Three black holes that are about to merge - researchers found this rare phenomenon with the help of a trick. Now they hope to find more black hole systems.
Astronomers have discovered three gigantic black holes that are on a collision course. Numerous observations with different telescopes were necessary to track down the rare phenomenon. "Double and triple black holes are extremely rare," explains Shobita Satyapal, co-author of a specialist publication that appears in The Astrophysical Journal. "We were just looking for pairs of black holes and our selection technique stumbled across this amazing system," said Ryan Pfeifle of George Mason University in Fairfax, Virginia, another author of the paper.
The system in which the three black holes are located bears the complicated name SDSS J084905.51 + 111447.2. It is one billion light years from Earth - the black holes are between 10,000 and 30,000 light years apart. The system was not that easy to discover - partly because it is enveloped in gas and dust. This blocks most of the light it produces.
Researchers are looking at a black hole with an infrared and X-ray telescope
To work around this problem, the researchers mainly used infrared and X-ray images. Both types of radiation penetrate the gas clouds more easily than optical light. The researchers used several telescopes, some of which are on Earth and some in space, for their work. First, the "Sloan Digital Sky Survey" telescope (SDSS) in New Mexico scanned a large part of the sky in optical light and discovered the system, consisting of three galaxies with three super massive black holes. In the online project "Galaxy Zoo", citizen scientists identified the celestial object as a system of colliding galaxies.
The NASA “WISE” space telescope was then used: It observed the galaxy system in the infrared range. From the images, the researchers could see that the system was very glowing - in a phase of galaxy merging in which several of the black holes were to swallow up a lot of matter.
"Chandra" shows sources of X-rays - black hole devours matter
Next, NASA's "Chandra" X-ray telescope helped: "Chandra" showed sources of X-rays - a sign that the black holes were devouring material from their surroundings. The sources of the X-rays were in the centers of the three galaxies - exactly where the supermassive black holes should be, according to the researchers' expectations.
In the optical light spectrum of the galaxy system, the researchers found characteristic signatures that the three black holes devour material. "Optical spectra contain a lot of information about a galaxy," says Christina Manzano-King, another co-author of the paper (pre-release). "They are commonly used to identify actively expanding supermassive black holes."
A new way to identify triple supermassive black holes
Pfeifle is pleased: "We have found a new way to identify triple supermassive black holes." Now the researchers hope that they can expand their technology to find more triple black hole systems. Double and triple black holes are very rare, emphasizes co-author Satyapal. "Such systems are a natural consequence of galaxy mergers." The researchers believe that galaxies grow and develop through mergers, as Satyapal explains.
Three black holes behave differently in a merging process than two merging black holes. If there are three objects, two of them should fuse together faster than if the two were alone, astronomers suspect. The influence of the third black hole ultimately brings the two black holes together based on these assumptions.
When black holes merge, gravitational waves arise
The merging of two super massive black holes produces so-called
gravitational waves
*. In the case of SDSS J084905.51 + 111447.2 they would not necessarily be from
gravitational waves
* -Detectors such as LIGO or "Virgo" collected because they have significantly lower frequencies than the detectors can collect. Future space telescopes such as the "Laser Interferometer Space Antenna" (
LISA
*) The European space agency Esa may be able to do so, it says in a message from the "Chandra" X-Ray Center.
Black holes - current research
There is also a black hole in the center of the Milky Way. This has been known for years, but researchers have recently noticed that the black hole Sagittarius A * shone brighter than ever before. Since then, astronomers have been wondering why it suddenly developed a great appetite. A stellar black hole with 70 solar masses * - actually it shouldn't exist. In addition, researchers from Germany have discovered the most massive black hole to date. Astronomers have also identified a source of black hole food in the early universe.
Scientists have also been able to observe almost from the start how a black hole tears a star apart *. In spring, researchers showed the image of a black hole * for the first time.
Look into the universe
"Pale Blue Dot" - the famous picture that shows the earth from the perspective of "Voyager 1" is 30 years old.
Researchers recently published a speculative theory: Is “Planet 9” in our solar system really a small black hole? And what actually happens when researchers find life on Mars? We are not prepared for this, believes Nasa chief scientist Jim Green.
What is going on with the star Betelgeuse in the constellation Orion? It loses massive brightness - does Betelgeuse stand in front of a supernova? * Phosphorus is an essential building block of life on earth. But how did he get to the blue planet? Astronomers have found an explanation for how phosphorus came to earth.
What's going on in the HD101584 star system? On
brutal starfighting
gives researchers a unique insight.
Space probe from Esa and Nasa:
"Solar Orbiter" is supposed to explore the sun
By Tanja Banner
* fr.de is part of the nationwide Ippen-Digital central editorial office.
