Astronomers of the Universities of Tübingen and Vienna are investigating the basic principles of the formation of stars
“How do massive stars form?” is one of the fundamental questions in modern astrophysics, because these massive stars govern the energy budget of their host galaxies. Using numerical simulations, Professor Wilhelm Kley, Dr. Rolf Kuiper and Dr. Dominique Meyer from the Institute for Astronomy and Astrophysics at the University of Tübingen in a collaboration with Dr. Eduard Vorobyov from the Institute for Astrophysics at the University of Vienna revealed new components of the formation of massive stars, which were already known from the formation process of low-mass as well as primordial stars. The study has now been published in the peer-review journal Monthly Notices of the Royal Astronomical Society.
The birth of massive stars is still a mystery to us, because these stars are embedded in an extremely dense medium of gas and dust, says Rolf Kuiper, the leader of the Emmy Noether Research Group for Massive Star Formation, funded by the German Research Foundation (DFG).
“This opaque envelope makes it difficult to directly observe the birth process even with modern telescopes. In other words, we see the cradle in which these stars are born, but we can’t detect the stars themselves.” Therefore, the researchers modeled the birth process within a numerical simulation. For this ambitious, computationally expensive study they made use of high-performance computers within the bwHPC initiative of the state of Baden-Württemberg.
The simulation starts with a cloud of gas and dust, which collapses under its own gravity and eventually forms a so-called accretion disk around the hot young star. The material in such a disk rotates around the central star and slowly transports gas and dust towards it. For the first time, the resolution of these simulations was sufficient to infer the formation of high-density clumps within the gravitationally unstable disk. Once formed, these clumps start to migrate through the disk and finally sink into the central star. “Like throwing logs into a fireplace, these episodes of clump consumption produce violent luminosity outbursts outshining the collective effect of one hundred thousand Suns,“ says Eduard Vorobyov.
A similar process of episodical luminosity bursts was already known with respect to the formation of the first stars in the Universe and for low-mass stars like our Sun. The new investigation suggests now that the formation of stars of any kind and epoch are controlled by the same universal processes: “It is amazing to see these similarities, as if star formation on all scales and epochs is controlled by a common DNA forged in the early Universe,“ says Dominique Meyer, the first author of the study and post-doc in the Emmy Noether Group. The clumps, explains Wilhelm Kley, are also excellent candidates for the formation of Solar-type companions to massive stars: “These companions will also influence their future evolution.”
The results will help to develop new observing strategies for detecting these luminosity outbursts – and even for directly imaging the high-density clumps in accretion disks around very young massive stars. This will be a task for modern observing facilities such as the Atacama Large Millimeter Array (ALMA) of the European Southern Observatory (ESO) or the future European Extremely Large Telescope (E-ELT).
D. M.-A. Meyer, E. I. Vorobyov, R. Kuiper and W. Kley: On the existence of accretion-driven bursts in massive star formation. Monthly Notices of the Royal Astronomical Society, DOI: 10.1093/mnrasl/slw187, http://mnrasl.oxfordjournals.org/content/early/2016/09/15/mnrasl.slw187.abstract
Prof. Dr. Wilhelm Kley
University of Tübingen
Institute for Astronomy and Astrophysics
Phone +49 7071 29-74007
Dr. Rolf Kuiper
University of Tübingen
Institute for Astronomy and Astrophysics
Emmy Noether Research Group for Massive Star Formation
Phone + 49 7071 29-75490
Dr. Eduard Vorobyov
University of Vienna
Institute for Astrophysics – Star and Planet Formation
Phone + 43 1 4277 538 15
http://www.tat.physik.uni-tuebingen.de/~msf - Emmy Noether Research Group on Massive Star Formation
http://www.physik.uni-tuebingen.de/institute/astronomie-astrophysik/institut.htm... - Institute for Astronomy and Astrophysics Tübingen
http://www.univie.ac.at/stars/ - Star & Planet Formation Group of the Department of Astrophysics Vienna
http://www.bwhpc-c5.de/ - High-performance Cluster Coordination bwGrid Baden-Württemberg
Dr. Karl Guido Rijkhoek | idw - Informationsdienst Wissenschaft
Meteoritic stardust unlocks timing of supernova dust formation
19.01.2018 | Carnegie Institution for Science
Artificial agent designs quantum experiments
19.01.2018 | Universität Innsbruck
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy