Black hole

Gas bubble chases around core of Milky Way Astrophysics

Gas bubble chases around core of Milky Way

Astronomers have discovered a hot gas bubble rotating clockwise around the black hole Sagittarius A* - the core of our Galaxy. However, this bubble has not been found directly, but via an accompanying phenomenon: flares in the X-ray range, which have been detected again and again, starting from the black hole Sgr A*. Since nothing can leave the black hole itself, a phenomenon in the immediate vicinity must be responsible - the gas bubble. (more…)
Black hole winds are no longer what they used to be Astrophysics

Black hole winds are no longer what they used to be

In the early times of the universe, black holes in the centers of active galaxies grew much faster than today. Only in this way it can be explained that 500 to thousand million years after the big bang there were already such huge black holes. Today, however, things look different - the black holes at the centers are evolving in parallel with their host galaxies. When and why did this change occur? That's what a study led by three researchers from Italy's National Institute of Astrophysics (INAF) in Trieste has found, published in the journal Nature. The work is…
Fast growing black hole discovered Astrophysics

Fast growing black hole discovered

Astronomers have known for a while that the centers of most galaxies are home to supermassive black holes. With ever-improving methods of investigation, they have been able to trace these giants far back into the past. They must have existed as early as 750 million years after the Big Bang. This raises one of the biggest mysteries in astronomy today: How could these supermassive black holes, which weigh millions to billions of times the mass of the Sun, grow so large so quickly? Current theories hold that supermassive black holes begin their lives in the dust-shrouded cores of galaxies…
When the universe began to boil Astrophysics

When the universe began to boil

How did the supermassive black holes come into being, which today are gigantic sentinels in the center of many galaxies? Initially, one proceeded from the obvious: The giants grew by accreting other matter or consuming black holes, that is, by merging with them. Step by step, from small to medium to giant. But this concept has a couple of problems. First, we have not yet been able to detect the necessary intermediate stages. They should still exist, but so far we have only found small black holes - or the really big ones. Problem number 2 is that there…
How many black holes are there in the universe? Astrophysics

How many black holes are there in the universe?

A lot. If a star is heavy enough (i.e., it is still at least 2.5 solar masses after its supernova), then it continues to collapse until a black hole forms. Such stellar-sized black holes have been forming for quite some time, and more and more are forming. How many are there already? This intriguing question has been addressed by Alex Sicilia, a PhD student under the supervision of Prof. Andrea Lapi and Dr. Lumen Boco of Italy's Scuola Internazionale Superiore di Studi Avanzati. In a first paper just published in the Astrophysical Journal, the authors studied the demography of…
What does a black hole look like from the inside? Astrophysics

What does a black hole look like from the inside?

A black hole is an amazing phenomenon. It is invisible because it does not even allow light to escape. Nevertheless, it can be imaged. It concentrates mass in a very small part of space - so small that the conventional laws of physics lose their meaning. Nevertheless, physicists are getting closer and closer to its secrets. One of them is what a black hole looks like inside. Black, it is clear, is not there. Quite the opposite. Inside, all the mass and energy that cannot escape the event horizon are concentrated. If one could see in a black hole,…
Black holes on a collision course Space

Black holes on a collision course

Do you already have something planned for the year 250,002,000? Then take an evening off and look with your future super telescopic eye at the area around the galaxy NGC 7727 in the constellation Aquarius. There, two super heavy black holes are colliding with each other. Today, they are still 1600 light-years apart, but they are the closest pair of black holes observed so far. Astronomers found it with the help of the European Southern Observatory's VLT. "It is the first time we have found two supermassive black holes so close together, less than half the distance of the previous…
The great barrier is real – for cosmic rays Astrophysics

The great barrier is real – for cosmic rays

The great barrier surrounding the core of the Milky Way is encountered in 2287 by the starship NCC-1701-A under the command of Captain James T. Kirk. Supposedly, it is impenetrable, and any ship that nevertheless dares to cross it will be destroyed. Kirk and his squad from the USS Enterprise prove the legend to be false. In fact, there is a kind of barrier around the galactic center - and this barrier is not an impenetrable wall. But, as astronomers have now discovered, it is an obstacle to cosmic rays. (more…)