Articles tagged with Gamma Ray Astronomy
Astronomers used High Energy Stereoscopic System to observe gamma ray burst GRB 190829A's afterglow, detecting emission at several tera-electronvolts. The results show similar spectral properties and decay profiles to x-ray emission, contradicting current emission models for gamma ray bursts.
Researchers have eliminated dark matter candidates as the origin of excess gamma rays detected in the Milky Way's galaxy center through extensive modeling exercises. The study puts strongest constraints yet on dark matter properties, ruling out weakly interacting massive particles up to very high-mass particles.
Astronomers studied the galaxy's radio structure using VLBA, revealing a striking TIE fighter shape at 6.6 GHz. The team observed two periods of activity in TXS 0128+554, suggesting a lull in activity created a gap in the radio emission.
Researchers at Penn State suggest that supermassive black hole coronae could be the source of high-energy cosmic neutrinos, exceeding expectations. The new model predicts electromagnetic counterparts in soft gamma-rays, with next-generation detectors poised to explore this possibility.
A trio of satellites, including NASA's Fermi and NuSTAR space telescopes, observed a nova outburst in 2018 and captured direct evidence that most of the explosion's visible light arose from shock waves. The data confirmed that shock waves play a major role in powering some stellar explosions.
Researchers confirm Lorentz Invariance holds true at record-breaking high-energy gamma rays, extending the range where relativity's constant speed of light is valid. The High Altitude Water Cherenkov Observatory detected gamma rays from distant galactic sources, providing powerful proof of Einstein's theory.
Researchers have found the first direct correlation between dark matter and gamma rays in the universe. The study used gamma ray data from Fermi Large Area Telescope and mapped it with weak gravitational lensing, providing insights into the nature of dark matter and its potential connection to gamma ray emissions.
Researchers have identified nine galactic sources of super-high-energy gamma rays with energies over 56 trillion electron volts, three of which emit gamma rays extending to 100 TeV and beyond. These discoveries help explain where high-energy particles originate and how they are accelerated.
Researchers discovered a correlation between the unresolved gamma-ray background and matter distribution in the distant universe, suggesting that dark matter could be a source of the faint cosmic glow. The study used data from the Dark Energy Survey and Fermi Gamma-ray Space Telescope to analyze the correlation.
Scientists have detected gamma-rays from two gamma-ray bursts with ground-based telescopes, producing energies up to 100 billion times that of visible light. The observations provide insights into the gigantic explosions and their physical mechanisms.
The detection of record-setting gamma-ray bursts by NASA's Fermi Gamma-ray Space Telescope and Neil Gehrels Swift Observatory has provided new insights into the mechanisms driving these events. The blasts produce an initial pulse of gamma rays, followed by afterglows that can be detected at longer wavelengths.
The Tibet ASgamma experiment has discovered the highest energy gamma rays ever observed from an astrophysical source, exceeding 450 TeV. The most energetic gamma rays were produced by interaction between high-energy electrons and cosmic microwave background radiation.
The catalog includes 17 short and 169 long bursts, providing fresh insights into how gamma-ray bursts work. Astronomers can distinguish the two GRB classes by the duration of their lower-energy gamma rays, revealing clues to the physical mechanisms at play.
Astronomers have discovered a rare gamma-ray binary system, allowing for the study of particle acceleration in a unique environment. The system, consisting of a massive star and a rapidly rotating neutron star, was detected emitting high-energy particles accelerated by its strong magnetic field.
The GRAINE collaboration launched a balloon-borne nuclear emulsion telescope to observe high-energy cosmic gamma rays. The experiment successfully completed a record-long flight of 17 hours and achieved high-resolution observations, marking a significant milestone in the field of cosmic gamma-ray research.
The VERITAS array has confirmed the detection of high-energy gamma rays from a supermassive black hole located in a distant galaxy, TXS 0506+056. This detection is significant as it provides evidence that nearby and faraway galaxies with supermassive blackholes at their centers are actively creating high-energy cosmic rays.
The VERITAS array confirmed detection of gamma rays from a supermassive black hole, potentially the first astrophysical source of high-energy cosmic neutrinos. This discovery may shed light on the acceleration mechanisms that create cosmic rays.
The study using data from NASA's NuSTAR space telescope reveals that Eta Carinae accelerates particles to high energies, some of which may reach Earth as cosmic rays. The team's analysis suggests that the accelerated electrons and other particles are ejected in violent shock waves along the boundary of the colliding stellar winds.
A new theoretical model reveals that these particles originate from accelerated cosmic rays via powerful black-hole jets. The model explains the similar energies of the particles by suggesting they inherit energy from their parent particles.
A combined analysis of NASA's Fermi Gamma-ray Space Telescope and H.E.S.S. data suggests the galactic center contains a high-energy trap that concentrates cosmic rays, mostly protons. This results in a gamma-ray glow extending to the highest energies observed.
The Fermi telescope has observed high-energy light from solar eruptions on the far side of the sun, which should block direct light. This allows scientists to study how charged particles are accelerated to nearly the speed of light during solar flares.
Astronomers discover five new gamma-ray blazars with massive black holes, challenging current ideas on their formation and growth. The discoveries suggest that these objects could have formed rapidly in the universe's early history.
A team of scientists has linked a record-breaking neutrino detected by IceCube to an explosion in the galaxy PKS B1424-418, which was observed in 2012. The researchers calculated a 5-percent probability that the two events were unrelated.
A team of researchers has found evidence for a particle accelerator in the center of the Milky Way that can accelerate protons to petaelectronvolt energies. The discovery sheds new light on the origin of galactic cosmic rays and challenges existing theories.
Researchers found intriguing contradictions between IceCube neutrino data and Fermi gamma-ray data, suggesting 'hidden accelerator' origins of high-energy cosmic neutrinos. Proton-photon interactions may block high-energy gamma rays from escaping, enabling the use of neutrinos as new probes of dense astrophysical environments.
Two studies find gamma ray signals in the galactic center are unlikely caused by dark matter collisions. Instead, they could be attributed to fast-rotating stars called millisecond pulsars. Researchers used statistical analysis methods to analyze images of gamma rays captured by NASA's Fermi Gamma-ray Space Telescope.
The Fermi team has created the most detailed census of the sky yet made at extreme energies using improved data processing methods. The new sky map reveals hundreds of high-energy sources, including blazars and remnants of supernova explosions.
Researchers detected gamma rays from a rare blazar galaxy, PKS 1441+25, 7.6 billion light-years away, setting new bounds on the extragalactic background light. The observations provide clues to the production of high-energy gamma rays and their interaction with the surrounding environment.
Astronomers measured the density of photon fog between Earth and quasar PKS 1441+25 using high-energy gamma rays. The data validated theoretical models for the number and brightness of stars and galaxies in the universe going back 7.6 billion years.
Astronomers observed gamma rays from PKS 1441+25, a blazar galaxy 7 billion years away. The high-energy light revealed a single region far from the power source, contradicting previous assumptions.
The VERITAS telescope detected powerful gamma rays from a distant galaxy, PKS 1441+25, revealing details about the black hole engine at its center. The gamma-ray emission was found to be located within the relativistic jet, but surprisingly far from the black hole, and is estimated to be around 5 light-years away.
A newly discovered dwarf galaxy is radiating high-energy gamma rays, potentially pointing to the presence of dark matter. The detection was made using publicly available data from NASA's Fermi Gamma-ray Space Telescope and has sparked excitement in the scientific community.
A team of researchers, led by Michigan State University astronomer Laura Chomiuk, has discovered the location where a nova explosion emitted gamma rays. Using highly detailed radio telescope images, they pinpointed the source to a stellar explosion, which may be common in other nova explosions.
High-resolution radio-telescope images have revealed the locations where a stellar explosion called a nova emitted gamma rays, a previously mystifying phenomenon. The discovery also provided insights into the probable mechanism of gamma-ray emissions in other nova explosions.
Novae are sudden, short-lived brightenings of stars caused by thermonuclear explosions on white dwarf surfaces. NASA's Fermi Gamma-ray Space Telescope has detected gamma-rays from these events, showing they release up to 100,000 times the annual energy output of the sun.
Researchers used the Fermi Gamma-ray Space Telescope to discover high-energy gamma rays emitted by an exploding star. The surprising finding dispels the notion that classical nova explosions lack the power to produce such radiation.
Astronomers have observed a unique transformation of a binary system containing a rapidly spinning neutron star. The system, known as AY Sextantis, underwent a dramatic change in behavior, with the pulsar's radio beacon vanishing and its gamma-ray emission increasing fivefold.
The team detected a series of bright gamma-ray flares from a source known as B0218+357, located in a gravitational lens system. The gamma-ray delay is about a day longer than radio observations report for this system, and the region emitting gamma rays is very small compared to those emitting at lower energies.
John Hawley and Steven Balbus were recognized for their discovery that magnetic fields make accretion disks unstable, solving a fundamental problem in astrophysics. Their work transformed the field of accretion disk theory and earned them the $1 million Shaw Prize award.
Researchers set lower limit for blazar's redshift, indicating distance of at least 7.4 billion light-years, challenging current models of blazar emission mechanisms and extragalactic background light propagation.
The most distant known source of very high-energy gamma rays, PKS 1424+240, deviates from expected emission spectrum despite being detected at a great distance of over 7.4 billion light-years. The findings may indicate new insights into blazar emission mechanisms or the extragalactic background light.
The Portable Neutron Spectroscope (NSPECT) is a highly sensitive instrument that detects illicit radioactive materials with pinpoint accuracy. The technology, developed by UNH scientists, employs techniques used in NASA's Compton Gamma Ray Observatory to locate nuclear bomb-making material.
The Fermi team has discovered hundreds of new energy sources in the high-energy sky, including active galaxies and pulsars. These discoveries will allow astronomers to compare the behavior of different sources across a wider span of gamma-ray energies for the first time.
Scientists use NASA's Fermi Gamma-Ray Space Telescope to detect high-energy gamma rays from the remnant of Tycho's supernova. This detection supports the notion that supernova remnants can accelerate cosmic rays, providing clues to their origins.
Researchers have discovered gamma rays with unprecedented energies from the Crab Pulsar in the Crab Nebula, contradicting existing theories. The findings suggest a different mechanism for producing these high-energy particles, which could be detected by the VERITAS observatory.
Researchers used the $20 million VERITAS telescope to discover pulsed gamma rays exceeding energies of 100 billion electron volts, a surprise given previous detection limits were at 25 billion eV. The findings indicate a need for new ideas about pulsars and their gamma-ray production.
A NASA team will attempt to send a balloon with an instrument payload to measure gamma rays from the Crab Pulsar, 6,500 light years away. The mission aims to study the polarization of gamma rays, which can provide clues about the source's mechanism.
Integral's observations show that quantum 'graininess' must be at much smaller scales than previously predicted, contradicting Einstein's General Theory of Relativity. The results limit the size of these grains to 10^-48 m or smaller, ruling out some string theories and quantum loop gravity theories.
A team of astronomers using NASA's Fermi Gamma-ray Space Telescope observed a unique binary system that produced dual gamma-ray flares during its closest approach. The flares were many times stronger than expected and occurred despite the star following an eccentric orbit, making them only visible every 3.4 years.
A collaboration between CSIRO and NASA has tracked down 25 ultrafast 'millisecond' pulsars in just two years, revealing insights into the physics of these small spinning stars. The research uses a combination of land- and space-based detectors to understand how pulsars make their beams of radiation.
The telescope discovered two gamma-ray-emitting bubbles that span 50,000 light-years north and south of the galactic center
Astronomers used the Fermi Gamma-ray Space Telescope to map gamma rays emitted by Centaurus A, a galaxy with a supersized black hole. The discovery confirms that microwave photons can be accelerated to gamma-ray energies through inverse Compton scattering.
Astronomers using NASA's Fermi Gamma-ray Space Telescope found that less than a third of gamma-ray emission arises from black-hole-powered jets. The study suggests that alternative explanations, such as particle acceleration in normal star-forming galaxies and dark matter, may be responsible for the extragalactic gamma-ray background.
Researchers have detected gamma rays of a trillion electron volts coming from the M 82 galaxy, providing evidence for a strong connection between galaxies with high star formation and the production of cosmic rays. The discovery uses the VERITAS array of four telescopes at the Fred Lawrence Whipple Observatory in Arizona.
The Fermi telescope has mapped over 1,000 discrete sources of gamma rays, exceeding previous knowledge. It has also detected a short gamma ray burst, eliminating approaches to new theories of gravity that predict energy-dependent changes in the speed of light.
The NASA Fermi Gamma-ray Space Telescope has discovered a third class of active galaxies that emit gamma rays, opening a new window in the field. The telescope has detected gamma rays from dozens of galaxies beyond our own, including Seyfert galaxies and blazars.
Astronomers analyzed gamma-rays from two dozen pulsars, including 16 discovered by Fermi, revealing unprecedented power for discovering and studying gamma-ray pulsars. The studies shed light on the nature of unidentified gamma-ray sources in our galaxy.
Researchers have located the site of relativistic particle acceleration in galaxy M 87, where particles are accelerated to extreme energies and emit gamma rays with trillion-electron Volt energies. The discovery was made possible by combining high-resolution radio and gamma-ray observations using three arrays of telescopes.
Using a worldwide VLBA collaboration, scientists pinpoint the origin of superenergetic gamma rays coming from M87's core near the supermassive black hole. The discovery sheds light on the mechanisms powering galaxies' energetic jets.
The Fermi telescope captured a hypnotic froth of gamma rays, revealing active galaxies called blazars flare up and fade out. The movie shows the entire sky as northern and southern halves, with bright colors indicating greater numbers of detected gamma rays.