Extreme Physics with Pulsars and Radio Transients

脉冲星和无线电瞬变的极端物理

• 批准号: RGPIN-2017-04057
• 负责人: Stairs, Ingrid
• 金额: $ 5.25万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=665798
• 关键词: Extreme; Physics; Pulsars; Radio; Transients

Compact stellar objects such as neutron stars offer the opportunity to probe a wide range of fundamental physics problems. Many neutron stars emit lighthouse-like radio beams, which may hit the Earth once per rotation and cause us to label the star a pulsar. The fastest-spinning pulsars rotate several hundred times per second and can rival the stability of atomic clocks on short timescales. An array of these millisecond pulsars, spread across the sky, can be used to make a direct detection of gravitational waves passing near the Earth. The main sources of these gravitational waves is predicted to be pairs of supermassive black holes as the centres of galaxies that have recently undergone mergers, highly complementary to the stellar-mass black holes recently detected by the Laser Interferometric Gravitational-wave Observatory (LIGO). The pulsar timing array research proposed here will enhance the effectiveness of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), by improving the current data-reduction methods and by bringing in entirely new data which will address systematics due to variations in the interstellar medium. These data will come from the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope under construction in Penticton, B.C. Simultaneously with its original cosmology mission, CHIME will provide daily data on the Northen NANOGrav pulsars, allowing us to model the variations in the interstellar medium in more detail than currently possible and providing corrections to the higher-frequency NANOGrav data. This project will accelerate the timeline for NANOGrav to make a detection of gravitational waves. CHIME will also provide dense data sets on numerous other interesting pulsars, including relativistic binaries, which are another long-term interest of this research group.******CHIME holds still more promise, for tackling the still-mysterious Fast Radio Bursts (FRBs). These are single spikes of radio emission, almost certainly extragalactic in origin, seen with some of the largest radio telescopes in existence. One of these sources has now been seen to repeat, but it is unclear at present whether there are two classes of source. What causes the bursts is still unknown-- in fact there are more published ideas than bursts at present -- but the inferred brightness and short timescale indicate that the involvement of a compact object such as a neutron star is likely. With a dedicated second instrument on CHIME, we expect to detect several tens of FRBs per day; the vastly improved statistics will constrain models and may help to localize the bursts well enough to identify host galaxies.

紧凑的恒星物体，如中子星，提供了探索广泛的基本物理问题的机会。 许多中子星发出灯塔般的无线电波束，每转一圈可能会击中地球一次，使我们将这颗星星称为脉冲星。 旋转最快的恒星每秒旋转数百次，在短时间尺度上可以与原子钟的稳定性相媲美。 这些毫秒级的射电望远镜阵列遍布天空，可以用来直接探测地球附近的引力波。 这些引力波的主要来源被预测为成对的超大质量黑洞，它们是最近经历合并的星系的中心，与激光干涉引力波天文台（LIGO）最近探测到的恒星质量黑洞高度互补。 这里提出的脉冲星定时阵列研究将提高北美纳赫兹引力波天文台（NANOGrav）的有效性，通过改进目前的数据简化方法，并引入全新的数据，这些数据将解决星际介质变化引起的系统性问题。 这些数据将来自加拿大氢强度测绘实验（CHIME）望远镜正在建设中彭蒂克顿，不列颠哥伦比亚省的同时，其原始的宇宙学使命，CHIME将提供每日数据的北NANOGrav天文台，使我们能够模拟星际介质中的变化比目前可能的更详细，并提供更高的校正频率NANOGrav数据。 该项目将加快NANOGrav探测引力波的时间轴。 CHIME还将提供许多其他有趣的双星的密集数据集，包括相对论双星，这是该研究小组的另一个长期兴趣。CHIME在解决仍然神秘的快速射电暴（FRB）方面还有更多的希望。 这些是射电发射的单个尖峰，几乎可以肯定起源于银河系外，用一些现存的最大的射电望远镜可以看到。 其中一个来源现在被认为是重复的，但目前还不清楚是否有两类来源。 是什么导致了爆发仍然是未知的--事实上，目前发表的想法比爆发还多--但推断的亮度和短时间尺度表明，像中子星星这样的致密物体很可能参与其中。 有了CHIME上的第二台专用仪器，我们预计每天可以检测到几十个FRB;大大改进的统计数据将限制模型，并可能有助于定位爆发，以识别宿主星系。