Galaxy: Black hole, you have no moral principles!

Recently, a team of astronomers

A unique black hole discovered

This black hole is heading towards another galaxy

Spraying 440,000 light-years-long "saliva"

This news became a hot search

Many netizens expressed doubts

Can't black holes swallow everything?

How can you still "spit"?

The mystery of scarce star formation in elliptical galaxies

If stars are the inhabitants of the universe, then galaxies are the villages or cities of the universe. Based on their different morphologies, galaxies are mainly divided into three categories: elliptical galaxies, spiral galaxies, and irregular galaxies. Spiral galaxies have a lot of cold gas and dust, and have spiral arms that appear optically blue. In spiral galaxies, on average, one star similar to the Sun is formed every year. On the other hand, elliptical galaxies are yellow in color and lack distinctive features like spiral arms.

Image source: Baidu Encyclopedia Elliptical Galaxy

Image source: Baidu Encyclopedia Spiral Galaxy

Just as the population is not evenly distributed across the Earth's surface, these cosmic cities and villages are also unevenly distributed. In spiral galaxies, an average of one star similar to our Sun is formed every year. But in the elliptical galaxies we see today, no stars have been formed for billions of years. Why is star formation so rare in elliptical galaxies? This has long been a mystery to scientists.

Is the “spitting” black hole the “murderer”?

A team of astronomers, with the help of citizen scientists, discovered this unique black hole is spitting fiery jets at another galaxy, which are traveling at extremely high speeds through the galaxy, depleting it of cool gas and dust needed for future star formation.

Image credit: Dr. Ananda Hota, GMRT, CFHT, MeerKAT

This suggests that these big spitting black holes may be the culprit for the very scarce star formation in elliptical galaxies.

The black hole is located in the RAD12 galaxy, which is about 1 billion light-years from Earth. The black hole in RAD12 appears to have ejected jets into only one neighboring galaxy, which has been named RAD12-B. In all cases, the jets were ejected in pairs, moving in opposite directions at relativistic speeds. Why only one jet was seen coming from RAD12 remains a mystery to astronomers.

Can black holes spray things?!

The Tulip Nebula, numbered Sh2-101

Image source and copyright: Peter Kohlmann

This nebula emits a reddish glow

Common name: Tulip Nebula

Interstellar gas and dust make up

Red petals

They are influenced by nearby young stars.

Glowing under ultraviolet light

The small curved leaf on the right side of the flower

It is a masterpiece formed by the impact of the black hole jet.

The central jet of the black hole at the center of the Centaurus A galaxy as analyzed by the Event Horizon Telescope

Image source: Radboud University; CSIRO/ATNF/I. Feain et al., R. Morganti et al., N. Junkes et al.; ESO/WFI; MPIfR/ESO/APEX/A. Weiss et al.; NASA/CXC/CfA/R. Kraft et al.; TANAMI/C. Mueller et al.; EHT/M. Janssen et al.

Black holes are known for being voracious eaters, but they don't eat everything that falls to them. A small portion of the matter is ejected in powerful jets of hot gas called plasma, wreaking havoc on its surroundings. Along the way, this plasma somehow gains enough energy to glow intensely, forming two bright pillars along the black hole's axis of rotation. Scientists have long debated where and how this process occurs in the jets.

The jet of a black hole is closely related to the gas around the black hole. In order to produce a jet, there must be enough gas around the black hole to form a gas disk. Finally, if the conditions are right, part of the gas will be ejected along the axis of the black hole before falling into the black hole, forming a jet. Therefore, jets are only produced under specific circumstances. In the universe, only about 10% of supermassive black holes will produce black hole jets.

END

Source: China National Astronomical Institute, Beijing Planetarium

National Space Science Center, CNBeta, Xinjiang Science and Technology Museum

Compiled by: Dong Xiaoxian

Editor: Guru