Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astronomers find that galaxies are the ultimate recyclers

22.11.2011
A team of researchers from several universities and institutions, including University of Notre Dame physics faculty Chris Howk and Nicolas Lehner, has demonstrated how galaxies continue to form stars by recycling vast amounts of hydrogen gas and heavy elements across billions of years.

The researchers also identified large masses of previously undetected material surrounding galaxies, and described the large-scale flows of this gas. The results were published in three papers in the Nov. 18 edition of the journal Science.

The leaders of the three studies are Lehner of Notre Dame, Todd Tripp of the University of Massachusetts at Amherst, and Jason Tumlinson of the Space Telescope Science Institute in Baltimore. The researchers used the Cosmic Origins Spectrograph on the Hubble Space Telescope to detect the mass in the halos of the Milky Way and more than 40 other galaxies. The process uses absorption lines in the high-resolution spectra of background quasars or stars to detect the gases in the clouds, which are invisible to other kinds of imaging. Data from the Large Binocular Telescope in Arizona, Keck in Hawaii and the Magellan Telescope in Chile were also key to the studies by measuring the properties of the galaxies.

"We show that not only there is enough mass in the gas flows in halos of galaxies to sustain star formation over billions of years, but also the mass in the hot halos of star-forming galaxies is phenomenal–as large as the mass of gas in the disk of a galaxy," says Lehner.Clouds of ionized hydrogen within 20,000 light years of the Milky Way disk contain enough material to make 100 million suns. About one solar mass of that gas falls into the Milky Way every year, comparable to the rate at which our galaxy makes stars. The cycle could continue for several billion years.

In more distant galaxies, the team found element-rich halos around star-forming galaxies, including surprising levels of heavy elements up to 450,000 light years beyond the visible portion of the galactic disks. The Cosmic Origins Spectrograph measured 10 million solar masses of oxygen in a galaxy's halo, which corresponds to about 1 billion solar masses of gas.

The light of a distant quasar shines through the invisible gaseous halo of a foreground galaxy. Elements in the halo absorb certain frequencies of light. They become detectable, and can be used to measure the halo's mass.

Some of the galaxies that form stars at a very rapid rate, perhaps a hundred solar masses per year, can drive million-degree Fahrenheit gas very far out into intergalactic space at speeds of up to 2 million miles per hour. This is fast enough for the gas to escape forever and never refuel the parent galaxy. "We have observed hot gas in the process of moving out of a galaxy and into intergalactic space," Tripp says.

"Our results confirm a theoretical suspicion that galaxies expel and can recycle their gas, but they also present a fresh challenge to theoretical models to understand these gas flows and integrate them with the overall picture of galaxy formation," Tumlinson says.

Nicolas Lehner | EurekAlert!
Further information:
http://www.nd.edu

More articles from Physics and Astronomy:

nachricht Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory

nachricht SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>