New research may bring bad news to scientists, who think they have discovered a “missing link” black hole in a dense galaxy cluster.
New discovery means, rather than a rare medium quality black holea black hole cluster with a stellar mass centaur omegabelieved to be the cannibalized remains of an ancient galaxy Milky Way.
“The search for elusive intermediate-mass black holes continues,” said team member Justin Reid, a scientist at the University of Surrey in the United Kingdom. “There may still be one at the center of Omega Centauri, but our research shows that it must be less than 6,000 times larger. mass of the sun And living with a swarm of stellar-mass black holes.
astronomer is Reported first When they noticed that some of these stars were moving faster than expected, they discovered that there might be a black hole in Omega Centauri, which contains an estimated 10 million stars.
Related: Elusive mid-sized black holes may form in dense ‘birth nests’
Last year, a group of astronomers Hubble Space Telescope and believe they have discovered an intermediate-mass black hole, with a mass equivalent to about 8,200 suns.
However, reanalysis of the cluster suggests that this may not be the case.
Why are ‘missing link’ black holes important?
As the name suggests, intermediate-mass black holes are somewhere between stellar-mass black holes (with masses between 10 and 1,000 solar masses) and supermassive black holes at the centers of galaxies (with masses equivalent to millions or even billions of suns).
As we all know, the discovery of intermediate-mass black holes so close to Earth is exciting because these black holes are considered key links in the universe. The merger chain that helps black holes reach supermassive stateshas always been notoriously elusive. Although scientists believe they should be common in universe.
This is because, like all black holes, they are surrounded by a one-way light-trapping surface called an event horizon. This means that black holes can only be seen when they are surrounded by the material they grew on, which is heated by tidal forces to produce bright light.
Intermediate black holes are thought to be “stagnant” or “frozen in time” because of the lack of gas and dust around them to absorb. This also means that they are effectively invisible, since the only way to infer their presence is the effect of their gravity on surrounding stars.
It is thought that gravitational interactions with the intermediate-mass black hole at the center of Omega Centauri accelerate the stars at the center of this dense cluster to high speeds.
“We knew early on supermassive black hole at the center of galaxies and smaller stellar-mass black holes within our own galaxy,” team member Andres Bañares Hernandez, a researcher at the Canary Institute of Astronomy, said in a statement.
“However, the idea that intermediate-mass black holes could bridge the gap between these extremes has not yet been proven,” he added. “By studying Omega Centauri—a dwarf galaxy – We have been able to improve our methods and take a step forward in understanding whether such black holes exist and what role they might play in the evolution of star clusters and galaxies.
“This work helps resolve a two-decade-long debate and opens new doors for future exploration.”
Another possible explanation for the observed stellar velocities is a population of stellar-mass black holes that are expected to compact star cluster Like this.
However, astronomers believe that interactions with other stars could “eject” these smaller black holes out of the system. That made an intermediate-mass black hole the most likely explanation for the high-velocity star at the center of Omega Centauri—until now.
In the new study, the researchers took another important source into account when considering Omega Centauri, which changes the picture significantly.
Keep time with the cosmic lighthouse
Additional data comes from a project called “Cosmic Lighthouse” pulsar.
Pulsars are rapidly spinning cosmic remnants called neutron star This structure forms when a massive star runs out of fuel and collapses under its own gravity.
As these dead stars spin at 700 times per second, they also spew beams of radiation from their poles. These beams sweep across the universe like light from the universe Cosmic lighthouse.
as they rotate to point Earththe pulsars brighten, making them appear to be pulsing. Because such pseudopulses are highly periodic when considered in what scientists call a “whole body.” Pulsar Timing Arraythese cosmic beacons are transformed into highly precise timekeeping tools.
Variations in pulsar time can reveal the presence of strong gravitational fields that accelerate these dying stars. The addition of pulsar data allowed the team to detect the gravitational field at the center of Omega Centauri in greater detail.
This allowed the team to distinguish the effects of intermediate black holes and clusters of stellar-mass black holes. The team determined that the latter was the most likely explanation for the speed of the star at the center of Omega Centauri.
The team wasn’t too dismayed by their findings. Reed believes it’s only a matter of time before astronomers start discovering intermediate-mass black holes.
“There’s a good chance we’ll find one [an intermediate-mass black hole] Very quickly,” Reed said. “More and more pulsar accelerations are coming, allowing us to peer into the centers of dense star clusters, Looking for black holes More precise than ever.
At the same time, the team’s research can help astronomers better understand the birth mechanism of pulsars.
“this The formation of pulsars Hernandez concludes: “Omega Centauri is also an active area of research, as large numbers of them have been detected recently. Omega Centauri is an ideal environment to study models of their formation, which for the first time we have been able to do in our space at this point.
The team’s research has been accepted for publication in the journal Astronomy and Astrophysics.