The MUSE instrument on ESO's Very Large Telescope in Chile has revealed very detailed haloes of neutral hydrogen around distant galaxies. A new result zooms on a few such haloes, one of them forming a large, almost complete ring of light.

This result will be presented by Adelaide Claeyssens (Centre de Recherche Astrophysique de Lyon) at the annual meeting of the European Astronomical Society (EWASS 2019) in Lyon, France, on 25 June.

Galaxies are surrounded by copious amounts of neutral hydrogen in a region extending very far away from their center. This region is very important as it is the location of the exchanges of gas between galaxies and their environment, and a key element to understand galaxy formation and evolution. In distant galaxies, this region can be revealed through the glow of the gas emission in a halo.

The MUSE instrument, in operation on the Very Large Telescope of the European Southern Observatory, is extremely efficient at identifying haloes around almost all distant galaxies it observed, but they are generally too small to show any detail or structure. The new study combined the power of MUSE with the so-called gravitational lensing effect of galaxy clusters.

Adelaide Claeyssens explains: "Indeed, massive clusters have the property to bend light rays passing through their center, as predicted by Einstein. This produces the effect of a magnifying glass: the images of background galaxies are magnified."

The study presents the two most spectacular observations of magnified haloes obtained to date with MUSE; in one case the halo presents the form of a large, almost complete ring of light.

By zooming on such hydrogen haloes surrounding galaxies, it is possible for the first time to study with unprecedented detail how the gas properties vary across the halo. This information is critical for understanding the physical processes at play in the halo, that is, how homogeneous it is and how the gas moves around the galaxy.

This discovery demonstrates the potential of MUSE combined with the lensing effects to study many more such haloes and to acquire a detailed view about galaxy formation in the universe, when it was only a few billion years old.

Related Links
MUSE
Understanding Time and Space

Tweet

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

Clocks, gravity, and the limits of relativity
Paris (ESA) May 27, 2019
The International Space Station will host the most precise clocks ever to leave Earth. Accurate to a second in 300 million years the clocks will push the measurement of time to test the limits of the theory of relativity and our understanding of gravity. Albert Einstein's general theory of relativity predicted that gravity and speed influences time, the faster you travel the more time slows down, but also the more gravity pulling on you the more time slows down. On 29 May 1919 Einstein's the ... read more