Herschel Captures Andromeda Galaxy's Stars in High-Resolution Infrared Wavelengths

The Herschel Space Observatory has taken a series of stunning images of the galaxy, Andromeda. The new images are the first time that astronomers have seen Andromeda in high-resolution infrared wavelengths. The new images will allow scientists to study individual regions of the galaxy as small as about 400 light-years.

The Andromeda galaxy is also known as M31. It's our largest neighbor and in astronomical terms, it's relatively close to us-only 2.2 million light-years away. This gives astronomers the opportunity to better study the galaxy in great detail, including with the new images.

"It is the first time that we can see M31 at these wavelengths at such a high resolution," said Jacopo Fritz, one of the researchers in a news release.

These images taken at different wavelengths, including ultraviolet, visible and near infrared, allowed scientists to build a complete picture of the components that constitute a galaxy, including stars, gas and dust. This collection of data gave astronomers the opportunity to study where these different components were located and how they interact with one another.

"By studying the light emitted from these regions at many wavelengths, we found something completely counter-intuitive, which we did not expect," said Sebastien Viaene, one of the researchers. "Astronomers believe that the dust that permeates the space between the stars in galaxies is predominantly heated by recently born, massive stars. These are very luminous and emit lots of ultraviolet radiation, which is very efficient in heating the dust. Hence, dust emission is very often used to calculate the amount of new stars a galaxy is producing. Instead, in the bulge of M31, where the dust temperature reaches its maximum, we see that the dust is predominantly heated by the older stars."

The findings reveal a bit more about the Andromeda galaxy and show astronomers a bit more about the role of older stars.

The findings are published in the journal Astronomy & Astrophysics.