The Morphology of Dust-Obscured Starbursts: the e-MERLIN SuperCLASS Legacy Survey

星系——由数千亿颗受引力约束的恒星组成的集合——是我们宇宙进化的基本组成部分。我们自己的银河系在今天的宇宙中被认为是“正常的”，绵延10万光年，以每年1-2个新太阳的速度形成恒星。但是，当我们进一步观察宇宙时，似乎遥远的过去（100亿年前）的星系是截然不同的。每年产生100到2000颗恒星的极端“星暴”星系更为典型，当时形成的大多数恒星都来自这样的星暴。获奖团队正试图确定为什么这些星系在宇宙历史上如此重要，为什么它们如此极端，例如，它们是否是由两个较小星系的灾难性碰撞引起的，或者在宇宙年轻得多的时候，气体（恒星形成所需的燃料）是否更密集、更有效。这些极端的恒星爆发也被尘埃严重遮蔽，使它们很难在可见光下被我们的眼睛看到。来自e-MERLIN望远镜的尖端无线电波长数据将用于穿透尘埃，并确定宇宙中最极端的恒星爆发星系的动力机制。该项目将通过参与德克萨斯大学奥斯汀分校的TAURUS项目来支持保留代表性不足的学生从事天体物理学研究，该项目要求本科生在夏季花九周的时间进行研究项目。获奖者将积极参与和支持像TAURUS这样的社区中代表性不足的学生。利用来自e-MERLIN的高分辨率（0. 1）深（4 uJy）无线电1.4 GHz连续数据集，覆盖SuperCLASS领域的1.77°^2，获奖者将在z~3的统计大样本（少数x 100）中评估高度模糊的无线电星系的进化起源。目标是回答以下问题：(1)尘埃星暴中的高sfr主要是由星系相互作用驱动的吗？(2)在被遮挡的星暴中，来自活动星系核（AGN）的反馈是否起到抑制恒星形成的作用？或者在有或没有无线电发光AGN的恒星爆发中，恒星形成没有明显的区别（以及AGN亮度的依赖是什么）？(3)星系的恒星形成表面密度告诉我们恒星形成的强度和相对的遮蔽几何（与光学成像相比）？(4)能否通过分析星系的射电同步加速器斜率和射电形态来了解神秘的远红外/射电相关性的物理起源？通过对e-MERLIN SuperCLASS数据产品的直接形态分析来回答这些问题，将对星系演化研究产生重大影响。

Galaxies -- collections of hundreds of billions of stars all bound by gravity -- are a fundamental building block in the evolution of our Universe. Our own Milky Way galaxy is regarded as 'normal' in the Universe today, stretching 100,000 light years across and forming stars at a rate of 1-2 new suns per year. But, as we look farther out into the Universe, it seems that galaxies in the distant past (10 billion years ago) were dramatically different. Extreme "starbursting" galaxies that produced 100 to 2,000 stars per year were much more typical, and most stars formed at that time came from such starbursts. The awarded team is trying to determine why these galaxies were so important in the Universe's history and why they are so extreme, for example whether or not they are caused by the catastrophic collision of two smaller galaxies, or whether the gas (the fuel needed to power star formation) was more dense and efficient when the Universe was much younger. These extreme starbursts are also heavily obscured by dust, making them hard to see in optical light visible to our eyes. Cutting edge radio-wavelength data from the e-MERLIN telescope will be used to peer through the dust and determine the powering mechanism for the Universe's most extreme starbursting galaxies. This project will support the retention of under-represented students in astrophysics research through participation in the TAURUS program at UT Austin, where undergraduate students spend nine weeks of the summer on a research project. The awardee will be proactive in engaging and supporting under-represented students in communities like TAURUS.With a unique data set of high-resolution (0."1) deep (4 uJy) radio 1.4 GHz continuum data from e-MERLIN covering 1.77 deg^2 in the SuperCLASS field, the awardees will assess the evolutionary origins of highly-obscured radio galaxies in a statistically large sample (few x 100) out to z~3. The objectives are to answer the following questions: (1) Are the high-SFRs in dusty starbursts primarily driven by galaxy interactions or not? (2) Does feedback from Active Galactic Nuclei (AGN) in obscured starbursts play a role in suppressing star-formation? Or is there no discernible difference in star formation seen in starbursts with or without radio-luminous AGN (and what is the dependence on the AGN luminosity)? (3) What do galaxies' star-formation surface densities tell us about the intensity of star formation and relative obscuration geometries (when compared to optical imaging)? (4) Can one learn about the physical origins of the mysterious far-infrared/radio correlation by analyzing galaxies' radio synchrotron slope and radio morphologies? Answering these questions through direct morphological analysis of the e-MERLIN SuperCLASS data products will have significant impact on galaxy evolution studies.