Indian researchers, in collaboration with scientists from France, have discovered a faint star-forming galaxy using the Ultraviolet Imaging Telescope (UVIT) aboard AstroSat, India’s only space observatory. The galaxy was found around 136 million light years away.
The galaxy, which has been named UVIT J2022, remained undetected as it lay in front of a much brighter galaxy, located further away. It was earlier thought that the UVIT J2022 was an interacting galaxy because of the background and foreground’s superimposition.
With optical telescopes getting more powerful, researchers can now detect more such extremely faint galaxies — ones with lower surface brightness than the sky surrounding it, The Indian Express reported. Such faint galaxies are believed to account for up to 15% of the universe’s mass, but researchers are still looking to find them.
The Indo-French team of researchers first got a hint that the UVIT J2022 might be a separate entity while studying the NGC 6902A galaxy in the background using the Dark Energy Camera Legacy Survey colour image that showed excess Far Ultraviolet.
Far Ultraviolet is normally found in the galaxy’s star-forming regions and is emitted by two types of massive and short-lived young stars. When the researchers further probed into it, they found that the star-forming region detected using FUV was 136 million light years away while the background galaxy NGC 6902A is located at a distance of 825 million light years, indicating that these were two different galaxies, The Indian Express reported.
The research was conducted by a team that included Mousumi Das, Jyoti Yadav, and Sudhanshu Barway from the Indian Institute of Astrophysics, Bangalore, in collaboration with Francoise Combes of College de France, Chaire Galaxies et Cosmologie, Paris. Other than the UVIT aboard AstroSat, the researchers also used data from the Multi-Unit Spectroscopic Explorer instrument on the Very Large Telescope in Chile, Infra-Red Survey Facility in South Africa, and Dark Energy Camera Legacy Survey.
The research was published in the Astronomy & Astrophysics journal.
