Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hubble Astronomers Uncover an Overheated Early Universe

08.10.2010
If you think global warming is bad, 11 billion years ago the entire universe underwent, well, universal warming.

The consequence was that fierce blasts of radiation from voracious black holes stunted the growth of some small galaxies for a stretch of 500 million years.

This is the conclusion of a team of astronomers who used the new capabilities of NASA's Hubble Space Telescope to probe the invisible, remote universe.

Using the newly installed Cosmic Origins Spectrograph (COS) they have identified an era, from 11.7 to 11.3 billion years ago, when the universe stripped electrons off from primeval helium atoms - a process called ionization. This process heated intergalactic gas and inhibited it from gravitationally collapsing to form new generations of stars in some small galaxies. The lowest-mass galaxies were not even able to hold onto their gas, and it escaped back into intergalactic space.

Michael Shull of the University of Colorado and his team were able to find the telltale helium spectral absorption lines in the ultraviolet light from a quasar - the brilliant core of an active galaxy. The quasar beacon shines light through intervening clouds of otherwise invisible gas, like a headlight shining through a fog. The beam allows for a core-sample probe of the clouds of gas interspersed between galaxies in the early universe.

The universe went though an initial heat wave over 13 billion years ago when energy from early massive stars ionized cold interstellar hydrogen from the big bang. This epoch is actually called reionization because the hydrogen nuclei were originally in an ionized state shortly after the big bang.

But Hubble found that it would take another 2 billion years
before the universe produced sources of ultraviolet radiation with enough energy to do the heavy lifting and reionize the primordial helium that was also cooked up in the big bang.

This radiation didn't come from stars, but rather from quasars. In fact the epoch when the helium was being reionized corresponds to a transitory time in the universe's history when quasars were most abundant.

The universe was a rambunctious place back then. Galaxies frequently collided, and this engorged supermassive black holes in the cores of galaxies with infalling gas. The black holes furiously converted some of the gravitational energy of this mass to powerful far-ultraviolet radiation that would blaze out of galaxies. This heated the intergalactic helium from 18,000 degrees Fahrenheit to nearly 40,000 degrees. After the helium was reionized in the universe, intergalactic gas again cooled down and dwarf galaxies could resume normal assembly. "I imagine quite a few more dwarf galaxies may have formed if helium reionization had not taken place," said Shull.

So far Shull and his team only have one sightline to measure the helium transition, but the COS science team plans to use Hubble to look in other directions to see if the helium reionization uniformly took place across the universe.

The science team's results will be published in the October 20 issue of The Astrophysical Journal.

For illustrations and more information about these results, visit:

http://hubblesite.org/news/2010/31
http://www.nasa.gov/hubble
The Hubble Space Telescope is a project of international
cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages tthe telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

Ray Villard | Newswise Science News
Further information:
http://www.stsci.edu
http://www.nasa.gov/hubble
http://hubblesite.org/news/2010/31

More articles from Physics and Astronomy:

nachricht New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center

nachricht Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>