Towards a Comprehensive Understanding of Brown Dwarf Atmospheres

全面了解棕矮星大气

• 批准号: 1517015
• 负责人: Jonathan Fortney
• 金额: $ 24.53万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1517015&HistoricalAwards=false
• 关键词: Towards; Comprehensive; Understanding; Brown; Dwarf

Brown dwarfs are objects that sit at the boundary between stars and planets. Although they form like stars, they do not have hydrogen fusion, so they cool over billions of years down to temperatures similar to those of planets. By studying the the infrared heat radiation given off by brown dwarfs, we can understand the physics and chemistry and their atmospheres. This project involves the work of graduate students and high school students, who will receive training in advanced computational techniques, which will allow them to create computer models of brown dwarf atmospheres. These results will be compared to observations made from large telescopes in order to determine the physical properties within brown dwarf atmospheres. The proposal team will carry out a significant expansion of the phase space of brown dwarf model atmospheres. They will investigate the role of metallicity, non-solar carbon-to-oxygen ratios, varied cloud thickness, cloud coverage fraction, surface gravity, and other factors in shaping brown dwarf spectra. This extensive grid of radiative-convective "forward models" will map out the phase space of brown dwarf atmospheric chemistry and physics. For the first time we will gain a quantitative understanding of the reasons behind mismatches between spectral observations and models. The bulk of the science will be performed by a graduate student, in concert with high school interns who will be mentored each summer.

褐矮星是位于恒星和行星之间的物体。 虽然它们的形成像恒星一样，但它们没有氢聚变，因此它们在数十亿年内冷却到与行星相似的温度。 通过研究褐矮星发出的红外热辐射，我们可以了解它们的物理、化学和大气。 该项目涉及研究生和高中生的工作，他们将接受先进计算技术的培训，这将使他们能够创建褐矮星大气层的计算机模型。 这些结果将与大型望远镜的观测结果进行比较，以确定棕矮星大气层内的物理特性。提案小组将对褐矮星模型大气的相空间进行重大扩展。 他们将研究金属丰度，非太阳碳氧比，不同的云厚度，云覆盖率，表面重力和其他因素在形成褐矮星光谱中的作用。这个广泛的辐射对流“正演模型”网格将绘制出褐矮星大气化学和物理的相空间。 这是第一次，我们将获得光谱观测和模型之间不匹配背后的原因的定量理解。 大部分的科学研究将由一名研究生和每年夏天接受指导的高中实习生共同完成。