The new findings show the outer, hotter gas halo is much larger than the previously discovered warm gas shroud. It also may help answer a long-standing cosmological mystery about baryons - particles that comprise more than 99.9 percent of the cosmos' atoms, most of which are unaccounted for.
The new research suggests the missing baryons are hiding in hot gas halos surrounding galaxies, including the Milky Way.
The research is published in the Sept. 1 issue of The Astrophysical Journal.
Image: Artist's illustration of the Milky Way surrounded by an enormous halo of hot gas (shown in blue). To the left are two small neighbor galaxies, the Small and Large Magellanic Clouds. Astronomers used NASA's Chandra, Europe's XMM-Newton, and Japan's Suzaku telescopes to get information about the halo's temperature, distance and mass. Credit: NASA/CXC/M.Weiss; NASA/CXC/Ohio State/A.Gupta et al.