Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

No stars in the clouds

11.01.2006


Search for missing galaxies in high-speed galactic gas clouds ’comes up empty,’ Pitt researcher finds



A team of astronomers from the University of Pittsburgh and the Universitäts-Sternwarte München in Munich, Germany, announced today in a paper presented at the meeting of the American Astronomical Society in Washington, D.C., that their search for dwarf galaxies in fast-moving clouds of gas has yielded no results, leading them to suggest alternative avenues of research to find the supposedly "missing" galaxies.

The team, which includes Regina Schulte-Ladbeck, associate dean for undergraduate studies and professor of physics and astronomy in Pitt’s School of Arts and Sciences, and Ulrich Hopp of the Universitäts-Sternwarte München, has been searching for stars in high-velocity clouds. However, said Schulte-Ladbeck, "Our searches have come up empty."


The mathematical simulations that astronomers use to establish how galaxies were formed predict that every giant galaxy should have a few hundred "dwarf" galaxy companions. But in our own neighborhood, the Milky Way Galaxy, there are only 50 or so such dwarves.

One simple way to explain the difference would be if the missing dwarf galaxies were located in high-velocity clouds, astronomer Leo Blitz of the University of California, Berkeley, and his colleagues had suggested. Schulte-Ladbeck and Hopp hoped to measure the distances between the clouds and the Milky Way to obtain proof that the clouds indeed held additional satellite galaxies of our Milky Way.

To search for stars in the clouds, the researchers took a two-pronged approach. First, they used the Two Micron All Sky Survey, a survey conducted by the University of Massachusetts and funded primarily by NASA and the National Science Foundation, to look for bright stars in circular patches of sky two degrees across, the area typically covered by the gas clouds that make the most promising dwarf galaxy candidates.

Second, using accurate positions of where most of the hydrogen gas in several clouds is located--supplied to them by radio astronomer Jürgen Kerp of the University of Bonn--the researchers also trained one of the 8-meter (315-inch) telescopes of the European Southern Observatory’s Very Large Telescope, located in northern Chile’s Atacama Desert, on small regions within the clouds to search if any faint stars had formed there. However, neither of these methods turned up any stars.

In their paper, Schulte-Ladbeck and Hopp conclude that it is unlikely that hundreds of additional dwarf satellites of the Milky Way have been somehow "hiding" from observers, and they encourage astronomers to pursue other solutions to the discrepancy.

Karen Hoffmann | EurekAlert!
Further information:
http://www.pitt.edu

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>