Distant quasar helps to analyze light in universe

	With its 17-m diameter reflector, MAGIC is currently the largest gamma-ray telescope world-wide. Click here for more information.

Observations of the star-like center of a distant galaxy, radiating enormous amounts of energy and more than five billion light-years away from Earth, imply that recent surveys of the number of stars and galaxies in the universe have been accurate, researchers report in the June 26 issue of Science. The intense gamma-rays emitted by this rare celestial event, known as a quasar, mix with background light from other stars and galaxies that influences the light spectrum seen from Earth. Researchers at the MAGIC Collaboration on the Canary Island of La Palma, have used MAGIC, the world’s largest single-dish gamma-ray telescope, to analyze the gamma-rays emitted from the quasar along with the interfering background light. Their findings suggest that earlier observations and measurements from the Hubble Space Telescope and Spitzer Telescope correctly estimate most of the light sources in the universe, and also demonstrate the successful use of cosmic gamma-rays to test these estimates.

ARTICLE #10: "Very-High-Energy Gamma-Rays from a Distant Quasar: How Transparent Is the Universe?," by The MAGIC Collaboration.