The creation of the most detailed panoramic image of the Andromeda Galaxy has been completed, which took ten years of observations from two program surveys. The 2.5-billion-pixel composite image is an inside look at our Milky Way galaxy. It is impossible for us from the inside to appreciate all the galactic features of our stellar home, and Andromeda provides clues for discovering many of them.
Image source: NASA/ESA
To take this image of Andromeda, Hubble orbited the Earth 1,000 times. 600 individual images of this galaxy were taken in the Hubble Andromeda Southern Treasury (PHAST) and Hubble Andromeda Treasury (PHAT) surveys. The galaxy seems to lie in the palm of your hand, conveniently deployed for observations from Earth at an angle of 77°. This is the closest barred spiral galaxy to us. It is 2.5 million light years away.
About 200 million stars can be found in Hubble images. This is only a small part of Andromeda’s stars and all of them are much brighter than our Sun. The latest survey to complete the panoramic image of Andromeda added information about the southern edge of Andromeda’s galactic disk. The northern region has been studied very well, which cannot be said about the south. Meanwhile, in the southern part of Andromeda, the dwarf galaxy M32 is observed and signs of external influence.
This object is also associated with a massive flow of dust, gas and individual stars, which seem to flow into the galaxy from the outside – from its halo. All together hints that these are traces of a past collision of galaxies – Andromeda and a smaller one, although this issue has yet to be studied in detail. But scientists now believe that M32 is the core left over from another galaxy absorbed by Andromeda billions of years ago.
The image of Andromeda obtained in two reviews will provide scientists with rich food for new works and discoveries. The images are available for free download at this link.