GSFC: Fermi, Swift Enable a New Era in Gamma-ray Science

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GSFC: Fermi, Swift Enable a New Era in Gamma-ray Science

Post by bystander » Wed Nov 20, 2019 9:27 pm

Fermi, Swift Enable a New Era in Gamma-ray Science
NASA | GSFC | Fermi | Swift | 2019 Nov 20
The fading afterglow of GRB 190114C and its home galaxy were imaged by the Hubble
Space Telescope on Feb. 11 and March 12, 2019. The difference between these images
reveals a faint, short-lived glow (center of the green circle) located about 800 light-
years from the galaxy’s core. Blue colors beyond the core signal the presence of hot,
young stars, indicating that this is a spiral galaxy somewhat similar to our own. It is
located about 4.5 billion light-years away in the constellation Fornax.
Credits: NASA, ESA, and V. Acciari et al. 2019 Nature

A pair of distant explosions discovered by NASA’s Fermi Gamma-ray Space Telescope and Neil Gehrels Swift Observatory have produced the highest-energy light yet seen from these events, called gamma-ray bursts (GRBs). The record-setting detections, made by two different ground-based observatories, provide new insights into the mechanisms driving gamma-ray bursts.

Astronomers first recognized the GRB phenomenon 46 years ago. The blasts appear at random locations in the sky about once a day, on average. ...

On Jan. 14, 2019, just before 4 p.m. EST, both the Fermi and Swift satellites detected a spike of gamma rays from the constellation Fornax. The missions alerted the astronomical community to the location of the burst, dubbed GRB 190114C.

One facility receiving the alerts was the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) observatory, located on La Palma in the Canary Islands, Spain. Both of its 17-meter telescopes automatically turned to the site of the fading burst. They began observing the GRB just 50 seconds after it was discovered and captured the most energetic gamma rays yet seen from these events.

The energy of visible light ranges from about 2 to 3 electron volts. In 2013, Fermi’s Large Area Telescope (LAT) detected light reaching an energy of 95 billion electron volts (GeV), then the highest seen from a burst. This falls just shy of 100 GeV, the threshold for so-called very high-energy (VHE) gamma rays. With GRB 190114C, MAGIC became the first facility to report unambiguous VHE emission, with energies up to a trillion electron volts (1 TeV). That’s 10 times the peak energy Fermi has seen to date. ...

Another paper presents observations of a different burst, which Fermi and Swift both discovered on July 20, 2018. Ten hours after their alerts, the High Energy Stereoscopic System (H.E.S.S.) pointed its large, 28-meter gamma-ray telescope to the location of the burst, called GRB 180720B. A careful analysis carried out during the weeks following the event revealed that H.E.S.S. clearly detected VHE gamma rays with energies up to 440 GeV. Even more remarkable, the glow continued for two hours following the start of the observation. Catching this emission so long after the GRB’s detection is both a surprise and an important new discovery. ...

Hubble Studies Gamma-Ray Burst with the Highest Energy Ever Seen
ESA Hubble Science Release | 2019 Nov 20

Hubble Studies Gamma-Ray Burst with Highest Energy Ever Seen
NASA | GSFC | STScI | HubbleSite | 2019 Nov 20

Gamma-Ray Bursts with a High Radiant Power
Max Planck Institute for Nuclear Physics (MPIK) | 2019 Nov 20

First Detection of GRB Afterglow in Very-High-Energy Gamma Light
Kavli Institute for the Physics and Mathematics of the Universe (KIMPU) | 2019 Nov 20

Gamma-Ray Bursts with Record Energy Detected
Deutsches Elektronen-Synchrotron (DESY) | 2019 Nov 20

MAGIC Telescopes See Most Epic Explosion
International Center for Radio Astronomy Research (ICRAR) | 2019 Nov 20

Cosmic Explosions: Detecting the Highest-Energy Light
University College, London | 2019 Nov 20

Extreme Emission Seen from γ-ray Bursts
Nature News & Views | 2019 Nov 20

GRB 180720B: The First Gamma-Ray Burst Detected in the Very-High-Energy Band
High Energy Stereoscopic System (H.E.S.S.) | 2019 Dec

Teraelectronvolt emission from the γ-ray burst GRB 190114C ~ MAGIC Collaboration, V. A. Acciari et al Observation of inverse Compton emission from a long γ-ray burst ~ MAGIC Collaboration, Fermi and Swift Teams, P. Veres et al A very-high-energy component deep in the γ-ray burst afterglow ~ HESS Collaboration, H. Abdalla et al Fermi and Swift Observations of GRB 190114C: Tracing the Evolution
of High-Energy Emission from Prompt to Afterglow
~ M. Ajello et al GRB 190114C in the nuclear region of an interacting galaxy --
A detailed host analysis using ALMA, HST and VLT
~ A. de Ugarte Postigo et al
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Last edited by bystander on Thu Nov 21, 2019 3:44 pm, edited 1 time in total.
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