The VLT Survey Telescope at ESO’s Paranal Observatory in Chile has broken new ground in galaxy research. Impressive photographs of neighboring galaxies obtained with this instrument offer a glimpse into the mysteries of the formation of these cosmic structures.
One of the most exciting is the Sextant A galaxy, a dwarf galaxy located “only” 4 million light-years away. Its size is relatively small – only 5,000 light-years across, which is 5% of the size of our Milky Way. The uniqueness of this galaxy lies in its unusual square shape, which resulted from powerful supernova explosions. These events contributed to the redistribution of the galaxy’s material and gave it its characteristic configuration.
Sextant A, like its neighboring galaxy NGC 3109, has been the subject of a survey as part of the VST-SMASH (VLT Survey of Mass Assembly and Structural Hierarchy) project. In total, scientists have studied 27 galaxies to find out the mechanisms of their formation.
“We are trying to understand how galaxies form, as a function of their mass and morphological type. This means asking how stars form in situ, inside galaxies, but also how they are accumulated (ex situ) through merging processes, that is, fusion, with other galaxies” explained Crescenzo Tortora from the Italian National Institute of Astrophysics. According to the scientist, studying the colors of galaxies and the weak structures that surround them can reveal the remnants of past galactic interactions that form the cosmic hierarchy.
Other interesting galaxies were also included in the study:
- IC 5332 a spiral galaxy located 30 million light-years away.
- NGC 5253 – an irregular galaxy located 11 million light-years away.
- NGC 5236, known as the Southern Pinwheel, is a spiral galaxy that is one of the closest and brightest in the sky – it is located 15 million light-years away and is visible even through binoculars.
“This is the first time that all these galaxies have been observed in such a deep and detailed way, and with homogeneous data,” Tortora noted.
Although new telescopes such as Euclid or the Vera Rubin Observatory will be able to achieve similar observing depths, VST remains a unique instrument. Its ability to study galaxies in great detail continues to bring important scientific results.
These discoveries bring us closer to understanding the complex processes of galaxy formation and cosmic structure in general.
Provided by phys.org
