To spot them, scientists, for that reason, use space-based gamma-ray telescopes that, when activated, send out automatic immediate messages to Earth. This allows astronomers to follow up the detections with Earth-based telescopes, to try to find a less energetic “afterglow” that often follows the gamma rays.
Beating an entire galaxy
On 9 October 2022, ESAs INTEGRAL, NASAs Swift and Fermi satellites, and other space observatories found the gamma-ray burst which was, appropriately, named GRB 221009A. This led Daniele Bjørn Malesani, astronomer at Radboud University in the Netherlands and affiliated scientist at the Cosmic Dawn Center, to point the Very Large Telescope (VLT) in Chile towards the instructions of GRB 221009A.
Using the X-shooter spectrograph installed at the VLT, the resulting spectrum allowed Malesani and his group to measure the specific distance to GRB 221009A. Although the host galaxy of the burst ended up to lie more than two billion lightyears away, this in fact makes it one of the most close-by bursts Additionally, with a secure distance the team was also able to compute the overall amount of energy launched from the burst.
Even Webb has shortcomings
Kasper Heintz, assistant teacher at the Cosmic Dawn Center, took part in both research studies. He describes: ” Gamma-ray bursts like GRB 221009A are expected to take off together with a supernova whose light should add to the burst itself. But for this burst, despite Webbs substantial mirror it could not find persuading proof for a bright supernova.”
So, was the supernova simply fainter than regular, or was it missing completely? The jury is still out, and there are more surprises to come from this unique strange event.
The short articles have just been accepted for publication in, respectively, Astronomy & & Astrophysics and Astrophysical Journal Letters.
The enigmatic gamma-ray bursts.
Gamma-ray bursts were first discovered in 1967 by the Vela satellite, constructed to keep track of the sky for possible tests of nuclear weapons, which would be an infraction of the 1963 Nuclear Test Ban Treaty. First believed to stem from neighboring sources within our own galaxy, more delicate area observatories revealed, in the 1990s, that they should originate from far outside the Milky Way, dispersed over the entire Universe.
The transient nature of the bursts made them tough to study, but because the late 1990s astronomers have actually had the ability to detect also their less energetic afterglow, from X-rays to optical light, to the infrared, helping to develop a theory of their origin.
” Gamma-ray bursts are constantly energetic, however this one was definitely impressive: During the 290 seconds that it lasted, GRB 221009A released approximately 1,000 times as much energy as our Sun has actually given off during all of its lifetime of 4.5 billion years,” states Malesani.
Another method to put it is that the burst for a brief duration of time was more luminescent that the combined light of all the numerous billions of stars in the Milky Way.
As is normal, this computation presumes that GRB 221009A has actually released the very same amount of energy in all instructions. Most likely though, the energy in “focused” in a narrow beam, in the direction of which we happen to lie. The overall energy is therefore somewhat smaller sized, although still very high.
And in any rate, it is the most energetic gamma-ray burst ever spotted, 70 times brighter than ever seen before. It was even reported to affect the Earths ionosphere.
” Theoretically, we would anticipate such an effective event to happen only once in 10,000 years,” describes Malesani. ” This makes us question if our detection is just large luck, of if theres something were misconstruing about the nature of gamma-ray bursts.”
Followed up with James Webb
GRB 221009A was also followed up at longer wavelengths with the James Webb Space Telescope. These observations were led by Andrew Levan, likewise at Radboud University, although Malesani and other DAWNers likewise belonged of the team.
These observations permitted the astronomers to further define the gamma-ray burst. The James Webb telescope was especially helpful due to the fact that the burst happens to lie, by an unlucky chance, behind a thick layer of cosmic dust inside the Milky Way galaxy. This has nothing to do with the burst itself, however makes it harder to analyze the results, as it dims the light from the burst. Webb looked at the afterglow in the mid infrared, which is much less impacted by dust, providing a much better view of the event.
Artists illustration of a gamma-ray burst resulting from a collapsing star, ejecting particles and radiation in a narrow jet. GRB 221009A, the most energetic gamma-ray burst ever recorded, released 1,000 times more energy than the Suns lifetime output. Observed with the VLT and James Webb Space Telescope, this occasion left scientists puzzled about gamma-ray bursts nature and the possible lack of an accompanying supernova. Credit: Soheb Mandhai
Gamma-ray bursts are the most energetic explosions in the Universe, marking the end of a stars life. An especially intense burst, GRB 221009, was just recently spotted by numerous space telescopes. A team of researchers led by astronomers at the Cosmic Dawn Center measured the precise distance to the burst, allowing them to compute the total energy launched: During its period of simply 5 minutes, it released 1,000 times more energy than our Sun has actually released throughout its 4.5 billion year life, making the burst the single most energetic ever spotted.
Gamma-ray bursts are the most energetic and luminescent occasions known to take place in deep space. Short-lived flashes of gamma-rays that generally last from a tenth of a 2nd to less than an hour, gamma-ray bursts might for a short time period outshine whole galaxies. The explosions are thought to be triggered by the collapse of huge stars, the crash of neutron stars, or the combining of a neutron star and a great void.
We have understood about their existence for 60 years, there is still much to discover about these interesting events. Not just are they short-term and happen at random places in the sky; gamma rays are also primarily soaked up by our environment restraining their detection from Earth.
For more on these discoveries:
References:
” The brightest GRB ever found: GRB 221009A as an extremely luminous event at z = 0.151″ by D. B. Malesani, A. J. Levan, L. Izzo, A. de Ugarte Postigo, G. Ghirlanda, K. E. Heintz, D. A. Kann, G. P. Lamb, J. Palmerio, O. S. Salafia, R. Salvaterra, N. R. Tanvir, J. F. Agüí Fernández, S. Campana, A. A. Chrimes, P. DAvanzo, V. DElia, M. Della Valle, M. De Pasquale, J. P. U. Fynbo, N. Gaspari, B. P. Gompertz, D. H. Hartmann, J. Hjorth, P. Jakobsson, E. Palazzi, E. Pian, G. Pugliese, M. E. Ravasio, A. Rossi, A. Saccardi, P. Schady, B. Schneider, J. Sollerman, R. L. C. Starling, C. C. Thöne, A. J. van der Horst, S. D. Vergani, D. Watson, K. Wiersema, D. Xu and T. Zafar, Accepted, Astronomy & & Astrophysics.DOI: 10.48550/ arXiv.2302.07891.
” The First JWST Spectrum of a GRB Afterglow: No Bright Supernova in Observations of the Brightest GRB of perpetuity, GRB 221009A” by A. J. Levan, G. P. Lamb, B. Schneider, J. Hjorth, T. Zafar, A. de Ugarte Postigo, B. Sargent, S. E. Mullally, L. Izzo, P. DAvanzo, E. Burns, J. F. Agüí Fernández, T. Barclay, M. G. Bernardini, K. Bhirombhakdi, M. Bremer, R. Brivio, S. Campana, A. A. Chrimes, V. DElia, M. Della Valle, M. De Pasquale, M. Ferro, W. Fong, A. S. Fruchter, J. P. U. Fynbo, N. Gaspari, B. P. Gompertz, D. H. Hartmann, C. L. Hedges, K. E. Heintz, K. Hotokezaka, P. Jakobsson, D. A. Kann, J. A. Kennea, T. Laskar, E. Le Floc h, D. B. Malesani, A. Melandri, B. D. Metzger, S. R. Oates, E. Pian, S. Piranomonte, G. Pugliese, J. L. Racusin, J. C. Rastinejad, M. E. Ravasio, A. Rossi, A. Saccardi, R. Salvaterra, B. Sbarufatti, R. L. C. Starling, N. R. Tanvir, C. C. Thöne, A. J. van der Horst, S. D. Vergani, D. Watson, K. Wiersema, R. A. M. J. Wijers and Dong Xu, 28 March 2023, The Astrophysical Journal Letters.DOI: 10.3847/ 2041-8213/ acc2c1.
GRB 221009A, the most energetic gamma-ray burst ever tape-recorded, launched 1,000 times more energy than the Suns lifetime output. Observed with the VLT and James Webb Space Telescope, this event left researchers puzzled about gamma-ray bursts nature and the possible lack of an accompanying supernova. A group of scientists led by astronomers at the Cosmic Dawn Center measured the specific range to the burst, enabling them to determine the total energy launched: During its period of simply 5 minutes, it released 1,000 times more energy than our Sun has produced throughout its 4.5 billion year life, making the burst the single most energetic ever detected.
Gamma-ray bursts are the most luminous and energetic events known to take place in the Universe. Temporary flashes of gamma-rays that usually last from a tenth of a 2nd to less than an hour, gamma-ray bursts may for a quick period of time outperform entire galaxies.
