Images by Date
Images by Category
Solar System
Stars
White Dwarfs
Supernovas
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Quasars
Galaxy Clusters
Cosmology/Deep Field
Miscellaneous
Images by Interest
Space Scoop for Kids
4K JPG
Multiwavelength
Sky Map
Constellations
3D Wall
Photo Blog
Top Rated Images
Image Handouts
Desktops
High Res Prints
Fits Files
Image Tutorials
Photo Album Tutorial
False Color
Cosmic Distance
Look-Back Time
Scale & Distance
Angular Measurement
Images & Processing
AVM/Metadata
Getting Hard Copies
Image Use Policy
Web Shortcuts
Chandra Blog
RSS Feed
Chronicle
Email Newsletter
News & Noteworthy
Image Use Policy
Questions & Answers
Glossary of Terms
Download Guide
Get Adobe Reader
Where is the Universe Hiding its Missing Mass? Animations
A Tour of Where is the Universe Hiding its Missing Mass?
(Credit: NASA/CXC/A. Hobart)
[Runtime: 03:09]

With closed-captions (at YouTube)

Astronomers have spent decades looking for something that sounds like it would be hard to miss: about a third of the "normal" matter in the Universe. New results from NASA's Chandra X-ray Observatory may have helped them locate this elusive expanse of missing matter.

From independent, well-established observations, scientists have confidently calculated how much normal matter — meaning hydrogen, helium and other elements — existed soon after the Big Bang. In the time between the first few minutes and the first billion years or so, much of the normal matter made its way into gas and objects such as stars and planets, observed in the present-day Universe.

The problem is that when astronomers add up the mass of all the normal matter in the present-day Universe about a third of it can't be found. (This missing matter is distinct from the still-mysterious dark matter.)

One idea is that the missing mass gathered into gigantic strands or filaments of warm (that is, temperature less than 100,000 Kelvin) gas and hot (as in hotter than 100,000 Kelvin) gas in intergalactic space. These filaments are known by astronomers as the "warm-hot intergalactic medium" or WHIM. They are invisible to optical light telescopes, but some of the warm gas in filaments has been detected in ultraviolet light.

Using a new technique, researchers have found new and strong evidence for the hot component of the WHIM based on data from Chandra and other telescopes. They used Chandra to look for and study filaments of warm gas lying along the path to a quasar, a bright source of X-rays powered by a rapidly growing supermassive black hole. This quasar is located about 3.4 billion light years from Earth.

Their work revealed an absorption line from oxygen expected to be present in a gas with a temperature of about one million Kelvin. By extrapolating from these observations of oxygen to the full set of elements, and from the observed region to the local Universe, the researchers report they can account for the complete amount of missing matter.

If this result is confirmed, one of the biggest puzzles in modern astrophysics could be solved.


A Quick Look at Where is the Universe Hiding its Missing Mass?
(Credit: NASA/CXC/A. Hobart)
[Runtime: 1:08]

The Universe has a problem — or at least the astronomers who study it do.

Scientists cannot account for about a third of the "normal" matter that they think was created shortly after the Big Bang.

Normal matter includes hydrogen, helium, and other elements that make up everything from planets to stars to galaxies (but not dark matter).

One place this "missing mass" might have ended up is giant strands of superheated gas known by astronomers as the WHIM.

A team of researchers has used data from NASA's Chandra X-ray Observatory to look for signatures of the WHIM in X-rays from a distant quasar.

Their work, which uses a new technique, suggests that they have found evidence for multiple pieces of the WHIM.

If this result is confirmed by other observations, a long-standing mystery in astrophysics could be finally solved.




Return to Where is the Universe Hiding its Missing Mass? (February 14, 2019)