Stockholm university

Research project GREAT: GRavitationsstrålning och Elektromagnetiska Astrofysikaliska Transienter

The direct detection of gravitational waves has opened a completely new chapter in the study of gravity and the physics of the most compact objects in nature, black holes and neutron stars, especially using the electromagnetic counterparts

At the proposed VR forskningsmiljo ̈ GREAT we have create a new scientific environment combining observers and theorists that can carry out end-to-end simulations of the electromagnetic signals from scenarios involving mergers of compact objects accompanied by emission of gravitational radiation. Based on these simulations, we are interpreting these precious signals, as well as optimize the search strategies and perform the search for EM counterparts of GW events with the leading time-domain astronomical surveys.

Project description

On September 14, 2015 gravitational waves (GWs) were detected for the first time: the LIGO/Virgo team monitored the “chirping signal” and subsequent ring-down from the merger of two black holes. This watershed event, leading to the 2017 Nobel prize in Physics, confirmed a 100-year-old prediction of Einstein’s General Theory of Relativity; even more importantly, it opened up a completely new channel to observe the Universe. GW astronomy allows us to probe how the strongest gravitational fields warp space-time, how compact binary star systems contribute to the heaviest elements in Nature, how such systems form and, eventually, how their mergers can be used as probes of the expansion history of the Universe. These exciting prospects, however, hinge on the detection of the electromagnetic counterparts of the GW sources. The focus of the GREAT research environment from the onset was to explore strategies to maximize the detection of counterparts using optical and near-IR
On September 14, 2015 gravitational waves (GWs) were detected for the first time: the LIGO/Virgo team monitored the “chirping signal” and subsequent ring-down from the merger of two black holes. This watershed event, leading to the 2017 Nobel prize in Physics, confirmed a 100-year-old prediction of Einstein’s General Theory of Relativity; even more importantly, it opened up a completely new channel to observe the Universe. GW astronomy allows us to probe how the strongest gravitational fields warp space-time, how compact binary star systems contribute to the heaviest elements in Nature, how such systems form and, eventually, how their mergers can be used as probes of the expansion history of the Universe. These exciting prospects, however, hinge on the detection of the electromagnetic counterparts of the GW sources. The focus of the GREAT research environment from the onset was to explore strategies to maximize the detection of counterparts using optical and near-IR telescopes. On August 17, 2017, just about eight months after the start of the project, the merger of a binary neutron star system was first detected by LIGO/Virgo and, after 1.7 seconds, a short burst of gamma-rays (GRBs). In the following days, it was also detected in almost every region of the electromagnetic spectrum. This single event has already revolutionized astronomy, as it marked the beginning of the era of multi-messenger astronomy. Our team has been at the forefront of the field with regards to the follow-up observations and the interpretation of the physics involved in these so called “kilonovae”, e.g., with regards to the production of heavy elements in the universe and the use of these mergers as distance estimators in cosmology.

Project members

Project managers

Ariel Marcelo Goobar

Professor

Department of Physics
Ariel Goobar

Members

Jesper Sollerman

Professor

Department of Astronomy
Jesper

Stephan Rosswog

Professor

Department of Astronomy

Publications