Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Milky Way Maps Help Solve Stubborn Interstellar Material Mystery

18.08.2014

An international team of sky scholars, including a key researcher from Johns Hopkins, has produced new maps of the material located between the stars in the Milky Way. The results should move astronomers closer to cracking a stardust puzzle that has vexed them for nearly a century.

The maps [see video here] and an accompanying journal article appear in the Aug. 15 issue of the journal Science. The researchers say their work demonstrates a new way of uncovering the location and eventually the composition of the interstellar medium—the material found in the vast expanse between star systems within a galaxy.

This material includes dust and gas composed of atoms and molecules that are left behind when a star dies. The material also supplies the building blocks for new stars and planets.

“There’s an old saying that ‘We are all stardust,’ since all chemical elements heavier than helium are produced in stars,” said Rosemary Wyse, a Johns Hopkins professor of physics and astronomy who played a prominent role in the research and helped shape the Science paper. “But we still don’t know why stars form where they do. This study is giving us new clues about the interstellar medium out of which the stars form.”

... more about:
»Galaxy »Maps »RAVE »astronomy »dark »interstellar »materials »starlight

In particular, the researchers focused on a mysterious feature in the light from stars, a peculiarity called diffuse interstellar bands, or “DIBS.” A graduate student who photographed the light from distant stars discovered these dark bands in 1922.

Analyzing rainbow-colored bands of starlight that have passed through space gives astronomers important information about the makeup of the space materials that the light has encountered. But in 1922, the grad student’s photographs yielded some dark lines indicating that some starlight was “missing’’ and that something in the interstellar medium between Earth and the star was absorbing the light.

Since then, scientists have identified more than 400 of these diffuse interstellar bands, but the materials that cause the bands to appear and their precise location have remained a mystery.

Researchers have speculated that the absorption of starlight that creates these dark bands points to the presence of unusually large complex molecules, but proof of this has remained elusive. The nature of this puzzling material is important to astronomers because it could provide clues about the physical conditions and chemistry of these regions between stars. Such details serve as critical components in theories as to how stars and galaxies are formed.

Wyse said more concrete clues should emerge from the new pseudo-3D maps of the DIB-material within our Milky Way Galaxy, maps that were produced by the 23 scientists who contributed to the Science article.

The maps were assembled from data collected over a 10-year period by the Radial Velocity Experiment, also known as RAVE. This project used the UK Schmidt Telescope in Australia to collect spectroscopic information from the light of as many as 150 stars at once. The maps are described as “pseudo-3D” because a specific mathematical form was assumed for the distribution in the vertical dimension that provides the distances from the plane of the Milky Way, with the maps presented in the remaining two dimensions.

Wyse, who is on the executive board of the RAVE project, said the survey supplied the mapmakers with data related to 500,000 stars. The vast size of the sample enabled the mapmakers to determine the distances of the material that causes the DIBs and thus how the material is distributed throughout the Milky Way Galaxy.

The resulting maps showed the intriguing result that the complex molecules thought to be responsible for the DIBs are distributed differently than another known component of the interstellar medium – the solid particles known as dust – also traced by the RAVE survey.

Future studies can use the techniques outlined in the new paper to assemble other maps that should further solve the mysteries surrounding where DIBS are located and what materials cause them. “To figure out what something is, you first have to figure out where it is,” Wyse said, “and that’s what this paper does. Larger surveys will provide more details in the future. This paper has demonstrated how to do that.”

Janez Kos and Tomaz Zwitter of the University of Ljubljana in Slovenia led the astronomy team that produced this paper. Wyse was the third author listed on the paper.

A portion of the funds for this project came from U.S. National Science Foundation grant AST-0908326.

RAVE is a multinational project with participation of scientists from Australia, Germany, France, UK, Italy, Canada, the Netherlands, Slovenia and the USA, coordinated by the Leibniz Institute for Astrophysics Potsdam (AIP), Germany. Funding of RAVE, which guarantees extensive data, telescope and instrument access is provided by the participating institutions and the national research foundations.

Photo of Professor Wyse available; contact Phil Sneiderman.

Related links:

RAVE Survey Website:
http://www.rave-survey.org

Online video of stars observed by RAVE:
http://www.rave-survey.aip.de/rave/movies/ravedr4_anim.mp4

Rosemary Wyse’s Website:
http://physics-astronomy.jhu.edu/directory/rosemary-f-g-wyse/

Henry A. Rowland Dept. of Physics and Astronomy at Johns Hopkins:
http://physics-astronomy.jhu.edu/

Zanvyl Krieger School of Arts & Sciences at Johns Hopkins: http://krieger.jhu.edu/

Johns Hopkins University news releases are available online, as is information for reporters. Find more Johns Hopkins stories on the Hub.

Phil Sneiderman | newswise

Further reports about: Galaxy Maps RAVE astronomy dark interstellar materials starlight

More articles from Physics and Astronomy:

nachricht A New Litmus Test for Chaos?
29.07.2015 | American Institute of Physics (AIP)

nachricht First detection of lithium from an exploding star
29.07.2015 | ESO

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: On the crest of the wave: Electronics on a time scale shorter than a cycle of light

Physicists from Regensburg and Marburg, Germany have succeeded in taking a slow-motion movie of speeding electrons in a solid driven by a strong light wave. In the process, they have unraveled a novel quantum phenomenon, which will be reported in the forthcoming edition of Nature.

The advent of ever faster electronics featuring clock rates up to the multiple-gigahertz range has revolutionized our day-to-day life. Researchers and...

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

Im Focus: Unlocking the rice immune system

Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...

Im Focus: Smarter window materials can control light and energy

Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.

By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...

Im Focus: Simulations lead to design of near-frictionless material

Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. Argonne Leadership Computing Facility (ALCF) researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team's code.

While reviewing the simulation results of a promising new lubricant material, Argonne researcher Sanket Deshmukh stumbled upon a phenomenon that had never been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

 
Latest News

Surprising similarity in fly and mouse motion vision

30.07.2015 | Life Sciences

Efficient Infrared Heat Saves Time and Energy in the Manufacture of Motor Vehicle Carpets

30.07.2015 | Trade Fair News

Roentgen prize goes to Dr Eleftherios Goulielmakis

30.07.2015 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>