Collaborative Research: Cosmological All-wavelength Radiative Transfer (CART)

这个小组将研究新形成的星系的光和星系的活动核如何通过星际气体传播。他们将注意力集中在一个结束了宇宙历史约10亿年的时期，当时中性的星际气体被星系的紫外线电离。为了计算气体和暗物质是如何聚集在一起形成星系的，该小组将使用流体动力学模拟。他们将发展和改进他们的计算，以预测星系何时应该形成恒星，或者何时形成活跃的核。然后，从银河系出现的光子将使用李博士的三维辐射转移代码进行跟踪。该代码将得到改进，以处理莱曼-阿尔法光子、电离和非常小的尘埃颗粒的影响。该小组将制作大量高红移星系和类星体的模拟星表，描述它们从X射线到毫米波长的辐射，并包括21厘米处的氢线和莱曼阿尔法。两名研究生将通过参与研究进行培训。新的辐射传输代码和模拟星表将向天文学社区提供。这些星表总结了我们关于星系如何生长的理论的预测。该小组和其他人将通过将星表与目前和计划中的遥远星系深度调查中看到的情况进行比较，来检验这些理论。李博士和阿贝尔博士都在公共宣传方面有良好记录的机构工作，这个项目将产生吸引人的静止图像和电影，以说明当前关于星系形成的想法。

This group will investigate how the light of newly-forming galaxies and the active nuclei of galaxies propagates through the intergalactic gas. They focus attention on a period that ended about a billion years into cosmic history, when the neutral intergalactic gas was ionized by the ultraviolet light of galaxies. To calculate how gas and dark matter came together to make the galaxies, the group will use hydrodynamic simulations. They will develop and refine their calculations to predict when a galaxy should form stars, or develop an active nucleus. Then, the photons emerging from the galaxy will be tracked using Dr. Li's 3-dimensional radiative-transfer code. That code will be improved to handle Lyman-alpha photons, ionization, and the effect of very small dust grains. The group will produce large mock catalogs of high-redshift galaxies and quasars that describe their emission from X-ray to millimeter wavelengths, and include the hydrogen lines at 21cm and Lyman alpha. Two graduate students will be trained by participating in the research. The new radiative-transfer code, and the mock catalogs, will be made available to the astronomical community. Those catalogs summarize the predictions of our theories about how galaxies grow. This group and others will test those theories by comparing the catalogs with what is seen in current and planned deep surveys of distant galaxies. Both Dr. Li and Dr. Abel work at institutions with strong records in public outreach, and this project will yield attractive still images and movies to illustrate current ideas about galaxy formation.