Hubble Spots Giant Gas Halo Around Andromeda Galaxy

NASA's Hubble Space Telescope has spotted a giant gas halo around the Andromeda Galaxy, something that is said to be so large it stretched approximately a million lightyears from the Andromeda Galaxy and halfway to the Milky Way. The discovery was made by a team of researchers being led by Notre Dame's Nicolas Lehner, an astrophysicist. With this discovery, researchers will be able to discern more about these massive spiral galaxies, including both the Andromeda Galaxy and the Milky Way.

The gas halo is said to be invisible, requiring the researchers to locate bright objects in the background and note the gas's effect on their light. Quasars are cited as one excellent object for this taste, with their brightness dimming ever so slightly as the light passes through the gas toward the telescope.

According to Notre Dame, this is the first giant halo around a galaxy that has been spotted this close to Earth but beyond the Milky Way. A total of 18 quasars were used to ascertain the halo's size, which is said to be approximately 100 times the moon's diameter. The Andromeda Galaxy itself is located about 2.5 million lightyears away.

The researchers are said to have used five years of Hubble data as part of their researcher, and they looked at the ultraviolet light to get details on the extent and nature of galaxy gas halos. If, says the researchers, the Milky Way has a similar halo, the two halos could one day merge before the galaxies collide, making a giant elliptical galaxy...in about another 4 billion years.

SOURCE: Notre Dame News