Gc 1277 is part of the perseus galaxy cluster, which is with a distance of 250 million light-years one of the most earth-nearest galaxy clusters. All the elliptical and roundish yellowish galaxies visible in this image are part of the cluster. Compared to the other cluster members ngc 1277 is comparatively compact. Image: david w. Hogg, michael blanton and the sdss collaboration
More and more massive black holes are discovered
Black holes fascinate astronomers as well as the general public. Spectacularly they are born from dying massive stars, and like vacuum cleaners they pull everything from the surroundings into their black maw. They are regions of space-time that devour everything that comes too close to them. Not even a single ray of light can escape them. What comes to the edge of the devouring monsters disappears never to be seen again beyond their event horizon.
Matter and light swirl around it in a vortex, then finally disappear from space. There are different types of black holes, but the theories – especially about their origin – are still being debated. Two recent discoveries now provide new material for the scientific debate.
Already at the end of the 18. In the nineteenth century, researchers speculated about the idea of "dark stars". However, the term black hole was first pragmatized by the us physicist john wheeler in the late 1960s.
The gigantic cosmic gravity traps are the subject of intensive research and still cause a lot of controversy today. The models of its development are particularly controversial . A generally accepted, minimal definition comes from stephen hawking:
Black hole: region of space-time from which nothing, not even light, can escape because gravity is so strong.
In the current ie of the science magazine nature, a german-american team of scientists led by remco van den bosch of the max planck institute for astronomy in heidelberg reports on what may be the most gigantic black hole ever discovered.
Astronomers tracked it down in the central region of the disk galaxy known as ngc 1277 in the perseus galaxy cluster, which is 250 million light-years from earth. This region of space had already produced headlines a few years ago because a black hole located there produces the deepest sound known so far in the universe: it hums 57 octaves below middle c .
The astronomers now observed the region again using the hobby-eberly telescope at the mcdonald observatory in texas, and then compared the data with archived images from the hubble space telescope. The results are spectacular: they discovered a giant black hole of 17 billion solar masses that is much coarser in relation to its relatively small home galaxy than the models suggest. It accounts for 14 percent of the total mass of the disk galaxy ngc 1277 (which is about 120 billion solar masses)!
Moreover, it could be the largest black hole ever tracked down – the exact weight of the previous record holder is still being debated.
Image of the disk galaxy ngc 1277 taken with the hubble space telescope. The center of this small, flattened galaxy contains one of the most massive black holes ever found. Image: nasa / esa / andrew c. Fabian / remco c. E. Van den bosch (mpia)
The state of the art is that in the center of every galaxy there is a supermassive black hole, even in the milky way – here it is called sagittarius a and has about four million solar masses.
Measured in terms of the at least 180 billion solar masses clustered in our galaxy, it is consistent with current models, which typically put the weight of each central black monster in a galaxy at a tiny fraction – about 0.1 percent – of the total mass of all the stars in it.
Co-author karl gebhard of the university of texas at austin explains the new discovery:
The mass of this black hole is much coarser than expected. This finding brings us to the consideration that black holes in very massive galaxies grow in a different physical process. If you want to understand something, you always look at the extremes: the most massive and the lightest black holes. We observe therefore a rough selection of particularly massive galaxies in the nearer cosmic environment.
It is conceivable that the dark maw in the middle of ngc 1277 is swollen to this size by the collision of two galaxies or the merging with another black hole. The only thing that is clear so far is that the theories of how galaxies (and their central gravitational traps) form and evolve need to be tested. Remco van den bosch opines:
At the moment there are three completely different models to explain the connection between the mass of the black hole and the properties of the galaxy. Up to now it is still unclear, which theoretical approach of it will become generally accepted.
The team already has its eye on five other galaxies whose central black holes also appear to be unusually huge. Astronomers will now observe these stellar formations in detail with suitable coarse telescopes.
Violent rippling of a black hole
At the same time, news comes from the european southern observatory (eso) that a team of astronomers using the very large telescope in chile (vlt) has made an equally spectacular discovery: the strongest stream of matter ever measured being ejected by a black hole. In an advance publication they report on the flow of matter. The article will be published in the astrophysical journal.
The group around benoit borguet of the virginia tech in the american blacksburg spahte the quasar with the catalog number sdss j1106+1939 and discovered thereby the gigantic flow of matter. Quasi-stellar radio sources, called quasars for short, are young galaxies with extremely luminous cores that host supermassive and active black holes at their centers.
The matter streams coming from these central monsters are essential for the evolution of the galaxies. But the astronomers despaired slowly at their theories, because the so far observed quasars eject clearly less matter, than predicted by the models. This has now changed abruptly, because sdss j1106+1939 is flowing at least five times as strongly as all other known quasars. Exactly as predicted by theory.
Artistic representation of the gigantic matter fluxes of the quasar sdss j1106+1939; image: eso
The matter stream has been estimated to be about 1.The first spacecraft to be spun up at a distance of 000 light-years from the supermassive black hole at the heart of the quasar sdss j1106+1939. Data from benoit borguet’s team showed that the quasar blows out material on the order of about 400 solar masses every year at a speed of 8000 kilometers per second. Co-author nahum arav of virginia tech explains:
We have discovered the strongest quasar matter flux of all times. Sdss j1106+1939 carries away two trillion times the total power of the sun in the form of matter at high velocities. This corresponds to one hundred times the radiation of the entire milky way – a truly gigantic energy outpouring. This is the first time we have measured a quasar matter flux that shows energy levels as high as predicted by theory. We have been looking for something like this for ten years. It’s incredibly exciting to have found one of these long-predicted monster matter flows!