What Is Kilonova Emission? Find Out About The Rare Astronomical Event And Gamma Ray Burst (GRB)
Astronomers have spotted the first astronomical event in which a long gamma-ray explodes (GRBs) along with a rare kilonova emission while tracing a burst of high-energy light detected in 2021.
This was on the outskirts of the Milky Way located approximately 1 billion light-years away.
The 3.6 m Devasthal Optical Telescope(DOT) observed the earliest phase of a kilonova. Its vital information radically changed the understanding of scientists about the origin of GRBs.
What are GRBs?
- The Powerful astronomical cosmic bursts of high-energy gamma-rays are called GRBs that emit more energy in a few seconds than our Sun will emit in its lifetime
- It has two distinct emission phases:
- The short-lived prompt emission (the initial burst phase that emits gamma rays).
- A long-lived multi-wavelength afterglow phase.
What is Kilonova?
- Kilonova emissions are the radiations emerging from the merger of neutron stars or any binary system.
- They can also be associated with short GRBs.
- They are visible as infrared light with short-period GRBs
- It is also known as a potential source of gravitational waves.
- A hypothesis says that the heat produced by the radioactive decay of heavier elements may emit kilonova.
- This process can produce heavier elements, such as gold and platinum as well.
- Only a few telescopes on Earth, including the 3.6-m DOT of the Aryabhatta Research Institute of Observational Sciences (ARIES), can detect kilonova and gravitational wave objects at these wavelengths up to faint limits as it's a tedious task.
How did they detect it?
- When The scientists from the ARIES, used data from the 3.6 m DOT of the ARIES along with other telescopes, including Hubble Space Telescope in studying the oGRB (GRB 211211A), detected by the NASA’s Neil Gehrels Swift Observatory and the Fermi Gamma-ray Space Telescope on December 11, 2021 they saw that the high-energy outburst lasted about a minute.
- Follow-up observations taken from the 3.6-meter Devasthal Optical Telescope identified a kilonova.
- In this event, according to the observations of the 3.6 m DOT both thermal and non-thermal emissions were included in the spectral energy distribution of the afterglow.
What is 3.6 m Devasthal Optical Telescope(DOT)-
- The clear-aperture Ritchey–Chrétien telescope is built by Aryabhatta Research Institute of Observational Sciences(ARIES) which is located at the Devasthal Observatory site near Nainital, Kumaon, India.
- ARIES operates another 1.3m telescope at the same location.
- The Devasthal Optical Telescope(DOT) telescope was activated remotely in March 2016 by Indian and Belgian Prime Ministers.
- The telescope optics has been It is currently the largest reflecting telescope in Asia and was built in collaboration with the Belgian firm Advanced Mechanical and Optical System (AMOS).
- The telescope fills a large longitudinal gap in the 4m class of telescopes in the Asia region.
- The telescope has an optical spectrograph, a CCD imager, and a near-infrared spectrograph.
- It is also the first telescope of its kind in India that features an active optics system.
- It also features a wavefront sensor and pneumatic actuators which compensates for small distortions in the shape of the 4.3-tonne mirror due to gravity or atmospheric aberrations.
“But the after-glow properties of this event clearly lean towards kilonova. This could then mean that some processes are common between the long and short GRBs. The new study results clearly indicate that our classification of long and short GRBs now stands challenged,”
said Shashi Bhushan Pandey, Principal Investigator of the DOT and one of the authors of the paper.
This international collaborative study included researchers from:
- Arizona State University
- Los Alamos National Laboratory
- the University of Rome, University of Maryland
- The George Washington University
- NASA Goddard Space Flight Centre
- Permiter Institute of Theoretical Physics
- Canada, The Pennsylvania State University
- Pandit Ravishakar Shukla University
- Tokyo Institute of Technology
- Deen Dayal Upadhyay Gorakhpur University
- Boise State University, University of Bath
- Unidad Asociada al CSIS and Instituto de Astrofisica de Andalucia in Spain.
“DOT located in Nainital enjoys the longitudinal advantage which facilitated the viewing of the event. If there was no 3.6 metre optical telescope available, we could not have detected the event from here as well. To study more such events, we will need to build more sensitive instruments,” added Pandey.
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