Neutron Stars as Probes for the Structure of Dense Nuclear Matter

中子星作为稠密核物质结构的探测器

• 批准号: 0457329
• 负责人: Fridolin Weber
• 金额: $ 21万
• 依托单位: San Diego State University Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0457329&HistoricalAwards=false
• 关键词: Neutron; Stars; Probes; Structure; Dense

Neutron Stars as Probes for the Structure of Dense Nuclear MatterFridolin Weber, San Diego State University, San Diego, CaliforniaNeutron stars contain matter in one of the densest forms found in theUniverse (a thimble full of such matter would have a mass of onebillion tons) which, together with the unprecedented progress inobservational astronomy, makes such stars superb astrophysicallaboratories for a broad range of fascinating physical studies. Theseinclude the exploration of nuclear processes in an environmentextremely rich of electrons and neutrons, and the formation of newstates of matter in the cores of such objects, like a plasma of quarksand gluons which is being sought at the most powerful terrestrialparticle colliders. This NSF supported research project aims atexploring such processes from observed neutron star data. It isdivided into two major activities.The first activity deals with X-ray neutron stars accreting matterfrom companions. Such neutron stars accrete typically many millionsof tons of matter per second, which hit the stellar surface at asignificant fraction of the speed of light. This leads tothermonuclear reactions on the stellar surface whose ashes gravitategradually inward, causing significant changes (e.g. nuclear fusionreactions) in the star's crust. The major goal of this activity is toexplore the impact of these thermonuclear reactions on the thermalevolution of accreting neutron stars.The second activity concerns our understanding of the fundamentalphysics realized in the ultra-dense core of neutron stars, whereneutrons and protons might be broken up into their quark constituents,creating a new state of matter known as quark matter. If quark matterexists in the cores of neutron stars, it will be a colorsuperconductor whose condensation pattern is very complex. It has alsobeen theorized that neutron stars could in fact be quark stars,objects made entirely of quark matter. In the framework of thisactivity, research on potential astrophysical signatures signaling theexistence of quark matter in "neutron" stars will be carried out.These research activities are crucial to obtain the full physicspotential of the investments that are made in astrophysical detectors,at Jefferson Lab, the Relativistic Heavy Ion Collider (RHIC), as wellas new investments that are recommended for the Rare IsotopeAccelerator (RIA).The researchers and students involved in this project will developmulti-media lectures on how stars work and present them to middleand high school students and teachers in the San Diego area.

中子星作为致密核物质结构的探测器弗里多林·韦伯，圣地亚哥州立大学，圣地亚哥，加利福尼亚中子星包含的物质是宇宙中发现的密度最大的物质之一（一个装满这种物质的顶针的质量将达到10亿吨），这与观测天文学中前所未有的进步一起，使这些恒星成为极好的天体物理学实验室，可以进行广泛的有趣的物理研究。这包括在一个极其丰富的电子和中子环境中探索核过程，以及在这些物体的核心形成新的物质状态，比如夸克和胶子的等离子体，这是在最强大的陆地粒子对撞机上正在寻找的。这项由美国国家科学基金会支持的研究项目旨在从观测到的中子星数据中探索这一过程。它分为两个主要活动。第一个活动涉及x射线中子星从同伴那里吸积物质。这样的中子星通常每秒吸积数百万吨物质，这些物质以光速的相当一部分撞击恒星表面。这导致恒星表面的热核反应，其灰烬逐渐向内吸引，导致恒星地壳发生重大变化（例如核聚变反应）。这项活动的主要目标是探索这些热核反应对吸积中子星热演化的影响。第二项活动涉及到我们对中子星超密集核心中实现的基本物理学的理解，在那里，中子和质子可能被分解成它们的夸克成分，创造出一种被称为夸克物质的新物质状态。如果夸克物质存在于中子星核心，它将是一种凝结模式非常复杂的彩色超导体。也有理论认为，中子星实际上可能是夸克星，完全由夸克物质构成的物体。在这项活动的框架内，将对“中子星”中存在夸克物质的潜在天体物理特征进行研究。这些研究活动对于获得杰斐逊实验室天体物理探测器、相对论重离子对撞机（RHIC）以及稀有同位素加速器（RIA）的新投资的全部物理潜力至关重要。参与该项目的研究人员和学生将开发有关明星如何工作的多媒体讲座，并将其呈现给圣地亚哥地区的初中和高中学生和教师。