The trick works because galaxies, and the wider intergalactic medium
, contain a lot of neutral hydrogen gas.
We usually view that as the time of little galaxies working hard to chew away at the neutral intergalactic medium
Previous studies have shown that around 10% of all quasars examined were surrounded by halos, made from gas known as the intergalactic medium
Five lectures from the course cover re-ionization of the intergalactic medium
, weak gravitational lensing, large-scale structure observations, galaxy formation, and cosmology from theory to data and from data to theory.
The ultraluminous nature of this quasar will allow us to make unprecedented measurements of the temperature, ionization state and metal content of the intergalactic medium
at the epoch of reionization.
In the past decade, supercomputer simulations of galaxy formation have become so sophisticated that they can actually predict how galaxies form and are fed: gas funnels onto galaxies along thin "cold streams" which, like streams of snow melt feeding a mountain lake, channel cool gas from the surrounding intergalactic medium
onto galaxies, continuously topping up their supplies of raw material for star formation.
The study, published online April 1 in Science, "may be a clue that there was some fundamental process in the intergalactic medium
that made magnetic fields," says Ellen Zweibel, an astrophysicist at the University of Wisconsin-Madison, who was not associated with the work.
The Cosmic Microwave Background Radiation (CMBR) has been shown by others to be a result of absorption and scattering of the intergalactic medium
The 13 contributions in the 2007 edition of this annual series summarize recent development in understanding star formation, irregular planetary satellites, and the intergalactic medium
in rich clusters of galaxies.
The intergalactic medium
(IGM) fills up those massive voids, but the sparse nature of this rarified plasma means it emits very little light and is therefore difficult to study.
These stars' thick coronas could pack electrons tightly enough to have the same effect on passing radio waves as billions of light-years of the mostly empty intergalactic medium