Astronomers find evidence of atmosphere-like envelopes around galaxies

galaxy
Credit: CC0 Public Domain

A new study by researchers at the University of Hertfordshire, published today in journal Astronomy and Astrophysics, has found evidence that the gaseous envelopes around larger galaxies are similar to the state of Earth's atmosphere.

The study suggests that the gaseous envelopes around that are between a billion and a trillion times the mass of the Sun are in a state of hydrostatic equilibrium. This means these 'envelopes' are stable due the balance between the inward force of gravity and the outward pressure of the gas, which is very similar to the state of Earth's atmosphere.

Galaxies are believed to be surrounded by very tenuous gas that hardly emits any light. Only in the most massive galaxies has any emission of this gas been detected so far. The researchers probed the nature of the gas envelopes by observing jets from the central black holes in the galaxies that light up at , which are brighter if the density in the gaseous envelope is higher.

In particular, the team observed that the gas envelopes of galaxies become increasingly denser around a galaxy mass of 100 billion times the mass of the Sun, leading to a strong increase of radio luminosity for galaxies that exceed this mass.

The was gathered by the LOFAR radio telescope, which is one of the new generation of telescopes that is very sensitive and can see a large part of the sky at once.


Explore further

Astronomers report the most distant radio galaxy ever discovered

More information: Krause, M. G. H., et al. (Accepted/In press). Probing gaseous halos of galaxies with radio jets. Astronomy & Astrophysics. researchprofiles.herts.ac.uk/p … 87d081b)/export.html
Journal information: Astronomy and Astrophysics

Citation: Astronomers find evidence of atmosphere-like envelopes around galaxies (2019, July 11) retrieved 20 October 2019 from https://phys.org/news/2019-07-astronomers-evidence-atmosphere-like-envelopes-galaxies.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Jul 11, 2019
There are some very complicated issues of galaxy formation. Unfortunately, here is the same problem as with the stars. The origin of galaxies remains unclear, in spite of huge activity in the field. What the "formation" means? It means that we have the material that is assembling into galaxies.
https://www.acade...ome_From
https://www.acade...rvations

Jul 13, 2019
So, no surprises. But neat to know.

Jul 14, 2019
Astronomers find evidence of atmosphere-like envelopes around galaxies

It's what plasmas do, they isolate themselves from the surrounding plasma.

Jul 14, 2019
So, no surprises. But neat to know.
.....when you read the article, it was no surprise, you a big DM aficionado? torbjorn_b_g_larsson you were in fact apoplectic when you read this, on the verge of panic for fear of more SCIENCE like this will be crowding even more dark matter further & further to some distant corner of the Universe where it will die an unheralded silent death, as it should.


yep
Jul 22, 2019
Torbs brain is so massive it even knows what it doesn't know.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more