The Planetary Nebulae of Spiral Galaxies

这一研究项目旨在揭示星系形成的后期阶段，特别是螺旋星系中扩展的恒星和暗物质晕的形成，据认为这主要是由星系合并和吸积事件造成的。由于那里的动力学时间尺度很长（几个千兆年），吸积事件在星系的相空间中留下了印记。然而，测量我们本星系群之外的单个恒星的属性仍然非常困难，因此使用行星状星云（PNe）代替。这些离散的示踪剂充当灯塔，其明亮的发射线可检测/测量到数十兆秒差距的距离。到目前为止，大多数PN研究都集中在椭圆星系和透镜星系上，但这个项目将打破这一障碍，瞄准螺旋星系。事实上，新一代的宽视场积分场摄谱仪使我们能够区分PNE和闯入者（如超新星遗迹和恒星形成区），并反过来首次绘制这些星系晕的组成和运动学。特别是，该项目将把PN属性与通常的恒星种群属性联系起来（年龄和金属丰度）从综合光测量，从而限制星系的运动学和发光+暗物质的内容一直从他们的中心到他们的晕。学生将信号项目的一部分（恒星形成、电离气体和星云丰度遗留调查），这是一个利用加拿大-法国夏威夷望远镜革命性的成像傅里叶变换摄谱仪SITELLE的实时方案。SIGNALS利用数十个观测夜晚详细研究了附近40多个螺旋星系，以及其前所未有的视野（比竞争对手好100倍以上！）可以同时探测和探测整个星系的PNe。大多数数据已经掌握，大多数分析工具也是如此，因此学生将直接进入PNE的分析和数据的科学解释。该项目特别适合对星系（动力学，形成和演化）和观测天文学感兴趣的学生。

This research project aims to unravel the late stages of the formation of galaxies, in particular the build-up of the extended stellar and dark matter halos of spiral galaxies, thought to be dominated by galaxy mergers and accretion events. As the dynamical timescales there are long (several gigayears), the accretion events are imprinted in the galaxies' phase-spaces. Measuring the properties f individual stars beyond our Local Group of galaxies remains extremely difficult, however, so planetary nebulae (PNe) are used instead. These discrete tracers act as lighthouses, their bright emission lines being detectable/measurable to distances of several tens of megaparsecs. The majority of PN studies to date have focused on elliptical and lenticular galaxies, but this project will break this barrier and target spiral galaxies. Indeed, a new generation of wide-field integral-field spectrographs enables us to discriminate PNe from interlopers (such as supernova remnants and star-formation regions), and in turn map for the first time the composition and kinematics of these galaxies' halos robustly. In particular, the project will relate the PN properties to the usual stellar population properties (age and metallicity) measured from integrated light, and thus constrain the galaxies' kinematics and luminous+dark matter contents all the way from their centres to their halos.The student will be part of the SIGNALS project (star-formation, ionised gas and nebular abundances legacy survey), a guaranteed-time programme using the revolutionary imaging Fourier transform spectrograph SITELLE at the Canada-France Hawaii Telescope. SIGNALS exploits several tens of observing nights to study in detail over 40 nearby spiral galaxies, and its unprecedented field of view (over 100 times better than its competitors!) allows to simultaneously detect and characterise the PNe across the galaxies. Most of the data are already in hand, as are most of the analysis tools, so the student will dive right into the analysis of the PNe and the scientific interpretation of the data. The project is particularly suited to a student with an interest in galaxies (dynamics, formation and evolution) and observational astronomy.