Neutron star mergers, heavy elements and energetic explosions with multi-messenger astronomy

Описание: Dr Charlie Kilpatrick, Northwestern University

Neutron stars, the ultra-dense cores of massive stars that explode as supernovae, have been the subject of intense research since the 1960s as the sources of radio emission known as pulsars, gamma-ray bursts, and strong emitters of gravitational waves. In 2017, the LIGO and Virgo gravitational wave interferometers detected the merger of two neutron stars and localized them to a patch of the sky roughly the size of 150 full moons. My team led a localization campaign that discovered the optical emission from this source, allowing us for the first time to track a transient called a kilonova in exquisite detail at all electromagnetic wavelengths. We found that this kilonova was found in an extremely old environment where it likely lived for most of the history of the Universe, it was powered by extremely heavy radioactive elements, and it could only be explained via the merger of two neutron stars both slightly more massive than the Sun. I will discuss multiple observing campaigns conducted since 2017 to find the next gravitational wave detected kilonova, tackling challenges in observing large areas of the sky, characterizing kilonova candidates, and refining our models for the types of emission they can produce. Finally, I will present the first results from the multi-messenger Treasure TROVE, a new API-enabled tool and web platform that will amass electromagnetic data on candidate counterparts to gravitational wave events in real time and aid in follow up and discovery of the next kilonova from a neutron star merger.