Tidal disruption event AT2020opy investigated with radio telescopes

Tomasz Nowakowski is a member of the physics.org community.

The AT2020opy is a tidal disruption event that has been inspected by an international team of astronomy. The results of the study were published on the arXiv pre-print server.

The process of disruption is caused when a star passes close to a black hole and is pulled apart by the black hole's tidal force. When stellar debris starts raining down on the black hole, it's an indicator of the presence of a TDE.

TDEs are important probes of strong gravity and accretion physics for astronomy and astrophysicists.

A group of astronomer led by Adelle J. Goodwin of Curtin University in Perth, Australia, have performed radio observations of AT2020opy. The scientists looked at the radio evolution of the TDE with various telescopes.

The researchers wrote in the paper that they presented the radio detection of AT 2020opy, including three epochs of radio spectrum observations over eight months.

Radio properties of AT2020opy show that a non-relativistic outflow was launched at the time of or just after the initial optical flare. The outflow has an energy of one quindecillion erg and a constant speed of 30,000 km/s, which is roughly the same as a light year.

The radio emission from AT2020opy is most likely due to a spherical wind, collision inducing outflow or a mildly collimated jet, according to the astronomer. The circumnuclear medium of the host galaxy of AT2020opy is denser than was thought. Radio emission from the outflow increases rapidly.

Depending on the energy available in the outflow and the density of the circumnuclear medium, radio emission can continue to increase for up to years after the initial event.

The researchers found that AT2020opy is the most distant thermal TDE with radio emission reported to date. They want to continue observing the long-term decay of the radio emission.

More information: Adelle J. Goodwin et al, Radio observations of the tidal disruption event AT2020opy: a luminous non-relativistic outflow encountering a dense circumnuclear medium. arXiv:2208.13967v1 [astro-ph.HE], arxiv.org/abs/2208.13967

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