blazars – Astronomy Now

Counting all the photons in the universe (spoiler alert: it’s a big number)

3 December 2018 Astronomy Now

Studying interactions between extragalactic light and gamma rays emitted by blazars has allowed astronomers to calculate how much light has been emitted across the age of the cosmos.

NASA’s Fermi discovers the most extreme blazars yet

31 January 2017 Stephen Clark

NASA’s Fermi Gamma-ray Space Telescope has identified the farthest gamma-ray blazars, a type of galaxy whose intense emissions are powered by supersized black holes. Light from the most distant object began its journey to us when the universe was 1.4 billion years old, or nearly 10 percent of its present age.

NASA space observatories reveal surprising monster black hole connection

30 August 2016 Astronomy Now

Astronomers studying distant galaxies powered by monster black holes have uncovered an unexpected link between two very different wavelengths of the light they emit, the mid-infrared and gamma rays.

Fermi space telescope expands its search for dark matter

14 August 2016 Astronomy Now

Dark matter, the mysterious substance that constitutes most of the material universe, remains as elusive as ever. Although experiments on the ground and in space have yet to find a trace of dark matter, six or more years of data from NASA’s Fermi Gamma-ray Space Telescope has broadened the mission’s dark matter hunt using some novel approaches.

X-ray echoes of a shredded star provide close-up of monster black hole

23 June 2016 Astronomy Now

Some 3.9 billion years ago in the heart of a distant galaxy, the intense tidal pull of a monster black hole shredded a star that passed too close. After X-rays produced in this event first reached Earth on 28 March 2011, scientists concluded that the outburst, now known as Swift J1644+57, also represented the sudden flare-up of a previously inactive black hole.