A Giant Gamma-Ray Bubble is a Source of Extreme Cosmic Rays

An artist's depiction of a gamma-ray burst's relativistic jet full of very-high-energy photons breaking out of a collapsing star. Credit: DESY, Science Communication Lab

Gamma-ray bursts (GRBs) are one of the most powerful phenomena in the Universe and something that astronomers have been studying furiously to learn more about their origins. In recent years, astronomers have set new records for the most powerful GRB ever observed – this includes GRB 190114C, observed by the Hubble Space Telescope in 2019, and GRB 221009A, detected by the Gemini South telescope in 2022. The same is true for high-energy cosmic rays that originate from within the Milky Way, whose origins are still not fully understood.

In a recent study, members of China’s Large High Altitude Air Shower Observatory (LHAASO) Collaboration discovered a massive gamma-ray burst (designated GRB 221009A) in the Cygnus star-forming region that was more powerful than 10 peta-electronvolts (PeV, 1PeV=1015eV), over ten times the average. In addition to being the brightest GRB studied to date, the team was able to precisely measure the energy spectrum of the burst, making this the first time astronomers have traced cosmic rays with this energy level back to their source.

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Astronomers Scan the Skies for Nanosecond Pulses of Light From Interstellar Civilizations

Artist’s impression of Green Bank Telescope connected to a machine learning network. Credit: Breakthrough Listen/Danielle Futselaar.

In 2015, Russian-Israeli billionaire Yuri Milner and his non-profit organization, Breakthrough Initiatives, launched the largest Search for Extraterrestrial Intelligence (SETI) project. Known as Breakthrough Listen, this SETI effort relies on the most powerful radio telescopes in the world and advanced analytics to search for potential evidence of technological activity (aka. “technosignatures”). The ten-year project will survey the one million stars closest to Earth, the center of our galaxy, the entire galactic plane, and the 100 galaxies closest to the Milky Way.

In 2018, they partnered with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) Collaboration, a ground-based system of gamma-ray telescopes operating at the Fred Lawrence Whipple Observatory (FLWO) atop Mt. Hopkins in southern Arizona. In a recent paper, the VERITAS Collaboration shared the results of the first year of their search for “optical technosignatures” (from 2019 to 2020). Their results are a vital proof of concept demonstrating how future searches for extraterrestrial civilizations can incorporate optical pulses into their technosignature catalog.

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The Universe Sparkles in Gamma Rays in this New NASA Animation

Cosmic fireworks, invisible to our eyes, fill the night sky. We can get a glimpse of this elusive light show thanks to the Large Area Telescope (LAT) aboard NASA’s Fermi Gamma-ray Space Telescope, which observes the sky in gamma rays, the highest-energy form of light. Image Credit: NASA’s Marshall Space Flight Center/Daniel Kocevski

We’ve come a long way since gamma rays were discovered.

The late 1800s and early 1900s were a time of great scientific advancements. Scientists were just getting a handle on the different types of radiation. Radium featured prominently in the experiments, including one by French scientist Paul Ulrich Villard in 1900.

Radium decays readily, and scientists had already identified alpha and beta radiation coming from radium samples. But Villard was able to identify a third type of penetrating radiation so powerful even a layer of lead couldn’t stop it: gamma rays.

Now we have a gamma ray detector in space, and it’s showing us how the Universe sparkles with this powerful energy.

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Meteorites Bathed in Gamma Rays Produce More Amino Acids and Could Have Helped Life get Going on Earth

Carbonaceous chondrites like the Allende meteorite contain significant amounts of water and amino acids. Could they have delivered amino acids to early Earth and spurred on the development of life? Image Credit: By Shiny Things - originally posted to Flickr as AMNH - Meteorite, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=4196153

Our modern telescopes are more powerful than their predecessors, and our research is more focused than ever. We keep discovering new things about the Solar System and finding answers to long-standing questions. But one of the big questions we still don’t have an answer for is: ‘How did life on Earth begin?’

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Gamma ray Telescopes Might be Able to Detect the Gravitational Waves Caused by Merging Supermassive Black Holes

Gamma rays could be the new source for observing gravitational waves, according to a recent release from the Max Planck Institute for Radio Astronomy. This would make a possible third way to observe gravitational waves including laser interferometry and radio waves.

In 1916 Einstein predicted the existence of gravitational waves, ripples in space-time moving out in all directions away from massive accelerating objects. According to his theory, these waves would travel at the speed of light and would carry with them information about where they came from and would allow us to learn more about gravity.

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Even the Quiet Supermassive Black Holes are Blasting out Neutrinos and Gamma Rays

blazar

Is there anywhere in the Universe where we can escape from radiation? Certainly not here on Earth. And not in space itself, which is filled with diffuse radiation in the form of gamma rays and neutrinos. Scientists have struggled to explain where all those gamma rays and neutrinos come from. A trio of researchers is proposing a source for all that radiation in a new paper: resting black holes.

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Finally an Answer to why Gamma Rays are Coming From Seemingly Empty Space

The cosmic glow of the gamma ray background. Credit: NASA/DOE/Fermi LAT Collaboration

Gamma rays strike Earth from all directions of the sky. Our planet is bathed in a diffuse glow of high-energy photons. It doesn’t affect us much, and we don’t really notice it, because our atmosphere is very good at absorbing gamma rays. It’s so good that we didn’t notice cosmic gamma rays until the 1960s when gamma-ray detectors were launched into space to look for signs of atomic weapons tests. Even then, what we noticed were intense flashes of gamma rays known as gamma ray bursts.

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Astronomers Locate the Source of High-Energy Cosmic Rays

Artist's impression of a supernova. Credit: NASA

Roughly a century ago, scientists began to realize that some of the radiation we detect in Earth’s atmosphere is not local in origin. This eventually gave rise to the discovery of cosmic rays, high-energy protons and atomic nuclei that have been stripped of their electrons and accelerated to relativistic speeds (close to the speed of light). However, there are still several mysteries surrounding this strange (and potentially lethal) phenomenon.

This includes questions about their origins and how the main component of cosmic rays (protons) are accelerated to such high velocity. Thanks to new research led by the University of Nagoya, scientists have quantified the amount of cosmic rays produced in a supernova remnant for the first time. This research has helped resolve a 100-year mystery and is a major step towards determining precisely where cosmic rays come from.

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Jupiter Could Make an Ideal Dark Matter Detector

NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill (wikimedia commons)

So, you want to find dark matter, but you don’t know where to look? A giant planet might be exactly the kind of particle detector you need! Luckily, our solar system just happens to have a couple of them available, and the biggest and closest is Jupiter. Researchers Rebecca Leane (Stanford) and Tim Linden (Stockholm) released a paper this week describing how the gas giant just might hold the key to finding the elusive dark matter.

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Is Dark Matter Responsible for Extra Gamma Rays Coming From the Center of the Milky Way?

A Brilliant Star in Milky Way's Core
A Brilliant Star in Milky Way's Core

For years astronomers have puzzled over a strange excess of gamma rays coming from the galactic center. Annihilating dark matter has always been a tantalizing explanation, and new research claims that it’s the best answer.

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