Gamma-ray bursts and their afterglows

伽马射线暴及其余辉

• 批准号: 2895128
• 金额: --
• 依托单位: Lancaster University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2895128
• 关键词: Gamma; ray; bursts; their; afterglows

Gamma-ray bursts (GRBs) are brief, intense flashes of gamma-rays that are accompanied by longer lasting emission in the X-ray to radio wavelengths. The duration of the gamma-ray emission may be as short as a few milliseconds or may last for as long as a few hundred seconds, during which the GRB 'out-shines' all objects in the known universe. GRBs are divided, based on the duration of their gamma-ray emission, into two classes 'long' and 'short', which are associated, respectively, with the collapse of massive stars or the mergers of two compact objects (either two neutron stars or a neutron star and black hole). For his PhD, Sam will investigate the multi-wavelength afterglows of GRBs and what they can tell us about the environments GRBs explode in to, their central engines and the structure of their jets. He will initially begin by focusing on a correlation found in the optical, X-ray and GeV wavelength light curves. This correlation connects the early intrinsic brightness of GRB afterglows in these wavelengths with their average rate of decay, such that the brightest afterglows decay more quickly than the fainter ones. This correlation may be a result of an intrinsic property which regulates the energy release, with the energy of brighter afterglows being released more quickly than the fainter ones. Alternatively, this correlation may be due to a geometric effect caused by viewing angle, with the fainter slower decaying afterglows viewed more off-axis compared to their brighter and faster decaying counterparts. Sam will begin this investigation by determining whether the correlation exists also in the radio light curves.Sam will primarily work on GRBs observed by the NASA Swift satellite, the UK has key involvement in two of the three instruments onboard - the Ultra-violet and optical telescope and the X-ray telescope. Sam will be directly involved in Swift as a member of the UVOT team. He will participate in real time observation and follow-up of GRBs with UVOT and ESO telescopes through membership of the Swift and STARGATE teams. He will also participate in the search for the electromagnetic counterpart of gravitational waves through membership of ENGRAVE collaboration.

伽马射线爆发（GRB）是伽马射线的简短，强烈的闪光，伴随着X射线到无线电波长的持续发射。伽马射线发射的持续时间可能短几毫秒或可能持续几百秒，在此期间，GRB“掉”已知宇宙中的所有物体。根据其伽马射线发射的持续时间，将GRB分为两个类“长”和“短”，分别与大恒星或两个紧凑物体的合并（两个中子星或一个中子星和一个中子星和黑洞）相关。对于他的博士学位，SAM将研究GRB的多波长余星，以及他们可以告诉我们的有关环境的GRB爆炸，其中央引擎和喷气机的结构。最初，他将重点关注光学，X射线和GEV波长光曲线中的相关性。这种相关性将这些波长中GRB余潮的早期固有亮度与它们的平均衰减速率联系起来，因此，最亮的余星衰减比愚蠢的衰减更快。这种相关性可能是固有特性的结果，该特性调节能量释放，而更明亮的余星释放的能量比淡淡的能量更快。或者，这种相关性可能是由于视角引起的几何效应，与它们更明亮，更快的衰减对应物相比，衰减的后痛较慢的衰减较慢。 SAM将通过确定是否也存在于无线电曲线中的相关性来开始研究。SAM将主要在NASA Swift卫星观察到的GRB上，英国在船上的三种仪器中有关键参与 - 超紫罗兰和光学望远镜和X射线望远镜。 Sam将直接参与Swift，作为UVOT团队的成员。他将通过Swift和Stargate团队的会员身份参加与UVOT和ESO望远镜的实时观察和随访。他还将通过雕刻合作的成员资格来搜索引力波的电磁对应物。