Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A “Cosmic Weather Balloon” at the Centre of the Milky Way

30.09.2013
Astrophysicists determine strength of the radiation field using an intergalactic gas cloud

The radiation field at the centre of the Milky Way must be 1,000 times stronger than in the area surrounding our sun. Astrophysicists of the “Milky Way Galaxy” Collaborative Research Centre of Heidelberg University used computer simulations to reach this conclusion.

The calculations of the researchers from the Centre for Astronomy of Heidelberg University and the Max Planck Institute for Astronomy are based on the data from a type of “cosmic weather balloon” – the temperature data of an especially dense gas cloud near the centre of the Galaxy. Their research provides a new insight into the process of star formation, which is believed to take a different form at the centre of the Milky Way than it does at the Galaxy's edges.

The researchers characterise the centre of our home galaxy as an “inhospitable place”. The “weather conditions” there are reminiscent of those at stormy Cape Horn. While our more distal sun enjoys the conditions of the Galaxy's virtual Italian Riviera, a black hole and extremely hot or exploding stars create an intense “radiation wind” at the Galactic Centre. “In keeping with the metaphor, no one would ever build a ‘vacation home’ somewhere with such harsh conditions. Construction appears to be taking place nonetheless: there are gas clouds near the Galactic Centre where young stars appear to be forming,” says Dr. Paul Clark, a member of Prof. Dr. Ralf Klessen's team at the Centre for Astronomy of Heidelberg University (ZAH).

Dr. Clark and his colleagues studied an especially dense gas cloud called G0.253+0.016 more closely, and in spite of its proximity to the Galactic Centre, a large number of new stars have been observed to be forming there. Star formation is a tug of war between two forces, with gravity pulling interstellar gas inward and the internal pressure of the gas pushing outward. “Near the Galactic Centre, this gas is much hotter than at the edges of the Galaxy due to the strength of the radiation field, leading us to believe that star formation at the centre of the Milky Way differs from how we understand the process at its edges,” explains Dr. Clark.

To better understand the processes at the Galactic Centre, the “weather conditions” there – in this case the strength of the radiation field – need to be determined more precisely. So the researchers used G0.253+0.016 as a type of “cosmic weather balloon”. Astronomical observations were used to determine the temperature of the gas cloud. The data served as a basis for determining the temperature of G0.253+0.016 in relation to the radiation field. The Heidelberg astrophysicists varied the possible strength of this field until the result of the calculations matched the actual temperature measurements. The simulations took advantage of the Jülich-based “Milky Way” supercomputer that is used for projects of the Collaborative Research Centre.

The computer simulations indicated that the radiation field at the centre of the Milky Way must be 1,000 times stronger than in the area around our sun, which is located approx. 25,000 light years away at the Galaxy's edge. The Heidelberg astrophysicists believe that considerably less carbon monoxide (CO) is formed in the extreme conditions in the gas cloud. "Carbon monoxide plays a key role in most star-forming regions, as it helps to regulate the cloud temperatures. The lower CO content in the Galactic Centre clouds will have strong implications for their evolution,“ continues Dr. Clark. Further studies of the “cosmic weather balloon” should provide a complete picture of the star formation process at the centre of the Milky Way.

The results of the research were published in “The Astrophysical Journal Letters”. In addition to Dr. Clark and Prof. Klessen, the research team included Dr. Simon Glover and Dr. Rahul Shetty, as well as Dr. Sarah Ragan from the Heidelberg Max Planck Institute for Astronomy.

Internet information:
“The Milky Way System” Collaborative Research Centre:
http://www.zah.uni-heidelberg.de/de/sfb881
Original publication:
P.C. Clark, S.C.O. Glover, S.E. Ragan, R. Shetty and R.S. Klessen: On the Temperature Structure of the Galactic Center Cloud G0.253+0.016, The Astrophysical Journal Letters, Volume 768, Issue 2, article id. L34, 6 pp. (2013), doi: 10.1088/2041-8205/768/2/L34

Contact:

Dr. Paul Clark
Centre for Astronomy of Heidelberg University
Institute for Theoretical Astrophysics
Phone: +49 6221 54-8967, p.clark@uni-heidelberg.de
Dr. Guido Thimm
Centre for Astronomy of Heidelberg University
Phone: +49 6221 54-1805, thimm@ari.uni-heidelberg.de
Communications and Marketing
Press Office, phone: +49 6221 54-2311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw
Further information:
http://www.uni-heidelberg.de

More articles from Physics and Astronomy:

nachricht Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>