A Comprehensive Study of Nearby Galaxy Mergers with a Massive Integral-Field Spectroscopic Survey

自20世纪70年代以来，碰撞和合并在星系演化中所起的重要作用已经得到了认识。以前对碰撞/合并星系的光谱研究，虽然证实了几个基本的预测（例如，核恒星形成和/或黑洞吸积的增加），但通常只以很大程度上不均匀的方式探索了它们最明亮的内部区域。这项研究将使用一个宽视场积分场光谱仪（IFS）来测量大约1300个局部碰撞/合并星系的结构、运动学、活动（恒星形成和/或黑洞吸积）和化学富集。对近一万个质量相似的孤立星系进行相同的观测，将为揭示碰撞和合并的全部影响提供必要的“控制”。该项目将支持一名研究生和两名本科生，后者的任务是为机器人学生望远镜建造和实施IFS。这项研究将首先确定1,300个相互作用的星系（早期到后期合并），这些星系来自于APO (MaNGA) IFS对10,000个z 0.04星系进行的更大的SDSS-IV邻近星系测绘，后者比以前的此类调查增加了10倍。然后，该团队将从IFS数据中提取精确的直线和连续测量值，以确定每个系统的结构和运动学，大质量恒星形成和气相金属丰度的面积分布，以及描述任何核活动（星爆和/或黑洞吸积）。从MaNGA调查中获得的质量匹配的更大的孤立星系样本将以相同的方式进行分析，以作为“控制”，帮助将合并从随机活动中分离出来。从这些数据中，研究小组将得出依赖质量的合并率，诱导恒星形成和化学富集的空间范围，以及黑洞吸积与合并状态的占空比和相关性的估计。这个项目触及了Astro2010年十年调查的两个科学“前沿”问题，即重子是如何进出星系的（以及它们在那里做什么），以及黑洞是如何生长并影响周围环境的？这项工作将支持一名研究生和两名本科生。后者将为亚利桑那州0.5米爱荷华机器人望远镜的中分辨率IFS建立和编写控制/采集/缩减软件。这台仪器将为爱荷华大学的主动学习光谱天文学实验室做出贡献。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The important role played by collisions and mergers in galaxy evolution has been appreciated since the 1970's. Previous spectroscopic studies of colliding/merging galaxies, while confirming several basic predictions (e.g., elevated nuclear star formation and/or black hole accretion), generally explored only their brighter inner-most regions in a largely non-uniform manner. This research will use a wide-field integral field spectrometer (IFS) to measure the structure, kinematics, activity (star formation and/or black hole accretion), and chemical enrichment for approximately 1,300 local colliding/merging galaxies over their full visible extents. Identical observations of nearly 10,000 isolated galaxies of like masses will provide an essential "control" to reveal the full effects of collisions and mergers. This project will support one graduate and two undergraduate students, the latter tasked with building and implementing an IFS for a robotic student telescope.This research will first identify 1,300 interacting galaxies (early to late-stage mergers) from the larger SDSS-IV Mapping Nearby Galaxies at APO (MaNGA) IFS survey of 10,000 z 0.04 galaxies, the latter representing a 10-fold increase over previous such surveys. The team will then extract precise line and continuum measurements from the IFS data to determine each system’s structure and kinematics, the areal distribution of massive star formation and gas phase metallicity, as well as characterizing any nuclear activity (starburst and/or black hole accretion). A much larger sample of isolated galaxies from the MaNGA survey that are matched in mass will be analyzed in an identical manner to serve as a “control” to help isolate merger-induced from stochastic activity. From these data the team will derive estimates of the mass-dependent merger rates, the spatial extent of induced star formation and chemical enrichment, and the duty cycle and correlation of black hole accretion with merger state. This project touches on two science “frontier” questions from the Astro2010 Decadal Survey, namely, how do baryons cycle in and out of galaxies (and what do they do while they are there), and how do black holes grow and influence their surroundings? This work will support one graduate and two undergraduate students. The latter will build and write control/acquisition/reduction software for a medium-resolution IFS for the 0.5-m Iowa Robotic Telescope in Arizona. This instrument will contribute to active-learning spectroscopic astronomy labs at the University of Iowa.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.