3D Maps of Milky Way Offer New Insights Into Stardust
Days after researchers announced capturing the first known particles of stardust from outside our solar system, new maps of the Milky Way galaxy are providing more insight about the nature of matter between stars.
Explained in a paper published in the Aug. 15 issue of the journal Science, an international team of astronomical scholars has produced new 3D maps of the material located between star systems in the Milky Way, otherwise known as stardust, the stuff from which all things originated, scientists believe.
That material includes dust and gas composed of atoms and molecules -- which are from the deaths of stars and then provide the fundamental 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," research leader Rosemary Wyse, a Johns Hopkins University professor of physics and astronomy who contributed to the journal article, said in a school news release. "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."
The research team focused-in on a peculiar phenomenon detected in starlight called diffuse interstellar bands ("DIBs") which were first discovered back in 1922 when a graduate student photographed the light from distant stars that apparently included dark bands.
Analyzing rainbow-colored bands of starlight passed through space today provides astronomers vital data about the composition of space materials the light has encountered on its long trip to Earth.
At the turn of the last century, the grad student's images of the mysterious dark lines indicated that some of the starlight was absorbed by some kind of interstellar materials between Earth and the star or stars emitting the light.
Since then, more than 400 of such DIBs have been documented, although the identity and location of the materials in question have continued a mystery.
Researchers have speculated that the presence of the dark bands reveals the absorption of light by unusually large and complex molecules, although such theories have yet to be proven.
Wyse said better evidence should be provided by the new 3D maps of the DIB-material in the Milky Way, 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, which employs the U.K. Schmidt Telescope in Australia to collect spectroscopic information from the light of as many as 150 stars at once.
Wyse said the survey supplied the mapmakers with data related to 500,000 stars -- a sample size that enabled 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 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.
"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."
Subscribe to Latin Post!
Sign up for our free newsletter for the Latest coverage!