USATODAY.com – Ongoing growth: Galaxies grab intergalactic gas
The spherical gas halo was found centered on the nucleus of NGC 5746, a spiral galaxy like our own Milky Way. The halo, not visible in optical wavelengths, has a radius of about 60,000 light-years and was detected with NASA’s Chandra X-ray Observatory.
“The halos exist, but are so faint that an extremely sensitive telescope such as Chandra is needed to detect them,” Pedersen said.
Without a hot halo of gas, scientists would expect star formation within galaxies to eventually cease.
“If halos didn’t exist, it would just be a big coincidence,” Bower said. “Why do we just happen to exist in this epoch where galaxies are on the verge of running out of gas? The existence of hot halos that are refueling the galaxy makes that much less of a paradox.”