In the universe, this black hole has disappeared, and astronomers are full of controversy

Introduction: Astronomers are looking for the traces of pearls one by one. This black hole should be located in the center of a galaxy 27 million light-years away from the earth. The motion and huge mass of surrounding celestial bodies indicate that there should be a supermassive black hole in its center. However, several data collection methods such as Hubble and Chandra Telescope have been used to find the location of this black hole. It is speculated that there are two possibilities. One is that there is not enough material around the black hole to swallow it, so it cannot be perceived. Gravitational waves from the merger of massive black holes push black holes that should be in the middle of galaxies out into outer space.

Astronomers are looking for a missing cosmic creature. The quarry is dark and unforgiving, clocked at about 100 billion times the mass of the sun.

Over the years, scientists have observed a large galaxy 2.7 billion light-years from Earth. From every data point they collected, there was clear evidence of a massive black hole lurking at the center of the Milky Way, like our own. But while scientists are adamant that black holes exist, they haven't been able to find them. No trace.

But they're getting closer to solving this huge mystery. Using a new set of data, a team of researchers has been able to locate the potential whereabouts of the missing black hole, allowing them to construct scenarios to explain where the behemoth might be hiding.

Kayhan Gultekin, a professor in the Department of Astronomy at the University of Michigan, is the lead author of the new study, which details these conditions. He told Inverse he's absolutely sure black holes exist - and he's determined to find them.

"It's there, it's hard to find," Gultkin said.

Gultekin and colleagues' work is detailed in a study posted to the online preprint server arXiv. Although not peer-reviewed, the research has been accepted for publication in the Journal of the American Astronomical Society.

The massive elliptical galaxy at the center of this image captured by NASA's Hubble Space Telescope is the largest, most central, and brightest member of the Milky Way, Abell 2261. NASA, ESA, M. Postman (STScI), T. Lauer ( NOAO) and the CLASH group.

A mystery that began in 1999 - astronomers used NASA's Chandra X-ray Observatory to collect observations on a galaxy cluster called Abell 2261. At the center of the cluster is a galaxy that stands out above the rest: Abell 2261-BCG. This galaxy is about ten times larger than our own Milky Way.

It is accepted that galaxies the size of the Milky Way or larger contain a massive black hole at their center. The supermassive black hole at the center of the Milky Way is 3.6 million times the mass of the Sun.

But observations of Abell 2261-BCG did not reveal a black hole at the center of a large galaxy.

Astronomers have been scouring galaxies for missing black holes. NASA/CXC, NASA/STScI, NAOJ/Subaru, NSF/NRAO/VLA

Astronomers made follow-up observations using NASA's Chandra in 2004, followed by images of the galaxy collected using NASA's Hubble Space Telescope and Subaru Telescope, and the National Science Foundation's Carl Jansky Very Large The array telescope made radio emission measurements.

However: still no black holes have been found.

Astronomers aren't disheartened. In 2018, scientists tried Chandra again, taking further X-ray observations of the Milky Way. By imaging the entire galaxy cluster around Abell 2261-BCG, they were able to search for black holes deeper than ever before.

Technically speaking, black holes are difficult to find because they are so dark - light cannot escape from the depths.

Astronomers typically locate black holes based on the motion of their nearby stars, or when they peer out of the black hole for certain bright sparks created by the material they're sucking toward them, forming a series of dust, gas, and Others are called their accretion disks.

But Gultkin said some of these cosmic beasts, despite their large size, are somewhat shy and quiet, which may be the case for the lack of black holes.

In the new study, he and his colleagues narrowed the mystery down to two possible strong explanations:

The first scenario suggests that the black hole at the center of the Milky Way doesn't devour too much material from its surroundings, and therefore doesn't absorb too much.

"So we don't see a secret sign of this," Gultkin said. "If it's really bright, it's going to be easy."

Literally, the second scene is there.

The researchers believe that the black hole's host may have expelled it from the galaxy after it merged with another galaxy. The two black holes of various galaxies will merge together to form a binary black hole.

When two black holes merge, they release powerful ripples in space and time called gravitational waves. The momentum generated by the gravitational waves is powerful enough to completely kick the original black hole out of the galaxy.

This process is called a recoil black hole. Astronomers have theoretically studied these black holes before, but never discovered them.

If it was kicked out of Abell 2261-BCG, the lost black hole could be floating aimlessly through space, perhaps surrounded by a few stars.

If this were the case, then finding the missing black hole would simply be impossible. This will always be a mystery to us.

Abstract: We used Chandra X-ray observations to find evidence that the brightest galactic galaxy, Abell 2261 (A2261-BCG), has a recoiled black hole. Image observations from the Hubble Space Telescope show that A2261-BCG has a huge flat stellar core, making it ideal for recoil black holes. We performed 100 seconds of observations with Chandra and combined them with 35 seconds of archival observations to look for low-level accumulations in black holes of possible mass M ~ 10 M⊙, which may be located at four eccentricities One of the stellar knots is near the center of the Milky Way, or near the optical center of the Milky Way, or at the location of the radio emission.

We find that no point source produces an X-ray emission that exceeds the cluster gas and can limit the accumulation cm-2 of the 24.3 keV flux (below 4.3 × 10-16 erg s-1) for any black hole in the central region, corresponding to Fallout loves Dington score of about 10-6. Therefore, there is no 1010M⊙ black hole in the core of A2261-BCG, or its accretion level is low. We will also discuss the morphology of the X-ray emitting gas in the cluster and how its asymmetry is consistent with large dynamic events.