The Scaling Relations of Galaxies in the Infrared

利用新的阿塔卡马大型毫米-亚毫米阵列（阿尔马）设施和下一代詹姆斯·韦伯太空望远镜（JWST）进行观测，不久将能够测量星星的形成速率和高红移星系中所含气体的总可用质量，为研究星系在宇宙时间内的生长提供关键信息。 这两个测量是使用星系光谱的不同区域进行的。 这项工作将确定这些数字是如何联系在一起的，以及是否存在有意义的因果联系。 这对于理解这类研究如何可靠地获得所观察星系的物理参数至关重要。 该项目有一个综合的教育组成部分：（1）为来自周边地区的本科生提供暑期研究机会，使他们接触尖端研究;以及（2）当地中小学教师的研究经验，帮助他们与马萨诸塞州制定的新的“内容驱动”测试标准保持一致，阿尔马和JWST之间的协同作用将返回星系的星星形成率（SFR）和气体质量（M_gas），在高红移的光度和物理参数的全范围内，从而揭示了星星形成的效率和星系的生长作为宇宙时间的函数。 通常，SFR是从尘埃的红外光谱能量分布（IR SED）的“蓝”侧导出的，而M_gas是从IR SED的“红”侧导出的。然而，“蓝色”和“红色”之间的二分法是人为的，红外颜色和单色光度显示彼此相关。 如果存在潜在的协方差，则它们对于使用IR SED来导出物理参数可能是有帮助的，也可能是有害的。 本专题将确定这些协方差，包括它们的强度，并确定它们在本质上是物理的（因果相关性）还是微不足道的（例如一些共同的原因）。 应用于阿尔马和其他档案的贝叶斯推理方法将揭示和研究协方差，以（1）研究邻近星系样本中中红外和远红外/毫米颜色之间的相关性;（2）建立尘埃排放的物理模型在何种假设下解释了观测到的颜色-颜色相关性;以及（3）确定IR SED颜色-颜色相关性是否意味着亮度之间的协方差。 这些结果将为高红移星系的应用提供处方，特别是从IR SED中推导无偏SFR和M_gas的处方，以及外推遥远星系中缺失的IR SED数据的处方，其中完整性，深度，该奖项反映了NSF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进行评估，被认为值得支持的搜索.

Observations with the new Atacama Large Millimeter-submillimeter Array (ALMA) facility, and with the next generation James Webb Space Telescope (JWST), will soon enable measurement of the star formation rate and the total available mass of gas contained in galaxies at high redshifts, providing critical information for studies of the growth of galaxies across cosmic time. These two measurements are made using different regions of the galaxy's spectrum. This work will determine how the numbers are related, and whether there are meaningful causal connections. This is essential to understanding how reliably these sorts of studies can actually derive physical parameters for the observed galaxies. The project has an integrated educational component: (1) summer research opportunities for undergraduate students from the surrounding area, exposing them to cutting-edge research; and (2) research experiences for teachers from local middle and elementary schools, helping to align them with the new "content driven" testing standards set by the State of Massachusetts, and with the requirements of the national Next Generation Science Standards.The synergy between ALMA and JWST will return the star formation rate (SFR) and gas mass (M_gas) of galaxies across the full range of luminosity and physical parameters at high redshifts, thus shedding light on the efficiency of star formation and the growth of galaxies as a function of cosmic time. Commonly, the SFR is derived from the "blue" side of the infrared spectral energy distribution (IR SED) of the dust, while M_gas is derived from the "red" side of the IR SED. However, the dichotomy between "blue" and "red" sides is artificial, and IR colors and monochromatic luminosities show correlations with each other. If there are underlying covariances, then they may be either helpful or detrimental to the use of the IR SED for deriving physical parameters. This project will determine such covariances, including their strengths, and establish whether they are physical (causal correlations) or trivial (such as some common cause) in nature. Bayesian inference methods applied to the ALMA and other archives will uncover and investigate covariances, to (1) investigate the correlation between mid-IR and far-IR/mm colors in a sample of nearby galaxies; (2) establish how well, and under what assumptions, physical models of dust emission account for the observed color-color correlation; and (3) establish whether the IR SED color-color correlation implies covariance between luminosities. The results will provide prescriptions for application to high redshift galaxies, specifically, recipes for deriving unbiased SFRs and M_gas from the IR SED and for extrapolating missing IR SED data in distant galaxies where issues of completeness, depth, and confusion become important.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.