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 Basque researchers turn light upside down
23.02.2018 | Elhuyar Fundazioa

nachricht Attoseconds break into atomic interior
23.02.2018 | Max-Planck-Institut für Quantenoptik

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: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>