India’s AstroSat Sees ‘Direct’ Formation of Dwarf Galaxy
The Earth occupies a very small part of the Milky Way, itself a very small part of the universe, and despite its expansion, the Milky Way does not undergo new star formation. However, the Milky Way is surrounded by dwarf galaxies that are full of possibilities and give birth to stars that are packing it.
AstroSat, India’s first dedicated multi-wavelength space observatory, has now seen star-forming complexes at the periphery of a dwarf galaxy move towards the center and contribute to the growth of a dwarf galaxy. grow in its mass and luminosity. Astronomers have long tried to answer questions like how these dwarf and giant galaxies gathered their stars and evolved into present-day galaxies, like our own.
An international team of astronomers, including from India, has detected faint emission of Far Ultraviolet (FUV) light on the outskirts of a sample of the Blue Compact Dwarf galaxy. blue (BCD) is about 1.5-3.9 billion light-years away. The resolving power of UVIT and UV deep-field imaging techniques is key to detecting these very young, large star-forming clusters.
Research has been published in the journal Nature.
Led by Anshuman Borgohain, a Ph. Students at the University of Tezpur, Assam, the team calculated the time it took for the clusters to move inside the galaxy.
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“Capturing assembly in dwarf galaxies is considered important because the diversity in their physical properties observed today challenges current theoretical models of galaxy evolution. river. AstroSat/UVIT has been a notable addition to the roster of UV observatories to date and has opened promising doors for probing an understanding of galactic assembly,” Anshuman said. in a statement issued by the Interuniversity Center for Astronomy and Astrophysics (IUCAA).
The researchers say that the observations suggest that gas accumulating in the far outer parts may be forced to move towards the center due to internal torques created by the gas and star complexes huge. This migration increases the central density over the lifetime of the galaxy.
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The researchers claim that the biggest challenge is firmly establishing the detection of faint star-forming clusters, extremely blue, very far away to be seen, and at a slightly greater distance, UVIT will not resolve these galaxies. The redshift (cosmic distance) of these 12 dwarfs is just optimal for probing these blue cluster structures in their suburbs.
“The discovery tells us how surprisingly stars can form in disks of metal-poor gas. Normally these dwarf galaxies are dominated by dark matter and the gas disk would not be destabilized. But our findings are direct evidence that there are even such gas disc fragments,” said Professor Francoise Combes of the Observatoire de Paris, France, co-author of the study.
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