天文學獎
2023

2023年度邵逸夫天文學獎平均頒予馬修・貝爾斯（Matthew Bailes）、鄧肯・洛里默（Duncan Lorimer）和莫拉・邁克勞克林 (Maura McLaughlin)，以表彰他們發現快速電波爆發 (FRBs)。馬修・貝爾斯是澳洲研究委員會 (ARC) 引力波發現卓越中心主任。鄧肯・洛里默是美國西維珍尼亞大學物理及天文學系教授暨臨時系主任及埃伯利文理學院研究副院長。莫拉・邁克勞克林是美國西維珍尼亞大學物理及天文學埃伯利家族傑出講座教授暨引力波及宇宙學中心主任。

快速電波爆發是天文學中最極端、最神秘的現象之一：它們是一種強烈的射電爆發，在千分之幾秒之內釋放相當於太陽數天輻射的能量。它們的爆發源比地球細小，處於非常遙遠的星系中。貝爾斯、洛里默、邁克勞克林 (與合作伙伴納爾凱維奇和克勞福德) 在2007年發表開創性研究論文，描述發現了首個快速電波爆發，並推斷出其來源的多項特性，特別是它的極遠距離、細小尺寸和巨大能量，他們還在論文中估計了快速電波爆發在宇宙中產生的速率，並強調它們可以用來探測宇宙的潛在功能。

Pulsars are among the most remarkable and exotic objects in the heavens: rapidly spinning neutron stars with a mass similar to the Sun’s, diameters of only a few tens of kilometers and magnetic fields a million million times stronger than the field we experience at the surface of the Earth. Pulsars emit beams of radio waves from their magnetic poles, which sweep across the Earth as the pulsars spin; these periodic pulses can be detected by Earth-based telescopes. On August 24 2001, during a search for pulsars in nearby galaxies, a telescope at the Parkes Observatory in Australia recorded a brief but unusually strong burst of radio emission. This event lay undetected in the archives of that search for more than half a decade, until it was found by David Narkevic, a student working with Duncan Lorimer and Maura McLaughlin at West Virginia University on a search for single pulses from pulsars with strongly variable radio emission. The arrival time of the burst was dispersed, that is, it changed with frequency, a characteristic of astrophysical signals such as those from pulsars that have propagated through the plasma of ionized gas that fills much of our Milky Way and other galaxies. However, the dependence of arrival time on frequency was far larger than for any known pulsar. Lorimer, McLaughlin, Bailes and their collaborators recognized that this dependence implied that the mysterious source – now known as the “Lorimer burst” – lay far outside our own Milky Way, roughly 100,000 times further than the typical pulsar and so far away that the burst was emitted over a billion years ago. They also showed that despite this enormous distance and the correspondingly huge energy requirements, the object emitting the burst had to be very small – the finite speed of light and the short duration of the signal implied that the burst must have come from a region smaller than the Earth.