Tomasz Nowakowski is a writer for Phys.org.
An international team of astronomy has detected a new kilonova that is associated with a nearby GRB. A paper published April 22 on arXiv.org shows that a finding could improve our understanding of the origin and nature of GRBs.
Transient events occur when two compact objects collide. They are thought to emit short gamma-ray bursts and strong radiation due to the decay of heavy r-process nuclei. The majority of elements heavier than iron may be created from kilonovae, the only observed source of r-process nucleosynthesis in the universe.
On December 21, 2021, the Burst Alert Telescope (BAT) onboard NASA's Swift spaceship spotted GRB 211211A at a distance of about 1.14 billion light years. It lasted 51.37 seconds and was close to the mean of the long-RGB population. The light curve of this burst consists of several overlaps.
A group of researchers led by Jillian Rastinejad of Northwestern University conducted a multi-wavelength follow-up observational campaign of GRB 211211A in order to shed more light on its nature. The Nordic Optical Telescope, Calar Alto Observatory, and Karl Jansky Very Large array were used for this purpose.
An uncatalogued source is fading rapidly over the first three days after the storm. A source with a K-band of 22.4 mag was detected with the Gemini-North telescope. 17 days after the burst was identified an associated supernova was conducted.
The results show that this is a kilonova. The assumed merger ejected a small amount of r-process-rich material. This is consistent with the merger of two stars with the same mass.
If we assume that the progenitorbinary consists of two neutron stars and use predictions from merger simulations to constrain the relative component mass and velocities, we get a good fit with a 1.4+1.3 solar massbinary.
According to the authors of the paper, the detection of a kilonova following a long GRB suggests that the current merger rates may not be accurate. They think that mergers related to long duration GRBs may contribute to the merger rate and r-process enrichment.
More information: J. C. Rastinejad et al, A Kilonova Following a Long-Duration Gamma-Ray Burst at 350 Mpc. arXiv:2204.10864v1 [astro-ph.HE], arxiv.org/abs/2204.10864The Science X Network will be launched in 2022.
Citation: Astronomers detect kilonova associated with a nearby gamma-ray burst (2022, May 4) retrieved 4 May 2022 from https://phys.org/news/2022-05-astronomers-kilonova-nearby-gamma-ray.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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