Fermi tagged posts

Discovery of van Hove Singularities could Lead to Novel Materials with Desirable Quantum Properties

Discovery could lead to novel materials with desirable quantum properties
The electronic topology in the chiral fermion conductors RhSi and CoSi. Credit: Nature Physics (2023). DOI: 10.1038/s41567-022-01892-6

Strong interactions between subatomic particles like electrons occur when they are at a specific energy level known as the van Hove singularity. These interactions give rise to unusual properties in quantum materials, such as superconductivity at high temperatures, potentially ushering in exciting technologies of tomorrow.

Research suggests topological materials that allow electrons to flow only on their surface to be promising quantum materials. However, the quantum properties of these materials remain relatively unexplored.

A study co-led by Nanyang Asst Prof Chang Guoqing of NTU’s School of Physical and Mathematical Sciences identified two ty...

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Astronomers Discover Heavy Elements after Bright Gamma-Ray Burst from Neutron Star Merger

An artist illustration of a merger of two neutron stars that create heavy elements.
Illustration courtesy of Luciano Rezzolla, University of Frankfurt, Germany

Breakthrough discovery puts astronomers one step closer to solving the mystery of the origin of elements that are heavier than iron. An international team of astronomers — including Clemson University astrophysicist Dieter Hartmann — obtained observational evidence for the creation of rare heavy elements in the aftermath of a cataclysmic explosion triggered by the merger of two neutron stars.

The massive explosion unleashed a gamma-ray burst, GRB230307A, the second brightest in 50 years of observations and about 1,000 times brighter than a typical gamma-ray burst. GRB230307A was first detected by NASA’s Fermi Gamma-Ray Space Telescope on March 7, 2023.

Using multiple space- and ground-based telescopes, in...

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A Gamma-Ray Pulsar Milestone Inspires Innovative Astrophysics and Applications

The U.S. Naval Research Laboratory (NRL), in conjunction with the international Fermi Large Area Telescope Collaboration, announce the discovery of nearly 300 gamma ray pulsars in the publication of their Third Catalog of Gamma Ray Pulsars. This milestone comes 15 years since the launch of Fermi in 2008, when there were fewer than ten known gamma-ray pulsars.

“Work on this important catalog has been going on in our group for years,” said Paul Ray, Ph.D., head of the High Energy Astrophysics and Applications Section at NRL.

“Our scientists and postdocs have been able to both discover and analyze the timing behavior and spectra of many of these newfound pulsars as part of our quest to further our understanding of these exotic stars that we are able to use as cosmic clocks.”

Pul...

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NASA’s Fermi Detects First Gamma-Ray Eclipses from ‘Spider’ Star Systems

Streams of material blow off an orange-yellow in the foreground. In the distance, a pulsar rotates like a lighthouse, emitting beams of magenta light. The background is black, purple, and speckled with stars.
An orbiting star begins to eclipse its partner, a rapidly rotating, superdense stellar remnant called a pulsar, in this illustration. The pulsar emits multiwavelength beams of light that rotate in and out of view and produces outflows that heat the star’s facing side, blowing away material and eroding its partner.
Credits: NASA/Sonoma State University, Aurore Simonnet

Scientists have discovered the first gamma-ray eclipses from a special type of binary star system using data from NASA’s Fermi Gamma-ray Space Telescope. These so-called spider systems each contain a pulsar—the superdense, rapidly rotating remains of a star that exploded in a supernova—that slowly erodes its companion.

An international team of scientists scoured over a decade of Fermi observations to find seven sp...

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