The NASA Observatory looked closely at the big sister of the Milky Way and discovered 40 double sources of X-rays - objects that are believed to be a key factor in heating interstellar gases and, therefore, a major factor in the evolution of the galaxy.
Nuclear Spectroscopic Telescope Array (NuSTAR) is a space telescope that can detect some of the most high-energy X-rays that the Universe can generate, and astronomers were not disappointed by spying on the Andromeda Galaxy (M31).
Andromeda, as the Milky Way, is a massive spiral galaxy that is 2.5 million light-years away. It may sound like a long distance, but Andromeda is our closest galactic neighbor. Its relative proximity allows us to study Andromeda in great detail, and some of the discoveries were presented on January 5 at the 227th meeting of the American Astronomical Society in Kissimmee, Florida.
“Andromeda is the only large spiral galaxy in which we can see individual sources of X-rays and study them in detail in an environment like ours,” said Daniel Wick, a scientist from NASA's Goddard Space Flight Center in Greenbelt, Maryland. "We can use this information to find out what happens in more distant galaxies that are difficult to see." X-ray binaries consist of two stellar objects - as a rule, one star and a stellar remnant of type neutron star or black hole. The plasma from the star is captured by a compact remnant and falls toward the hole or a neutron star, the gas undergoes rapid and intense heating - a process that can generate high-energy X-rays.
Now, using the observations of a nearby galaxy made by NuStar, astronomers can gain a deeper understanding of how X-ray binary radiation affects the galaxy and compare them with emissions from more distant galaxies.
"We conclude that black holes and neutron stars can play a decisive role in heating intergalactic gas in the early stages of galaxy evolution," said Anne Hornshemir, also from NASA Goddard Space Flight Center. "Observations of local populations of stellar objects, such as black holes and neutron stars, will help determine how much they affect the system."