Collaborative Research: The Definitive Follow-up Campaign for Fast Radio Bursts

快速射电爆发(FRB)是持续时间仅为毫秒的射电发射的瞬时脉冲。众所周知，它们来自我们自己的星系以外的星系，现在是天体物理研究的一个高度密集的区域，到目前为止已经探测到了1000多个FRB。加州大学圣克鲁斯分校、西北大学和玛丽亚·米切尔天文台(MMO)之间的一个研究团队构成了FRB后续行动(F4)团队的核心，该团队自2019年以来一直由NSF资助，以观察FRB并将它们与其宿主星系联系起来。这使得该团队能够开始使用FRB信号来探测宇宙，并对整个宇宙中处于星系外高度扩散状态的重子(亚原子粒子，主要是质子和中子)进行新的普查。目前的NSF奖扩展了这项工作，允许F4通过对两个精确定位的FRB的新调查的后续观察，将其观测影响增加一个数量级，使它们能够研究宇宙学、重子分布和确定FRB的前身。该奖项还将支持在MMO举办的学士学位后“桥梁”项目的学生，以吸引和留住有才华的和传统上代表较少的学生，长期目标是增加他们在STEM领域的参与度和领导力。所有的研究人员都将参与MMO的许多外展活动。在这笔赠款期间，F4团队将获取、分析和传播天空中数百个FRB的宿主星系的深度、多波段成像和光谱。对于数十个FRB场，他们将获得成像和多目标光谱，以识别中间的星系晕并绘制前景大尺度结构图。这些数据和导出的量(例如红移(Z)和恒星质量)，加上对FRB的测量(例如色散度(Dm)和旋转度(Rm))将使三个主要的科学推动力成为可能：(1)宇宙学：第一次在统计上稳健地确定麦夸特关系(Dm与z)，导致对哈勃参数的新的和补充的估计；(2)星系形成：推断银晕中重子的径向分布，限制环星系介质的磁场和气体密度；以及(3)FRB的前身：测试为生产FRB而调用的许多模型，并使用无线电、光学和X射线波长的快速后续成像来解决FRB的发射机制。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Fast radio bursts (FRBs) are transient pulses of radio emission lasting only milliseconds. They are known to be coming from galaxies outside our own and are now a highly intense area of astrophysical pursuit, with over a thousand FRBs detected to date. A research team between the University of California Santa Cruz, Northwestern University and the Maria Mitchell Observatory (MMO) forms the core of the Fast and Fortunate for FRB Follow-up (F4) team, which has been funded by the NSF since 2019 to observe FRBs and associate them with their host galaxies. This has enabled the team to start to use FRB signals to probe the universe and to make a new census of the baryons (subatomic particles, mostly protons and neutrons) in a highly diffuse state outside of galaxies throughout the universe. This current NSF award extends this work to allow F4 to increase its observational impact by an order of magnitude through follow-up observations of two new surveys of precisely localized FRBs, allowing them to study cosmology, baryon distribution and identify FRB progenitors. This award will also support students in a postbaccalaureate 'Bridge' program hosted at the MMO for attracting and retaining talented and traditionally underrepresented students, with a long-term goal of increasing their participation and leadership in STEM fields. All of the investigators will engage in the many outreach activities of the MMO.During the period of this grant, the F4 team will acquire, analyze, and disseminate deep, multi-band imaging and spectroscopy on the host galaxies of hundreds of FRBs across the sky. For many tens of FRB fields, they will obtain imaging and multi-object spectroscopy to identify intervening galactic halos and map the foreground large-scale structure. These data and derived quantities (e.g. redshifts (z) and stellar masses), together with measurements of the FRBs (e.g. dispersion measure (DM) and rotation measure (RM)) will enable three major scientific thrusts: (1) cosmology: the first statistically robust determination of the Macquart relation (DM vs. z), leading to a new and complementary estimate of the Hubble parameter; (2) galaxy formation: inferring the radial distribution of baryons in galactic halos and constraining the magnetic fields and gas density of the circumgalactic medium; and (3) FRB progenitors: testing the many models invoked to produce FRBs and using rapid follow-up imaging at radio, optical and X-ray wavelengths to resolve FRB emission mechanisms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.