new movies from NASA's Fermi mission shows the intensity of gamma rays, the highest energy form of light, with energies of over 200 million electron volts (MeV), detected by Fermi's Large Area Telescope between August 2008 and August 2022 . For comparison, visible light has an energy of 2 to 3 electrons. bolt. Lighter colors indicate the location of more intense gamma ray sources.
“The Milky Way's bright, steady gamma-ray glow is punctuated by intense flares of near-light-speed jets that last for days, powered by the supermassive black hole at the center of the distant galaxy.” Dr. Digel said. Staff Scientist at SLAC National Accelerator Laboratory.
“These dramatic eruptions can appear anywhere in the sky, occurred millions to billions of years ago, and their light is just reaching Fermi as we see it. ”
“The first thing you see in a movie is a steady arc of light across the screen,” said Dr. Judy Racusin, a research scientist at NASA's Goddard Space Flight Center.
“It's our sun, and its apparent motion reflects the Earth's annual orbital motion.”
Most of the time, Fermi's Large Area Telescope (LAT) picks up faint glimpses of the Sun due to the influence of accelerated particles called cosmic rays. When they come into contact with the sun's gases or the light it emits, gamma rays are produced.
But sometimes, the sun suddenly brightens up in a powerful eruption called a solar flare, temporarily making our star one of the brightest sources of gamma rays in the sky.
The Fermi team created an all-sky time-lapse movie using 14 years of data acquired by Fermi's large-area telescope. Image credit: NASA Goddard Space Flight Center/DOE/LAT Collaboration.
“The new film depicts the sky from two different perspectives,” the astronomers said.
“The rectangular view shows the entire sky with the galaxy's center in the middle.”
“This highlights the central plane of the Milky Way, which glows with gamma rays produced from cosmic rays striking interstellar gas and starlight.”
“Many other sources are also scattered, such as neutron stars and supernova remnants.”
“Above and beyond this central band, we look out beyond our galaxy and into a wider universe studded with bright, rapidly changing light sources.”
“Most of these are actually distant galaxies that are better seen from a different perspective, centered around our galaxy's north and south poles.”
“Each of these galaxies, called blazars, has a central black hole with the mass of more than a million suns.”
“Somehow, black holes produce jets of matter that move at very high speeds. Using a blazar, we can see one of these jets almost directly below us, enhancing their brightness and variability. Masu.”
“This fluctuation indicates that something has changed in these jets,” Dr. Raksin said.
“We monitor these sources regularly and alert other telescopes, both in space and on the ground, when something interesting is happening.”
“We need to catch these flares quickly before they disappear, and the more observations we can collect, the better we can understand these events.”
Fermi plays a key role in a growing network of missions working together to capture these changes as they unfold in space.
“Many of these galaxies are very distant,” the researchers said.
“For example, the light from the blazar known as 4C +21.35 has been traveling for 4.6 billion years. This means that the flare-ups we see today actually happened when the sun and solar system began to form. means.”
“Other bright blazars are more than twice as far away, providing an impressive snapshot of black hole activity across cosmic time.”
“Many short-lived events that Fermi studies, such as gamma-ray bursts, the most powerful cosmic explosions, cannot be seen in time-lapse.”
“This is the result of processing data over several days to sharpen the image.”
Source: www.sci.news
