An artist’s impression of a flare body sending jets of energetic particles toward Earth. (NASA/JPL-Caltech)
[The Epoch Times, April 5, 2023](The Epoch Times reporter Linda compiled a report) An international team of astronomers discovered that the black hole at the center of a galaxy suddenly changed the direction of its jet and pointed it directly at the Earth.
The galaxy, named PBC J2333.9-2343, is more than 656 million light-years away from Earth and is now classified by astronomers as a Giant Radio Galaxy (Giant Radio Galaxy), with a flare star at its core. A blazar is a type of galaxy powered by a black hole that shoots a stream of energetic particles toward Earth at nearly the speed of light.
The researchers observed the galaxy across a wide range of the electromagnetic spectrum, including radio, optical, infrared, X-ray, ultraviolet and gamma rays. The galaxy was then compared to a large number of known blazing and non-flareing galaxies.
“We started studying this galaxy because it displayed unusual properties,” said lead author Lorena Hernández, a researcher at the Millennium Institute of Astrophysics. -García) explained.
In this galaxy, the jets originate from a supermassive black hole near its center. “As the jets point in the direction of Earth, the intensity of the radiation increases greatly, easily outpacing radiation from other parts of the galaxy. This in turn drives high-intensity flares that are stronger than flares from other radio galaxies, changing their classification. ” said the Royal Astronomical Society in a press release. Astronomers therefore changed the galaxy’s classification from the previous radio galaxy to a giant radio galaxy.
The direction of the jets helps determine how galaxies are classified. When there are jets ejected vertically from the core of the galaxy, it is called a quasar (Quasar). With both a set of jets coming out in parallel and another jet heading towards Earth, the galaxy is reclassified as a radio galaxy with a central blazing star.
While scientists aren’t sure what caused the jet to change direction, they speculate it could be due to a merger event with another galaxy or other relatively large object, or a violent outburst of the galaxy’s nucleus after a dormant period.
The research paper was published March 20 in Monthly Notices of the Royal Astronomical Society. ◇
Responsible Editor: Ye Ziwei#