SIGNALS and SITELLE: Massive stars and HII regions in nearby galaxies with imaging Fourier transform spectroscopy

为了响应CFHT最近的大型计划（2018 B-2022 A学期），我共同领导的一个国际团队提交了一份提案，利用其成像傅里叶变换光谱仪SITELLE的独特功能对附近星系中的恒星形成区域进行详细调查。SIGNALS，星星形成，电离气体和星云丰度遗产调查与SITELLE，将基于体积有限的样本的本地扩展星系（D = 10 Mpc），正在积极形成大质量恒星。SIGNALS在未来4年内获得了50个CFHT夜晚的时间，将提供有史以来最大，最完整，最均匀的光谱和空间分辨河外HII区域数据库。这将使我们能够研究小尺度的星云物理学和许多其他与星系中大质量星星形成有关的现象，平均空间分辨率为20 pc。我们的样本包括39个螺旋星系和不规则星系。HII区域呈现出各种各样的特征：形态（从致密到扩展的壳层），质量（低光度区域没有很好的采样），金属丰度（稀有金属贫乏区域研究较少）或年龄（年轻恒星种群的多样性）。它们可能位于不同的星系生态系统中，并与其他电离源（如冲击和AGN）共存。有限体积的样本将提供一个统计上可靠的实验室，有超过50 000个解决的HII区域。通过研究空间分辨的单个HII区域的光谱及其大质量星星含量，SIGNALS旨在了解不同的局部环境（附近恒星的质量和年龄，气体密度和化学成分，动力学结构等）。影响星星的形成过程。我们调查的遗产将反映天体物理学的许多主题，从恒星到非常遥远的星系。我们的主要近期目标是：1）量化的星星形成过程中的周围环境的影响，2）链接的反馈过程的小规模的化学富集和动力学周围的恒星形成区域，和3）测量的变化，解决星星的形成率相对于用于高红移星系的指标。作为SITELLE的PI和SIGNALS的五个共同PI之一，我打算在未来五年内将我的大部分研究时间投入到这个大型项目中。在仪器方面，我将在数据减少和质量评估、软件开发和观测战略方面发挥主导作用，这些都可能在调查过程中发展。在天文学方面，我将借此机会回到我发展成像FTS技术的主要动机，即研究大质量恒星（及其核心坍缩超新星后代）对其周围环境的运动学和化学富集的影响。

In response to CFHT's recent Call for Large Programs (2018B - 2022A semesters), an internatioal team I co-lead submitted a proposal to make use of its Imaging Fourier Transform Spectrometer SITELLE's unique capabilities to conduct a detailed survey of star-forming regions in nearby galaxies. SIGNALS, the Star formation, Ionized Gas, and Nebular Abundances Legacy Survey with SITELLE, will be based on a volume-limited sample of local extended galaxies (D = 10 Mpc) that are actively forming massive stars. SIGNALS, which has been awarded 50 nights of CFHT time over the next 4 years, will provide the largest, most complete, and homogeneous database of spectroscopically and spatially resolved extragalactic HII regions ever assembled. This will enable us to study small-scale nebular physics and many other phenomena linked to massive star formation in galaxies at a mean spatial resolution of ~20 pc. As is, our sample includes 39 spiral and irregular galaxies. HII regions present a wide variety of characteristics: morphology (from compact to extended shell), mass (where the low luminosity regime is not very well sampled), metallicity (where the rare metal-poor regions have been less studied), or age (following the diversity of their young stellar populations). They may be located in different galactic ecosystems and coexist with other sources of ionization (like shocks and AGN). The volume-limited sample will provide a statistically reliable laboratory, with over 50 000 resolved HII regions. By studying the spectra of spatially-resolved individual HII regions and their massive star content, SIGNALS aims at understanding how diverse local environments (nearby stellar population mass and age, gas density and chemical composition, dynamical structures, etc.) affect the star formation process. The legacy of our survey will reflect on many topics in astrophysics, from stars to very distant galaxies. Our primary immediate goals are to : 1) Quantify the impact of the near surrounding environment on the star formation process, 2) Link the feedback processes to the small-scale chemical enrichment and dynamics around star-forming regions, and 3) Measure variations of the resolved star formation rate with respect to indicators used for high-redshift galaxies. As PI of SITELLE and one of the five co-PIs of SIGNALS, I intend to devote most of my research time during the next five years to this Large Program. On the instrument side, I will play a leading role in the data reduction and quality assessment, software development and observational strategy, which will all likely evolve over the course of the survey. On the astronomical side, I will take this opportunity to come back to my main motivations behind the development of the imaging FTS technology, namely to study the influence of massive stars (and their core-collapse supernova descendants) on the kinematics and chemical enrichment of their immediate surroundings.