Quasars

Tracing 13 billion years of history by the light of ancient quasars

Published on 08/03/2023

An internation team of astrophysicists (including IoA Professor Martin Haehnelt) have shed new light on the state of the universe 13 billion years ago by

Variations in the ‘fogginess’ of the universe identify a milestone in cosmic history

Published on 15/04/2019

Large differences in the ‘fogginess’ of the early universe were caused by islands of cold gas left behind when the universe heated up after the big bang, according to an international team of astronomers.

Accretion onto Compact Objects

A major area of research in X-ray astronomy is the accretion of matter on to black holes and neutron stars in the context of AGN and galactic X-ray binaries. Accretion is an energetic process and can give high luminosities.

Cosmic Reionisation

During the epoch of reionization the first stars and black holes in the Universe (re-) ionized the Intergalactic Medium. Studying the epoch of reionization will tell us about the first galaxies.

First Quasars

Observations of nearby galaxies and high-redshift quasars suggest that black holes are present in the majority of galaxies. The first quasars harbor already black holes as massive as several billion solar masses.

Quasars and active galaxies

Quasars are the most luminous objects in the Universe and powered by accreting supermassive black holes in the centres of galaxies.

Intergalactic Medium at High Redshift

The intergalactic medium (IGM) and not galaxies contain most of the baryons (e.g. H, He, C, N, O) in the Universe. We use spectroscopic observations of high redshift backgound quasars to study this material.

X-ray Group

X-ray astronomy research in Cambridge is carried out by an active X-ray Astronomy group whose research focusses on accretion on to compact objects and the physics of clusters of galaxies.