Featured Research

from universities, journals, and other organizations

Lost And Found: Hubble Finds Much Of The Universe's Missing Hydrogen

Date:
May 4, 2000
Source:
Space Telescope Science Institute
Summary:
For the past decade astronomers have looked for vast quantities of hydrogen that were cooked-up in the Big Bang but somehow managed to disappear into the empty blackness of space. Now, NASA's Hubble Space Telescope has uncovered this long-sought missing hydrogen. It accounts for nearly half of the "normal" matter in the universe -- the rest is locked up in myriad galaxies.

For the past decade astronomers have looked for vast quantities of hydrogen that were cooked-up in the Big Bang but somehow managed to disappear into the empty blackness of space.

Now, NASA's Hubble Space Telescope has uncovered this long-sought missing hydrogen. It accounts for nearly half of the "normal" matter in the universe -- the rest is locked up in myriad galaxies.

Astronomers believe at least 90 percent of the matter in the universe is hidden in exotic "dark" form that has not yet been seen directly. But more embarrassing is that, until now, they have not been able to see most of the universe's ordinary, or baryonic, matter (normal protons, electrons and neutrons).

The confirmation of this missing hydrogen will shed new light on the large-scale structure of the universe. The detection also confirms fundamental models of how much hydrogen was manufactured in the first few minutes of the universe's birth in the Big Bang.

"This is a successful, fundamental test of cosmological models," said Todd Tripp of Princeton University, Princeton, NJ. "This provides strong evidence that the models are on the right track." The results of Tripp and his collaborators, Edward Jenkins from Princeton and Blair Savage from the University of Wisconsin-Madison, are being published in the May 1 issue of the Astrophysical Journal Letters.

Previous observations show that billions of years ago this missing matter formed vast complexes of hydrogen clouds -- but since then has vanished. Even Hubble's keen eye didn't see the hydrogen directly because it is too hot and rarified. Instead, Hubble found a telltale elemental tracer -- highly ionized (energized) oxygen -- between galaxies, which the hydrogen heats to the temperatures observed in intergalactic space. The presence of highly ionized oxygen between the galaxies implies there are huge quantities of hydrogen in the universe, which is so hot it escapes detection by normal observational techniques.

In recent years, supercomputer models of the expanding, evolving universe have predicted an intricate web of gas filaments where hydrogen is concentrated along vast chain-like structures. Clusters of galaxies form where the filaments intersect. The models predict that vast hydrogen clouds flowing along the chains should collide and heat up. This would squelch the formation of more galaxies in the hottest regions, so star birth was more abundant in the early universe when the hydrogen was cool enough to coalesce.

The oxygen "tracer" was probably created when exploding stars in galaxies spewed the oxygen (created in their cores through nuclear fusion) back into intergalactic space where it mixed with the hydrogen and then was shocked and heated to temperatures over 360,000 degrees Fahrenheit (100,000 degrees Kelvin).

Astronomers detected the highly ionized oxygen by using the light of a distant quasar to probe the invisible space between the galaxies, like shining a flashlight beam through a fog. Hubble's Space Telescope Imaging Spectrograph found the spectral "fingerprints" of intervening oxygen superimposed on the quasar's light. Slicing across billions of light-years of space, the quasar's brilliant beam penetrated at least four separate filaments of the invisible hydrogen laced with the telltale oxygen.

Hubble's ultraviolet sensitivity and high-resolution spectroscopic capability allowed it to probe the nearby universe, where spectral features of hot gas can be seen at ultraviolet wavelengths and the problems faced by X-ray astronomers are avoided. "This result beautifully illustrates the power of spectroscopy for revealing fundamental information about the presence and nature of the gaseous matter in the universe," according to Hubble spectroscopist Blair Savage.

Still, the hot hydrogen could not be seen directly because it is fully ionized and so the hydrogen atoms are stripped of their electrons. Without electrons, no spectral features were etched into the quasar's earth-bound light. The oxygen is highly ionized too, but still retains a few electrons which absorb specific colors from the quasar's light.

NOTE TO EDITORS: A ground-based image and illustration associated with this release are available on the Internet at: http://hubble.stsci.edu/go/news


Story Source:

The above story is based on materials provided by Space Telescope Science Institute. Note: Materials may be edited for content and length.


Cite This Page:

Space Telescope Science Institute. "Lost And Found: Hubble Finds Much Of The Universe's Missing Hydrogen." ScienceDaily. ScienceDaily, 4 May 2000. <www.sciencedaily.com/releases/2000/05/000503182254.htm>.
Space Telescope Science Institute. (2000, May 4). Lost And Found: Hubble Finds Much Of The Universe's Missing Hydrogen. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2000/05/000503182254.htm
Space Telescope Science Institute. "Lost And Found: Hubble Finds Much Of The Universe's Missing Hydrogen." ScienceDaily. www.sciencedaily.com/releases/2000/05/000503182254.htm (accessed July 29, 2014).

Share This




More Space & Time News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. Video provided by Newsy
Powered by NewsLook.com
NASA EDGE: OCO-2 Launch

NASA EDGE: OCO-2 Launch

NASA (July 25, 2014) NASA EDGE webcasts live from Vandenberg AFB for the launch of the Oribiting Carbon Observatory-2 (OCO) launch. Video provided by NASA
Powered by NewsLook.com
This Week @ NASA, July 25, 2014

This Week @ NASA, July 25, 2014

NASA (July 25, 2014) Apollo 11 celebration, Next Giant Leap anticipation, ISS astronauts appear in the House and more... Video provided by NASA
Powered by NewsLook.com
Space to Ground: Coming and Going

Space to Ground: Coming and Going

NASA (July 25, 2014) One station cargo ship leaves, another arrives, aquatic research and commercial spinoffs. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins