NASA shows gamma-ray time-lapse of the Milky Way

NASA has published a time-lapse based on data collected by the Fermi Gamma-ray Telescope. It shows the Milky Way.

The Fermi Telescope was launched in 2008. It is located in Earth orbit and is designed to observe large areas of space in the gamma-ray range. With its help, astronomers investigate astrophysical and cosmological processes occurring in active galactic nuclei, pulsars and other high-energy sources, study gamma-ray bursts, search for dark matter, etc.

The time-lapse published by NASA covers 14 years of Fermi observations: from August 2008 to August 2022. The video shows the sky from two different angles. The rectangular view shows a bright streak in the center. This is our Milky Way. Its glow is caused by the collision of cosmic rays with interstellar gas. In addition, the Milky Way is home to a large number of active gamma-ray sources, including neutron stars and supernova remnants.

Bright, rapidly changing sources can be seen above and below the Milky Way band. Most of them are distant galaxies that are better seen from a different perspective centered on the north and south poles of our galaxy. Each of these galaxies, called blazars, contains a supermassive black hole, the accretion disk around which is a source of powerful jets. Fluctuations in their brightness indicate the changes taking place in them. Or, more precisely, what has been happening. Most of these galaxies are located billions of light-years away from Earth.

You can also pay attention to a moving source that crosses the screen along a characteristic trajectory. This is our Sun, whose apparent motion reflects the annual orbital motion of the Earth around it. As a rule, it is not the brightest source of gamma radiation. But when powerful gamma-ray flares occur on the Sun, this temporarily changes.

At the same time, many short-term events that Fermi studies, such as gamma-ray bursts, are not included in the time-lapse. This is due to the peculiarity of the telescope’s data processing.

Based on materials from