Astrophysics and cosmology Archives – Page 40 of 58

Swift catches afterglows of gamma-ray bursts

The ability of NASA’s Swift satellite to point its X-ray telescope rapidly towards gamma-ray bursts is, for the first time, allowing the study of the afterglow phase a minute or so after the act...

Foundations of Modern Cosmology (Second Edition)

The new edition of this thorough, descriptive introduction to the physical basis for modern cosmological theory includes the latest observational results and provides the background material necessary...

Astronomers discover possible 10th planet

A planet larger than Pluto has been discovered orbiting the Sun at more than three times the current distance from the Sun to Pluto. It is a clear member of the Kuiper belt of objects beyond the orbit...

Theory demystifies supermassive black holes

The existence of powerful quasars at high redshift raises the question of the rapid formation of supermassive black holes. How could early black holes accrete 1 billion solar masses in less than 1 bil...

Giant flare illuminates the Earth

On 27 December 2004, one day after the devastating tsunami in the Indian Ocean, the Earth was illuminated by the biggest splash of light ever recorded from outside the solar system. For 0.2 s, th...

HESS detects mysterious high-energy sources in the Milky Way

The first detailed image of the central part of our galaxy at very-high-energy gamma rays shows several sources.

Radio astronomers observe a possible dark-matter galaxy

An international team of astronomers has discovered what appears to be an invisible galaxy made almost entirely of dark matter – the first ever detected. The mystery galaxy, VIRGOHI21, lies in t...

Very High Energy Cosmic Gamma Radiation: A Crucial Window on the Extreme Universe

Marc Türler reviews in 2005 Very High Energy Cosmic Gamma Radiation: A Crucial Window on the Extreme Universe.

Missing baryons found in hot gas

While it is well known that ordinary baryonic matter constitutes only about 5% of the total energy content of the universe, it is probably less commonly appreciated that about half of this “know...