Astrophysical (Magneto-Hydrodynamic) Jets and Astrophysical Quark Matter.

天体物理（磁流体动力学）喷流和天体物理夸克物质。

• 批准号: 261428-2013
• 负责人: Ouyed, Rachid
• 金额: $ 2.33万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=525219
• 关键词: Astrophysical; Magneto; Hydrodynamic; Jets; Quark

ASTROPHYSICAL JETS: These are long, highly collimated flows, with two back-to-back jets streaming away from their central source/object. They are seen in newly born stars, compact objects (like black holes or micro-quasars), active galactic nuclei, and are associated to gamma-ray bursts, the most energetic events in the Universe. Despite their different physical scales, jets have strong morphological similarities, but questions like - what physics do they share? - or - can we find a universal mechanism of acceleration and collimation that operates in all scales? - remain a matter of debate. We employ high-performance computational studies (in 3 Dimensions) of jets from young stars carried out to unprecedented resolution and simulation scales of hundreds of Astronomical Units -- allowing for the first time a one-to-one comparison to Hubble Space Telescope observations of jets. Our goal is to study their ejection, acceleration mechanisms using the codes and visualizations tools we built and, to confront models of jets against observed jet properties. Ultimately, this work could lead to an understanding of the physics of jets and their role in the formation of stars and galaxies. QUARK MATTER/STARS IN THE UNIVERSE: Quarks&Gluons are the underlying degrees of freedom for baryonic matter, but ordinarily remain hidden from us in the composite form of hadrons, requiring extreme temperature or pressure to liberate them -- forming the so-called Quark-Gluon Plasma. In our current Universe, quarks appear only in groups known as hadrons, but nature might produce this Quark-Gluon soup at the centers of ultra-dense stars such as neutron stars offering us a natural laboratory to study how nuclei-free quarks can form. We developed the BURN-UD code (a first if its kind) which captures the intricate details of how neutrons inside heavy neutron stars turn into quarks as they are squeezed by the extreme force of gravity. We discovered solutions where this transition occurs in an explosive manner with unique signatures; a phenomenon we called a QUARK-NOVA which might have serious implications to astrophysics. We plan to search for the predicted signatures and continue to improve our treatment of the physics of the explosion.

天体物理喷流：这些是长长的、高度平行的流动，有两个背靠背的喷流从它们的中心源/物体流出。它们出现在新生的恒星、致密天体(如黑洞或微类星体)、活动星系核中，并与宇宙中能量最高的伽马射线爆发有关。尽管喷流的物理尺度不同，但它们在形态上有很大的相似之处，但像这样的问题--它们有什么共同的物理学？--或者--我们能否找到一种在所有尺度上都能运行的通用加速和准直机制？--仍然是一个有争议的问题。我们利用对年轻恒星喷流的高性能计算研究(三维)，以前所未有的分辨率和数百个天文单位的模拟尺度进行研究--首次能够与哈勃太空望远镜对喷流的观测进行一对一的比较。我们的目标是使用我们建立的代码和可视化工具来研究它们的弹射、加速机制，并将喷流模型与观测到的喷流特性进行对抗。最终，这项工作可能会导致对喷流物理及其在恒星和星系形成中的作用的理解。夸克物质/宇宙中的恒星：夸克和胶子是重子物质的基本自由度，但通常以强子的复合形式对我们隐藏，需要极端的温度或压力才能释放它们--形成所谓的夸克-胶子等离子体。在我们目前的宇宙中，夸克只出现在被称为强子的群体中，但大自然可能会在中子星等超高密度恒星的中心产生这种夸克胶子汤，这为我们提供了一个天然的实验室来研究无核夸克是如何形成的。我们开发了Burn-UD代码(这是第一次)，它捕捉到了重中子星内的中子在受到极端引力挤压时如何变成夸克的复杂细节。我们发现了解决方案，这种转变以一种具有独特特征的爆炸性方式发生；我们称之为夸克-新星现象，可能会对天体物理学产生严重影响。我们计划搜索预测的信号，并继续改进我们对爆炸物理的处理。