Galaxies are divided into sphere-like and thin disk (like our own Milky Way). New observations made with the Space Telescope, "Spitzer" have revealed the Sombrero galaxy, which has characteristics of both a sphere-like and disk of the galaxy. It is a round elliptical galaxy with a thin disk inside. This discovery will allow a better understanding of the area in which there are still many dark spots - the evolution of galaxies.
"Sombrero is not as simple as previously thought," - said Dimitri Gadotti of the European Southern Observatory in Chile, the lead author of a new paper in the journal Monthly Notices of the Royal Astronomical Society. "The only way to understand what this galaxy, this think of it as two galaxies, one inside the other."
Sombrero Galaxy, also known as NGC 4594, is located at a distance of 28 million light-years away in the constellation Virgo. When viewed from Earth, you can see the thin edge of a flat disk and a central bulge (spherical projection), which in appearance resemble a wide-brimmed hat. The angle at which the disk is not to determine from Earth, what is the shape of a disk: spiral or ring.
"It presents us with new issues," - said Ruben Sanchez-Janssen from the European Southern Observatory, co-author of the study. "How did such a large disk formed and survived in such a massive elliptical? How common is this type of galaxy?".
The researchers reported that the answers to these questions will allow them to better understand the process of the evolution of other galaxies. Another galaxy called Centaurus A, also looks like an ellipse with a disc inside. But this disc does not contain so many stars. According to astronomers, the Centaurus A may be located at an earlier stage of evolution than the Sombrero and might one day take the identical form.
This discovery will shed light on the mystery associated with the number of globular clusters in the Sombrero galaxy. Globular clusters - globular clusters is composed of old stars. Elliptical galaxies usually contain several thousand, and the spiral - a few hundred. Sombrero has almost 2,000, putting scientists into a dead end when they thought it was only the disc galaxy.