Unbelievably, we now know what makes up our galaxy.
By analyzing the light of hundreds of thousands of celestial objects, Johns Hopkins astronomers from the Sloan Digital Sky Survey (SDSS) have created a unique map of enigmatic molecules in our galaxy that are responsible for puzzling features in the light from stars.
The map, which can be viewed at http://is.gd/dibmap, was unveiled Jan. 8 at the 225th meeting of the American Astronomical Society in Seattle. “Seeing where these mysterious molecules are located is fascinating,” said Brice Ménard, a professor in the Department of Physics & Astronomy at The Johns Hopkins University..
These puzzling features in the light from stars, which astronomers call “Diffuse Interstellar Bands” (DIBs), have been a mystery ever since it was discovered by astronomer Mary Lea Heger of Lick Observatory in 1922. While analyzing the light from stars, she found unexpected lines that were created by something existing in the interstellar space between the stars and the Earth.
Further research showed that these mysterious lines were due to a variety of molecules. But exactly which of many thousands of possible molecules are responsible for these features has remained a mystery for almost a century.
This new map, reveals the location of these enigmatic molecules, was compiled from two parallel studies. Astronomers analyzed the light from more than half a million stars, galaxies, and quasars to detect the molecules’ features in the regions well above and beyond the Milky Way’s disk.
Astronomers also found the types of environments in which these molecules are more likely to be found. Some molecules like dense regions of gas and dust, and others prefer the lonelier spots far away from stars.