Most of the stars in our universe die of natural causes : exploding their outer layers, by means of an explosion that ends in the form of a supernova or simply cooling due to lack of fuel .
However, stars that live in the inner zone of your galaxy may not be so lucky. The supermassive black hole that lives at the heart of most galaxies could pull on them so much that it ends up tearing them apart. Astronomers call this process “spaghetti” (although its proper name is a tidal disruption event). However, despite knowing about its existence, this is the first time we have been able to observe this event.
A team of astronomers, including lead researcher Giacomo Cannizzaro and Peter Jonker from the SRON Space Research Institute of the Netherlands / Radboud University, have observed spectral absorption lines caused by strands of a spaghetti star.
And we had never seen the actual material ligaments, as in a physical object that not only emits light but also blocks. These spectral absorption lines have been contemplated while observing one of the poles of a black hole; specifically AT 2019dsg
It was already evident that black holes may have a disk of accretion material around their equator, but absorption lines on the pole of a black hole suggest that there is a long strand wrapped many times around the black hole, like a ball of thread: the actual material of a freshly torn star.
The accretion disk is the only part of a black hole system that emits X-ray radiation that astronomers can measure. If you looked straight ahead, you wouldn’t see the X-rays of the accretion disk.
“In addition, the absorption lines are narrow,” says Giacomo Cannizzaro (SRON / Radboud University), leader of the work that publishes the Monthly Notices of the Royal Astronomical Society . “They do not magnify with the Doppler effect, as you would expect when looking at a spinning disk.”
What exactly is a tidal disruption event?
Stars in the vicinity of supermassive black holes (SMBH) can be ripped apart by the tidal forces of the black hole . The subsequent accumulation of stellar material causes a spectacular flash of electromagnetic radiation. The TDE ( Tidal Disruption Event ) represent a new probe of matter subjected to strong gravity and opened a new window to study the physics of accretion under extreme conditions.
The mass of a black hole also determines its “tidal disruption radius,” or the radius at which the black hole is likely to break a star. The tidal disruption radius is scaled to 1/3 power with the mass of the black hole, which means that a black hole that is 8 times more massive will have a tidal disruption radius that is only 2 times as massive. .
Referencia: G Cannizzaro , T Wevers, P G Jonker, M A Pérez-Torres, J Moldon, D Mata-Sánchez, G Leloudas, D R Pasham, S Mattila, I Arcavi et al. Accretion disc cooling and narrow absorption lines in the tidal disruption event AT 2019dsg, Monthly Notices of the Royal Astronomical Society (2021). Published: 24 March 2021 DOI: 10.1093/mnras/stab851
