Black Hole Feedback and Galaxy Formation

Nagamine博士将联合收割机结合他对数百光年范围内新形成星系的流体动力学模拟与合作研究者Proga博士的模拟，后者在黑洞周围几光年的中心范围内进行盘吸积。 为了桥接它们之间的8个数量级，这些计算将通过使用“放大”技术以更高的分辨率连续重新模拟感兴趣的体积的中间规模运行来连接。 在最大规模的模拟中，黑洞既作为通过合并和吸积气体而增加质量的下沉粒子，也作为能量、动量和紫外线辐射的来源。 “汇”和“源”项都将用近似公式表示;模型预测将与星系际气体的观测结果以及在每个红移处看到的活动星系核的数量进行比较。 作为一个新的方面，PI将计算年轻恒星和活动核的紫外辐射如何传播到星系际气体中。 星系尺度的模拟将被用来发现气体流入星系内部的速度。 这为最后一个计算提供了一个外边界条件，它描述了中心黑洞周围的吸积盘。 在最后一个阶段，研究小组可以计算出黑洞应该向星系气体注入多少辐射和动量。 这将是第一次计算黑洞如何喂养和发光，当它位于一个星系的中心时，根据宇宙学的预测，这个星系本身正在与其他星系合并。 本科生将通过NSF资助的本科生暑期研究经验计划参加。 Nagamine博士将帮助规划UNLV校园内的一个新的公共天文馆，并将为其设计宇宙学展品。该团队将从模拟中生成图像和电影，用于公共宣传;他们的目标是制作足够高质量的IMAX电影的可视化效果。 两名调查员将继续在联合国LV组织的一系列公开讲座中发表演讲。

Dr. Nagamine will combine his hydrodynamic simulations of newly-forming galaxies in regions hundreds of light years across with those of co-investigator Dr. Proga, which follow disk accretion within the central few light years around a black hole. To bridge the 8 orders of magnitude in scale between them, these calculations will be linked by runs at intermediate scale using a 'zoom-in' technique of successively re-simulating an interesting volume at much higher resolution. Black holes are included in the largest-scale simulations both as sink particles that grow in mass by merging and by accreting gas, and as sources of energy, momentum and ultraviolet radiation. Both 'sink' and 'source' terms will be represented by approximate formulas; the model predictions will be compared with observations of the intergalactic gas, and the numbers of active galactic nuclei seen at each redshift. As a novel aspect, the PI will calculate how the ultraviolet radiation of young stars and active nuclei propagates out into the intergalactic gas. Galaxy-scale simulations will be used to find how fast gas will flow into the inner galaxy. This provides an outer boundary condition for the last calculation, which describes the accretion disk around the central black hole. At this last stage, the group can calculate how much radiation and momentum the black hole should inject back into the gas of the galaxy. These will be the first calculations of how a black hole feeds and shines, when it is in the center of a galaxy that is itself merging with others according to cosmological predictions.A graduate student and a postdoctoral fellow will be trained by their involvement in the research. Undergraduate students will participate through an NSF-funded summer Research Experiences for Undergraduates program. Dr. Nagamine will help to plan a new public planetarium on the UNLV campus, and will design cosmology exhibits for it. The team will generate images and movies made from the simulations, for use in public outreach; they aim to produce visualizations of sufficient quality for an IMAX movie. Both investigators will continue to give public lectures in a series organized by UNLV.