This discovery could offer the very first proof of a “jet” introduced by a Galactic stellar-mass black hole. Stellar-mass black holes with masses of approximately 10 suns, for example, expose their existence by eating materials from their buddy stars. And in some instances, supermassive black holes collect at the center of some galaxies to form bright compact regions understood as quasars with masses equivalent to millions or even billions of our sun. A subset of accreting stellar-mass black holes that can release jets of extremely allured plasma are called microquasars.
QPOs are a phenomenon that astronomers use to comprehend how stellar systems like black holes function.
Artists depiction of microquasar event captured by FAST Telescope. Credit: Courtesy Professor Wei Wang, Wuhan University
An international group of scientists reports the very first detection of a quasi-periodic oscillation signal in the radio band from a Galactic black hole system.
Using a sophisticated telescope in China, they detected a quasi-periodic oscillation (QPO) signal in the radio band for the very first time in microquasar systems. This discovery might offer the very first evidence of a “jet” launched by a Galactic stellar-mass black hole.
Great voids are among the most mystical objects in the universe, with functions that sound like they come directly from a sci-fi movie.
Stellar-mass black holes with masses of roughly 10 suns, for instance, reveal their existence by eating products from their buddy stars. And in some circumstances, supermassive great voids accumulate at the center of some galaxies to form bright compact regions referred to as quasars with masses equivalent to millions and even billions of our sun. A subset of accreting stellar-mass great voids that can release jets of extremely allured plasma are called microquasars.
An international group of scientists, consisting of University of Nevada, Las Vegas (UNLV) astrophysicist Bing Zhang, reports in the July 26 problem of Nature a dedicated observational project on the Galactic microquasar called GRS 1915 +105. The team exposed features of a microquasar system that have actually never before been seen.
Utilizing the huge Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China, astronomers found a quasi-periodic oscillation (QPO) signal in the radio band for the very first time from any microquasar systems. QPOs are a phenomenon that astronomers usage to comprehend how stellar systems like black holes work. And while they have been observed in X-rays from microquasars, their existence beyond this manner– as part of the systems radio emission– is unique.
” The peculiar QPO signal has a rough period of 0.2 seconds, or a frequency of about 5 Hertz,” said Wei Wang, a professor at Chinas Wuhan University who led the group that made the discovery. “Such a signal does not always exist and only reveals up under special physical conditions. Our team was fortunate sufficient to catch the signal twice– in January 2021 and June 2022, respectively.”
According to UNLVs Zhang, director of the Nevada Center for Astrophysics and among the studys matching authors, this special feature may offer the first evidence of activity from a “jet” launched by a Galactic stellar-mass great void. Under specific conditions, some great void double stars introduce a jet– a mix of parallel beams of charged matter and a magnetic field that moves with a swiftness approaching the speed of light.
” In accreting black hole systems, X-rays usually penetrate the accretion disk around the great void while radio emission typically probes the jet released from the disk and the great void,” stated Zhang. “The comprehensive system to induce temporal modulation in a relativistic jet is not determined, but one plausible mechanism would be that the jet is underlying precession, which implies the jet direction is frequently pointing towards different directions and go back to the initial direction as soon as every about 0.2 seconds.”
Zhang said that a misalignment between the spin axis of the great void and its accretion disk (exceptionally hot, bright spinning gasses surrounding the great void) could cause this result, which is a natural consequence of a dragging of spacetime near a quickly spinning great void.
” Other possibilities exist, though, and continued observations of this and other Galactic microquasar sources will bring more ideas to understand these strange QPO signals,” stated Zhang.
Recommendation: “Sub-second periodic radio oscillation in a microquasar” by Pengfu Tian, Ping Zhang, Wei Wang, Pei Wang, Xiaohui Sun, Jifeng Liu, Bing Zhang, Zigao Dai, Feng Yuan, Shuangnan Zhang, Qingzhong Liu, Peng Jiang, Xuefeng Wu, Zheng Zheng, Jiashi Chen, Di Li, Zonghong Zhu, Zhichen Pan, Hengqian Gan, Xiao Chen & & Na Sai, 26 July 2023, Nature.DOI: 10.1038/ s41586-023-06336-6.
The publication includes 21 co-authors from 13 organizations. UNLV and Wuhan University, other institutions include National Astronomical Observatories of China (NAOC) and a number of other observatories and universities from China.
