A team of international astronomers, including researchers from the Pune-based Inter-University Centre for Astronomy and Astrophysics ( IUCAA), has recently made a significant breakthrough in understanding the dynamics between black holes and stars. Their research centers on a star designated as AT2019qiz, which is observed crashing through the debris disk of a destroyed star approximately every 48 hours as it orbits a massive black hole. This collision leads to the release of quasi-periodic bursts of X-rays.
Discovery of Tidal Disruption Events
In 2019, astronomers first detected the signal of a star that ventured too close to a black hole, resulting in its destruction by gravitational forces. The remnants of this star formed a disk around the black hole, akin to a stellar graveyard. Over the years, this disk expanded and intersected with the orbit of another nearby star, which was initially safe from harm. As this orbiting star repeatedly crashes into the debris disk, X-ray bursts are produced, which were captured using NASA’s Chandra X-ray Observatory.
Matt Nicholl, the lead author of the study published in the current issue of Nature, illustrated the phenomenon by stating, “Imagine a diver repeatedly going into a pool and creating a splash every time s/he enters the water. The star in this comparison is like the diver and the disk is the pool, and each time the star strikes the surface, it creates a huge ‘splash’ of gas and X-rays.”
Connecting Two Cosmic Phenomena
This groundbreaking discovery offers crucial insights into two previously disconnected cosmic events. Scientists have documented various instances where objects approach black holes and are torn apart in a single burst of light, known as tidal disruption events (TDEs).
Recently, astronomers also identified a new class of bright flashes from galaxy centers, termed quasi-periodic eruptions (QPEs), which are detected solely in X-rays. Despite the connection to supermassive black holes, the cause of these repeating X-ray bursts remained unexplained until now.
Dheeraj Pasham, co-author of the study from the Massachusetts Institute of Technology, noted, “There had been feverish speculation that these phenomena are connected, and now we have discovered proof that they are. It’s like getting a cosmic two-for-one in terms of solving mysteries.”
Astro Sat's Role in Confirming Findings
The research involved a collaborative effort utilizing several space observatories, including NASA’s Chandra, Hubble Space Telescope, NICER, and Swift, alongside ISRO’s Astro Sat. The unique capabilities of Astro Sat were crucial in confirming the findings related to the star AT2019qiz.
Co-author Gulab Dewangan from IUCAA explained, “India’s Astro Sat mission provides unique UV/X-ray capability for studying such events.Astro Sat’s Soft X-ray Telescope and Ultra-Violet Imaging Telescope (UVIT) both detected the source AT2019qiz, but the eruptions were only seen in X-rays. Future sensitive simultaneous X-ray and UV observations of similar eruptions will enable a deeper investigation into their nature.”
This research not only provides valuable insights into the interactions between stars and black holes but also deepens our understanding of the underlying mechanisms of cosmic events. The collaboration between international astronomers and the involvement of Indian research institutions underscore the global effort to unravel the mysteries of the universe.
Discovery of Tidal Disruption Events
In 2019, astronomers first detected the signal of a star that ventured too close to a black hole, resulting in its destruction by gravitational forces. The remnants of this star formed a disk around the black hole, akin to a stellar graveyard. Over the years, this disk expanded and intersected with the orbit of another nearby star, which was initially safe from harm. As this orbiting star repeatedly crashes into the debris disk, X-ray bursts are produced, which were captured using NASA’s Chandra X-ray Observatory.
Matt Nicholl, the lead author of the study published in the current issue of Nature, illustrated the phenomenon by stating, “Imagine a diver repeatedly going into a pool and creating a splash every time s/he enters the water. The star in this comparison is like the diver and the disk is the pool, and each time the star strikes the surface, it creates a huge ‘splash’ of gas and X-rays.”
Connecting Two Cosmic Phenomena
This groundbreaking discovery offers crucial insights into two previously disconnected cosmic events. Scientists have documented various instances where objects approach black holes and are torn apart in a single burst of light, known as tidal disruption events (TDEs).
Recently, astronomers also identified a new class of bright flashes from galaxy centers, termed quasi-periodic eruptions (QPEs), which are detected solely in X-rays. Despite the connection to supermassive black holes, the cause of these repeating X-ray bursts remained unexplained until now.
Dheeraj Pasham, co-author of the study from the Massachusetts Institute of Technology, noted, “There had been feverish speculation that these phenomena are connected, and now we have discovered proof that they are. It’s like getting a cosmic two-for-one in terms of solving mysteries.”
Astro Sat's Role in Confirming Findings
The research involved a collaborative effort utilizing several space observatories, including NASA’s Chandra, Hubble Space Telescope, NICER, and Swift, alongside ISRO’s Astro Sat. The unique capabilities of Astro Sat were crucial in confirming the findings related to the star AT2019qiz.
Co-author Gulab Dewangan from IUCAA explained, “India’s Astro Sat mission provides unique UV/X-ray capability for studying such events.Astro Sat’s Soft X-ray Telescope and Ultra-Violet Imaging Telescope (UVIT) both detected the source AT2019qiz, but the eruptions were only seen in X-rays. Future sensitive simultaneous X-ray and UV observations of similar eruptions will enable a deeper investigation into their nature.”
This research not only provides valuable insights into the interactions between stars and black holes but also deepens our understanding of the underlying mechanisms of cosmic events. The collaboration between international astronomers and the involvement of Indian research institutions underscore the global effort to unravel the mysteries of the universe.
