La Palma Telescope Managed to Obtain the Deepest Image of Galaxy from Earth

A team astronomers from the Instituto de Astrofísica de Canarias (IAC) has deviced a new technique in observing distant and dim objects in the space using the largest optical-infrared telescope in the world.

The team managed to obtain an image 10 times deeper than any images obtained by other ground-based observatories.

For the study, the researchers mounted OSIRIS camera on the Gran Telescopio CANARIAS (GTC) at the Roque de los Muchachos Observatory in Garafía, (La Palma, Canary Islands). They chose to observe the galaxy UGC00180 for 8.1 hours. UGC00180 is 500 million light years away from Earth has certain similarities with our neighboring galaxy Andromeda and other galaxies to which they have reference.

Their findings, published in the Astrophysical Journal, showed a weak halo composed of four thousand million stars, about the same number as those in the Magellanic Clouds, which are satellite galaxies of the Milky Way. This supports the existence of stellar halos predicted by theoretical models.

At present, the widely accepted model for galaxy formation suggests that there are many stars in the outer zones of galaxies. These stars came from the destruction of other galaxies and form a stellar halo. However, stellar halos have not been fully confirmed in the past due their extremely low surface brightness, making it more difficult to prove or study.

The recent study proves to be a giant leap in understanding the universe not only to the same depth to which we can go using the conventional technique of star counts, but also out to distances where this cannot be achieved. The newly devised technique in improving the depth of image produced from ground-based observatories can also be used to determine if other structures in the sky may or may not contain stars.

"After showing that the technique works, the object of future research is to extend the study to other types of galaxies, to see whether this way of understanding their formation, predicted by the standard model, is correct or not" explained Ignacio Trujillo, a researcher at the IAC and the first author of the study, in a press release.