An impressive new series of images has unveiled the breathtaking view of neighboring galaxies, thanks to the VLT Survey Telescope (VST) stationed at the European Southern Observatory’s Paranal facility in Chile. Among these celestial bodies is the notable Sextans A, a diminutive dwarf galaxy with a unique square shape that lies a mere 4 million light-years from Earth.
Sextans A, depicted above, measures just 5,000 light-years in diameter, making it significantly smaller than our Milky Way. Its unusual shape has been sculpted by monumental supernova explosions, which occur at the end of a star’s life cycle, scattering the galactic material and resulting in its distinctive configuration.
This galaxy, along with others like NGC 3109 shown above, is being studied to deepen our understanding of galaxy formation through a project titled The VLT Survey Telescope Survey of Mass Assembly and Structural Hierarchy (VST-SMASH). Altogether, the initiative encompasses the analysis of 27 galaxies.
“Our goal is to explore how galaxies are formed based on their mass and structure. This involves examining both the in-situ formation of stars within galaxies and the processes by which they are accrued during galactic mergers,” explained Crescenzo Tortora, the lead researcher from the Italian National Institute for Astrophysics. “To achieve this, we trace the colors of these galaxies to their outer regions, investigating faint structures and nearby galaxies. This information helps reveal remnants of past galactic interactions, thereby refining our understanding of cosmic structure formation.”
Other galaxies highlighted in this research include the spiral galaxy IC 5332, positioned 30 million light-years away, the irregular galaxy NGC 5253, which is 11 million light-years distant, and NGC 5236, also known as the Southern Pinwheel, located 15 million light-years from us. The Southern Pinwheel is particularly eye-catching as one of the closest and brightest barred spiral galaxies visible, often observable with binoculars due to its proximity.
“This is the first instance where all these galaxies have been observed with such depth and detail, alongside consistently gathered data,” Tortora remarked. “In the years to come, only the Euclid mission is expected to achieve similar depth in optical surveys, but it will lack the broad spectral range available with the VST. The Vera Rubin Observatory will observe in similar spectral ranges to ours but will take several years to reach comparable depths. Consequently, VST continues to be a vital tool, and we remain optimistic for intriguing results from our survey.”
Additional insights can be found in the latest issue of the ESO Messenger, accessible through this link: The Messenger.
