Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Where is the gas in interstellar space?

17.04.2007
A team of astronomers led by Professor Martin Barstow of the University of Leicester have searched for the hot gas thought to be present in the interstellar space around the Sun but found it just isn’t there.

Speaking at the Royal Astronomical Society National Astronomy Meeting in Preston on Tuesday 17 April, Professor Barstow will present a map of the local interstellar medium, the gas lying between the stars out to distances of about 300 light years from the Sun, made using the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite.

Professor Barstow and his team used FUSE to observe a group of white dwarf stars (compact remnants of stars like our Sun will be at the end of its life). The scientists intended to probe the structure of interstellar space in the vicinity of the Sun by searching for the imprint of oxygen in the ultraviolet light from the stars. However, all the oxygen detected was found to be in the atmospheres of the stars and no interstellar oxygen was found. This implies that, rather than being full of tenuous ionized gas, as expected, this region of interstellar space (the Local Cavity) is actually empty and was probably swept clear by an ancient supernova explosion a few million years ago.

Our present picture of the local interstellar medium is that the Sun and Solar system are embedded in and near the edge of a wispy diffuse cloud, known as the Local Cloud (or Local Fluff). This cloud, which is only 20-30 light years across, is itself in a larger much less dense region called the Local Bubble or Local Cavity.

The gas in the Local Cavity was expected to bear the scars of recent nearby events, such as supernova explosions, and radiation from hot young stars. These would make the cavity gas hot and ionized, with the electrons stripped from the constituent atoms, and should be detected by FUSE. The hot gas should emit also X-rays that are detected as a diffuse background in X-ray telescopes. However, if there is no hot gas present, then we need to find another explanation for this X-ray background. One novel suggestion is that it arises from the exchange of charged particles at the boundary between the Sun’s magnetic field and interstellar space.

Robert Massey | alfa
Further information:
http://www.ras.org.uk
http://www.nam2007.uclan.ac.uk/press.php

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

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

NSF-supported researchers to present new results on hurricanes and other extreme events

19.07.2018 | Earth Sciences

Scientists uncover the role of a protein in production & survival of myelin-forming cells

19.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>