A recent discovery has revealed a fascinating phenomenon in a distant galaxy, featuring two supermassive black holes which revolve around each other and disrupt an immense cloud of gas. This event, called At 2021hdrwas initially identified in 2021 by the Zwicky Transient Facility as a possible supernova. However, the recurring bursts of light, every 60 to 90 days, have led astronomers to reconsider their nature. According to researcher Lorena Hernández-García, these black holes, separated by approximately 25.749 million kilometers and having a combined mass of 40 million solesgenerate light patterns due to the gravitational disturbance of the gas cloud that surrounds them.
This gas fragments into dense and hot regionsemitting intense variations of light in the ultraviolet spectrum and x-raysmonitored by NASA’s Swift Observatory. Most intriguingly, the host galaxy is merging with another nearby galaxy, which could influence the galaxy’s evolution. movements of black holes and offer new perspectives on the evolution of galaxies. This study not only expands the understanding of black hole life cycles, but also opens the door to discovering how they interact with their environment and the role they play in the evolution of black holes. formation of the universe.
Phenomenon AT 2021hdr
In recent years, technological advances in sky observation have made it possible identify rare astronomical phenomenaknown as exotic transient nuclear events. One of the most notable is the AT 2021hdr, an event associated with a supermassive black hole binary system which interacts with a gas cloud, according to a study published in the journal Astronomy and astrophysics by scientists from the Institute of Astrophysics of Andalusia (IAA-CSIC) and collaborators.
At 2021hdr, located 1 billion light years away in the galaxy Seyfert 1 2MASX J21240027+3409114initially showed constant brightness. However, in mid-2021, it began to exhibit periodic, oscillating peaks in brightness. This behavior was detected by the Zwicky Transient Facility (ZTF) project and confirmed by NASA’s Neil Gehrels Swift Observatory.
The most plausible explanation, according to Lorena Hernández-García, head of the study and scientist at Millennium Institute of Astrophysics (MAS)This is because black holes are surrounded by a cloud of gas that revolves around them. When they interact with it, the forces of gravity and tide break it down and heat it, generating an oscillatory pattern in the light emitted by the system.
Unique Features
The team used observations with the ALFOSC instrument to confirm that the galaxy hosts a Typical active core of Seyfert 1characterized by its constant luminosity in the spectral lines, which excludes the hypothesis of a galaxy with changing appearance. In contrast, the oscillations of ultraviolet light and X-rays detected by Swift coincide with the visible brightness peaks observed by the ZTF, thus strengthening the proposed model.
The phenomenon was reported as potentially interesting by ALeRCE (Machine Learning for Rapid Event Classification)a system that uses artificial intelligence to process large volumes of astronomical data. This tool has been crucial in identifying and classifying transient events like AT 2021hdr.
Initially, it was considered that AT 2021hdr could be a supernova or a tidal disruption event (destruction of a star)but the characteristics of the explosions lead us to consider the interaction with a gas cloud as the most probable explanation. The black holes, which orbit each other every 130 days and contain a combined mass of 40 million suns, could collide and merge in about 70,000 years.
The team will continue to observe the system to better understand its dynamics and refine the physical models. According to Isabel Márquez, vice-director of the IAA-CSIC, studying these events in different wavelengths This is the key to understanding the physical processes involved and their impact on the evolution of galaxies.
Exotic transient nuclear events
Exotic transient nuclear events are brief and rare phenomena in galactic nuclei, usually associated with extreme processes related to supermassive black holes. The most recent example is AT 2021hdr, detected in 2021 in a galaxy a billion light years away, which showed unique periodic light pulses.
This event appears to originate from a binary system of supermassive black holes surrounded by a cloud of gas that emits light when torn apart by gravitational forces. THE periodic oscillation of brightness suggests dynamic interactions between black holes and their environment.
Advanced tools such as the Zwicky Transient Facility and the ALeRCE system, which uses artificial intelligence, have played a key role in identifying and studying this phenomenon. Additionally, observatories such as Swift and optical telescopes have contributed to the analysis of several wavelengths (x-ray, ultraviolet and visible).
The study of these events provides information on binary black hole systemsits impact on galactic evolution and the dynamics of gravitational interactions. Future research aims to monitor similar events, thereby advancing the understanding of extreme nuclear processes in the universe.
