The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a decade, the Hubble telescope has been allowing astronomers to observe solar systems that are six or seven billion light years away.
The cosmic snake as observed by the Astronomic Institute of the University of Geneva.
(Image: Université de Genève)
Hubble suggests that there are existing galaxies of nebulae and star clusters with a diameter of over 3000 light-years. These huge accumulations (“clumps”) of stars and gas – around a thousand times larger than the Milky Way, which is relatively new in the terms of the history of the universe – seem to be the norm for older galaxies.
A gravitational lens that detects details of distant galaxies
It is very difficult to investigate these phenomena in detail over such long distances. A team from the Observatory at the University of Geneva and the Center for Theoretical Astrophysics and Cosmology at the University of Zurich are now making use of one special effect of the universe that follows its own laws:
The telescope is directed at a very massive object whose gravitational field influences the light of a faraway galaxy lying behind it. When viewed through this ‘gravitational lens’, the propagation direction of the light of the object behind it is altered. This enlarges the image and multiplies it several times.
By these means, the researchers were able to perceive distorted, elongated images that almost touched and that looked like a ‘cosmic snake’. “The image enlarged by the lens is much more accurate and brighter. We can detect galactic details that are a hundred times smaller and compare five different resolutions to determine the structure and size of these gigantic clusters”, says Daniel Schaerer, professor at the Observatory of the University of Geneva.
Observations confirm the University of Zurich’s simulations
The international research group discovered that the clumps of stars were not quite as large and massive as the first Hubble images had suggested. With this, they corroborated Valentina Tambu-rello’s earlier simulations made on a supercomputer at the University of Zurich’s Institute of Computa-tional Science. “Thanks to the incredibly high resolution of the cosmic snake, we were able to com-pare our calculations with the observations that had already been made. This was a huge stroke of luck for us”, explains the last author of the study.
The conclusion: Contrary to what had previously been assumed, the galaxy studied is not composed of one large clump of stars, but of a number of smaller ones. “Obviously, gigantic clumps in such dis-tant galaxies can only develop under very special conditions, for instance through smaller fusions or under the influence of cold gas,” Ms. Tamburello says. The fact that this was not the case had previously been impossible to detect due to the great distance involved. In her doctoral thesis, Ms. Tambu-rello had already concluded at the end of 2016 that the actual mass and size of the clumps could only be detected at a higher resolution.
Lucio Mayer, professor at the Institute of Computational Science, emphasizes: “The observations made by the University of Geneva therefore substantiate the new results from the simulations. This shows that numerical simulations can predict and anticipate astronomical observations.”
Antonio Cava, Daniel Schaerer; Johan Richard, Pablo G. Perez-Gonzalez, Miroslava Dessauges-Zavadsky, Lucio Mayer and Valentina Tamburello. The nature of giant clumps in distant galaxies pro-bed by anatomy of the Cosmic Snake. November 13, 2017, Nature Astronomy, DOI: 10.1038/s41550-017-0295-x
Prof. Lucio Mayer
Institute for Computational Science
University of Zurich
Phone +41 44 635 61 98
Department of Astronomy
Phone +41 22 379 24 02
Beat Müller | Universität Zürich
UNH scientists help provide first-ever views of elusive energy explosion
16.11.2018 | University of New Hampshire
NASA keeps watch over space explosions
16.11.2018 | NASA/Goddard Space Flight Center
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Physics and Astronomy
16.11.2018 | Physics and Astronomy
16.11.2018 | Life Sciences