New Delhi: The Hubble Space Telescope has observed a galaxy designated as NGC 1266 at a distance of 100 million lightyears away in the constellation of Eridanus
or the Celestial River. The face-on galaxy has hints of a spiral structure, but lacks discernible spiral arms. NGC 1266 is classified as a lenticular galaxy, that represents a transitional phase between spiral galaxies and elliptical galaxies that have a smooth, lens-shaped appearance. These lenticular galaxies are named because they are shaped like lenses, with a bright central bulge, and a flattened disk, without any spiral arms. There is little to no star formation in lenticular galaxies.
What is particularly interesting about NGC 1266 is that it is a rare post-starburst galaxy, that has experienced a major burst of star formation, that has now subsided. The galaxy is evolving into a quieter elliptical galaxy. Post-starburst galaxies have a young population of stars, but no star-forming regions. About one per cent of the nearby galaxies are a post-starburst galaxy. Astronomers believe that NGC 1266 has experienced a minor merger with another galaxy about 500 million years ago. The gravitational interactions resulted in a burst of star formation, that increased the mass of the central bulge, and funnelled gas and dust towards the supermassive black hole that lurks at the galaxy core.
How black holes quench stellar nurseries
The black hole became active, voraciously feeding on the fresh supply of gas and dust, generating strong winds and jets of gas along the axis of rotation. Over time, the burst of new stars and the powerful jets from the black hole depleted the reservoir of gas and dust in the galaxy, the raw material from which stars are formed. The turbulence generated suppressed the formation of new stars. The remaining stellar nurseries are in the core of the galaxy. Post starburst galaxies such as NGC 1266 allow astronomers to study the complex processes that quench star formation.
