The discovery of large-scale features in the gamma-ray sky in approximately the same direction continues to puzzle researchers.
Gravity behaves the same way on a galactic scale as it does in our solar system, and alternative gravity models which remove the need for dark energy are disfavoured.
NASA’s Chandra X-ray Observatory have revealed a dozen stellar-mass black holes at the centre of the galaxy, providing the first observational evidence for such a black-hole cluster.
To celebrate its 15th anniversary, the HESS collaboration has published its largest set of scientific results to date.
Adam Riess from the Space Telescope Science Institute and colleagues have now made a more precise, direct measurement that reinforces the mismatch and could signal new physics.
Radiation emitted around a distant black hole has revealed the existence of extragalactic planets in a galaxy 3.8 billion light years away.
Multi-messenger astronomy, neutrino physics and dark matter are among several topics set to take priority in Europe, according to a report by the Astroparticle Physics European Consortium (APPEC).
A new national facility at La Silla Observatory in Chile, operated by the European Southern Observatory (ESO), made its first observations at the beginning of the year.
The spectrum of J1342+0928 gives us a view on the universe when it was just 690 million years old.
New measurements by the High-Altitude Water Cherenkov (HAWC) experiment hints at a more exotic origin of the positron excess.