Stellar Populations in Spiral Galaxies

螺旋星系中的恒星群***星系的演化是一个令人兴奋的主题，主要是因为我们越来越有能力建造强大的仪器，在星系年轻得多的时候观察远距离，但也因为我们对它们的内容有了更多的了解。然而，星系组成部分的组合和演化仍然没有得到很好的理解。恒星群是一个星系随时间变化的良好追踪者。因此，这里建议使用它们来深入了解驱动恒星形成和星系演化的不同机制。该研究项目将包括位于蒙特-姆萨甘塔天文台和加拿大-法国-夏威夷望远镜的最新天文仪器SpIOMM和SITELLE，以高空间分辨率同时获得附近星系整个表面上每个区域的可见光谱。在这些数据中看到的发射和吸收线将使用演化恒星群合成模型和辐射转移代码进行分析，以表征星系组成部分的年龄、化学成分和质量。一种分离光谱中重叠的不同种群特征的技术有待改进。要特别注意污染成分光谱指示物的扩散电离气体。这种气体的起源还没有很好地确定，但现在有了这些新仪器，研究起来更容易了。年轻的星暴区域也将利用大量OB星产生的紫外线通量和紫外线成像望远镜（将于2015年发射）的数据进行分析。UVIT将非常有用地将星爆紫外线特性和形态与来自SpIOMM和SITELLE的可见地面数据进行比较。所有这些仪器提供的高空间分辨率对于建立不同成分属性之间的联系将是独一无二的，例如通过星系盘测量化学丰度梯度。为了了解影响恒星形成和星系演化的不同机制，正在设计SITELLE和UVIT巡天，其中包括附近具有不同性质（条形、相互作用、质量）的螺旋星系。这个项目正在准备工具，并为新一代大型望远镜在更大距离上的星系研究设定方向

STELLAR POPULATIONS IN SPIRAL GALAXIES***The evolution of galaxies is an exciting subject, mainly because or our increasing capabilities to build powerful instruments to look at large distances when galaxies were much younger, but also because we understand more about their content. Nevertheless, the assemblage and evolution of galaxy components is still not well understood. Stellar populations are good tracers of the change experienced by a galaxy over time. It is therefore proposed here to use them to gain insights into the different mechanisms that drive star formation and galaxy evolution. This research program will include SpIOMM and SITELLE, new state of the art astronomical instruments at the Observatoire du Mont-Mégantic and Canada-France-Hawaii Telescope, to obtain simultaneously spectra in the visible for every region on the whole surface of a nearby galaxy with a high spatial resolution. Emission and absorption lines seen in these datacubes will be analysed using evolutionary stellar population synthesis models and radiative transfer codes to characterize the age, chemical composition, and mass of the galaxy components. A technique to separate the signatures of the different populations that overlap in a spectrum is to be refined. A special attention is to be given to the diffused ionized gas that is contaminating the component spectral indicators. The origin of this gas is not well established yet, but becomes easier to study now with these new instruments. Young starburst regions will also be analyzed using the ultraviolet flux produced by their numerous OB stars with data from the Ultraviolet Imaging Telescope (to be launched in 2015). UVIT will be extremely useful to compare the starburst ultraviolet properties and morphology with the visible ground-based data from SpIOMM and SITELLE. The high spatial resolution offered by all these instruments will be unique to establish links between the different component properties, for example to measure chemical abundance gradients through the galactic disks. SITELLE and UVIT surveys are being designed which include nearby spiral galaxies with different properties (bar, interactions, mass) in order to understand the different mechanisms that are influencing star formation and galaxy evolution. This program is preparing the tools and setting the orientation for the study of galaxies at larger distances with the new generation of large telescopes to come.**