observations.