Astronomers have discovered the faintest optical event closest to the destruction of a star by a black hole.

Astronomers have discovered the faintest optical event closest to the destruction of a star by a black hole.

Astronomers have discovered the faintest optical event closest to the destruction of a star by a black hole.

Formed in spiral galaxy NGC 3799 Astronomers have discovered a tidal disturbance in a star caused by a supermassive black hole. This is the closest event to Earth in the optical wavelength range, and also the lowest in magnitude. It formed at the center of spiral galaxy NGC 3799. A preprint of this study is available at arXiv.org. The tidal destruction phenomenon occurs when a star gets close enough to a supermassive black hole that the tidal forces from it overcome the star’s gravity, causing it to be partially or completely destroyed. The result is an episode of accretion of stellar material onto the black hole, in which ground-based observers observe flashes of light in broad-spectrum waves. Such phenomena make it possible to study the activity of hitherto silent black holes, the physics of accretion, and the formation of jets and shock waves. A team of astronomers led by Willem Hoogendamm of the University of Hawaii Institute for Astronomy has reported the discovery of ASASSN-23bd, the closest tidal disruption event to Earth observed in the optical range. First discovered on February 22, 2023 by the ground-based robotic system ASAS-SN, followed by photometric and spectroscopic observations at multiple wavelengths by ground-based and space-based telescopes such as the Keck Observatory, TESS, Swift, XMM-Newton, and Hubble. was held. . The flare’s host galaxy, NGC 3799, is a barred spiral galaxy located approximately 160 million light-years from the Sun in the constellation Leo. This galaxy is a liner galaxy that interacts gravitationally with neighboring galaxy NGC 3800, activating star formation within it. Although no strong activity has been observed at the center of the supermassive black hole, the possibility of weak activity cannot be ruled out. The mass of the central supermassive black hole, estimated from the mass of the galaxy’s stars, is 1.6 million solar masses. Scientists have ruled out the theory that the burst is a Type II supernova, or a burst of activity at the galactic center. Instead, the idea of ​​tidal disturbance applies. The source began to brighten nine days before its discovery, with a maximum optical and ultraviolet luminosity of 5.4 × 1042 ergs per second, decreasing by 0.7 orders of magnitude over 40 days. The brightness of the flare at the time of registration was 16.3 mag in G band. These properties make ASASSN-23bd the optically closest tidal disruption event, changing its brightness about twice as fast as similar events, and also being the lowest in brightness. It is part of a population of LLAT-type tidal disruption events, characterized by low luminosity and rapid brightness increases.

source: https://arxiv.org/abs/2401.05490