New Recipe for Dwarf Galaxies: Start with Leftover Gas
Office of News and Information - Johns Hopkins University - 901 South Bond Street - Suite 540 - Baltimore, Maryland 21231 - Phone: 443-287-9960 - Fax: 443-287-9920 February 18, 2009 - FOR IMMEDIATE RELEASE - Johns Hopkins Media Contact: Lisa De Nike - 443-287-9960, Lde [a] jhu (p) edu - JPL/NASA Media Contacts: Whitney Clavin and - Rhea Borja - 818-354-4673/354-0850 There is more than one way to make a dwarf galaxy, and NASA's Galaxy Evolution Explorer has found a new recipe. It has, for the first time, identified dwarf galaxies forming out of nothing more than pristine gas likely leftover from the early universe. Dwarf galaxies are relatively small collections of stars that often orbit around larger galaxies like our Milky Way. The findings surprised astronomers because most galaxies form in association with a mysterious substance called dark matter or out of gas containing metals. The infant galaxies spotted by the Galaxy Evolution Explorer are springing up out of gas that lacks both dark matter and metals. Though never seen before, this new type of dwarf galaxy may be common throughout the more distant and early universe, when pristine gas was more pervasive. Led by David Thilker of the Henry A. Rowland Department of Physics and Astronomy at The Johns Hopkins University, a team of astronomers spotted the unexpected new galaxies forming inside the Leo Ring, a huge cloud of hydrogen and helium that traces a ragged path around two massive galaxies in the constellation Leo.
