The gamma ray burst detected by MAGIC telescopes from the Canary Islands is the most powerful ever recorded . These Gamma Ray Bursts (GRBs) are brief, sudden cosmic bursts of the most violent events in the universe.
Decades have passed since the discovery of the first gamma-ray burst, yet some of its fundamental features remain unclear.
Now, after 20 years of searching for such a signal, scientists have seen it for the first time : two violent explosions in galaxies billions of light years away that produced the brightest light in the universe thanks to short eruptions from the most energetic form of light in the universe. This explosive event lasts from a fraction of a second to several minutes and emits the same amount of gamma rays as all the stars in the universe combined. And they can shine through almost the entire visible universe.
Explosion detection worldwide
On January 14, 2019, two space satellites independently discovered one of these gamma-ray bursts called The coordinates were immediately transmitted to astronomers around the world, including the MAGIC Collaboration, which has two 17-meter diameter Cherenkov telescopes in the Canary Island of La Palma. Just 50 seconds after the gamma-ray burst started, MAGIC was already watching it. It didn’t take long for GRB 190114C to set the record for the brightest known source of these energetic photons (apart from becoming the first very high-energy gamma-ray burst to be captured by MAGIC).
The second burst, captured in January, produced light that contained approximately 100 billion times more energy than the light that is visible to our human eyes.
“These are by far the highest energy photons ever discovered from a gamma ray burst,” said Elisa Bernardini, a gamma ray scientist, in a press release.
More than 300 scientists have studied the results
“Much of what we have learned about GRBs in the past two decades has come from observing their glows at lower energies,” NASA scientist Elizabeth Hays said in a statement.
Within 27 seconds of receiving the coordinates, astronomers in the Canary Islands rotated two Cherenkov Principal Atmospheric Gamma Imaging Telescopes (MAGIC) to that exact point in the sky. Photons flooded those telescopes for the next 20 minutes.
“After more than 45 years observing GRBs, we just confirmed the existence of another unknown component in their light glows, which dramatically increases the total energy budget of gamma rays,” said Chryssa Kouveliotou professor of physics at George University. Washington (USA).
GRB 190114C is unique in that the researchers were able to observe photons with teraelectronvolt (TeV) energies for the first time in their afterglow emission. From the Canary Islands, the researchers noted that this emission of TeV photons was 100 times more intense than the brightest known stable source at TeV energies, the Crab Nebula. However, unsurprisingly, this emission faded in about half an hour after the start of the event, while the residual glow emission in other parts of the spectrum persisted for much longer.
The scientists discovered that the shape of the observed spectrum of afterglow light was indicative of an emission process called the reverse Compton effect. This event supports the possibility that Compton reverse emission commonly occurs in gamma-ray bursts.
With the detection of the GRB 190114C, MAGIC opens a new window to study these huge gamma ray bursts and it seems that we will be able to detect many more GRBs in the energies of the TeV and better understand these fascinating cosmic explosions.
“Thanks to these new ground-based detections, we are looking at gamma rays from gamma ray bursts in a whole new way,” said Elizabeth Hays.
Referencia: MAGIC Collaboration/R. Mirzoyan et al.: “Observation of inverse Compton emission from a long γ-ray burst” – DOI: 10.1038/s41586-019-1754-6. MAGIC Collaboration/R. Mirzoyan et al.: “Teraelectronvolt emission from the γ-ray burst GRB 190114C” – DOI: 10.1038/s41586-019-1750-x. E. Ruiz-Velasco et al.: “A very-high-energy component deep in the γ-ray burst afterglow”- DOI: 10.1038/s41586-019-1743-9. Nature, 20 de noviembre de 2019.
