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

点击翻译按钮获取中文摘要

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.