Astrophysics

Two pairs of quasars in the early universe Astrophysics

Two pairs of quasars in the early universe

Quasars are loners. This is not because they do not get along with their colleagues, but has something to do with their nature. They are nuclei of active galaxies. And every galaxy has only one nucleus. Billions of stars can rotate badly around several cores. Nevertheless, astronomers have now found two quasar pairs at a distance of about ten billion light years as they report in Nature Astronomy. (more…)
Even the core of the Milky Way gives birth to stars Astrophysics

Even the core of the Milky Way gives birth to stars

Since Star Trek V we know that the core of the Milky Way is a very special area. There is no galactic barrier there, but there is a gigantic black hole (Sagittarius A*) with the fields it produces and a lot of stars in a small space. With average distances of less than one light year the night sky of a planet must be very bright there. New stars are formed from clusters of gas and dust clouds. The process is disturbed when magnetic fields waft through it or passing stars deform the cloud with their gravitational pull. In…
The very first structures of the cosmos Astrophysics

The very first structures of the cosmos

In one of my newest books astronomers are trying to use a solar gravitational lens to look at the beginning of the universe. Whether they succeed, I will not reveal here. But physicists at the Universities of Göttingen and Auckland (New Zealand) have now determined what they would see with the help of greatly improved computer simulations. The scientists discovered that a complex network of structures can form in the first trillionth of a second after the Big Bang. But these are not just any random structures: the behavior of these objects already mimics the distribution of galaxies in…
Basic structure of the cosmos pictured for the first time Astrophysics

Basic structure of the cosmos pictured for the first time

Stars group together to form galaxies. Galaxies form galaxy clusters. These form superclusters, between which vast, largely empty regions extend, the voids. All superclusters are connected by a honeycomb-like basic structure, the "cosmic web", which consists of filamentary gas structures of hydrogen. That these filaments must exist has been known for some time. On the one hand, they are known from simulations based on theories of the structure of the universe, which predict such a basic structure. On the other hand, they become visible when energetic quasars illuminate them like car headlights illuminating the nebula. However, the regions thus…
News from the warp drive: one problem less Astrophysics

News from the warp drive: one problem less

Sometimes there are strange coincidences. Yesterday I reported here that "passable" wormholes could be realizable also without the addition of negative energy. This is an important advance because there is no natural source for negative energy. The only thing we can do to get a little bit of negative energy is to trick the universe. We take the negative energy from it while it is not looking and give it back before it has even noticed. This gap offers us the uncertainty principle of quantum physics. But in order to obtain negative energy in quantities such as would be…
Quasar transmits from the early days of the universe Astrophysics

Quasar transmits from the early days of the universe

In the 1950s, astronomers discovered radio sources to which point-like, i.e. star-like objects could be assigned in the visible light range. Until then, whole galaxies had been identified as radio sources. The findings were called "quasi-stellar objects", or quasars for short. Later, however, researchers realized that quasars are embedded in galaxies after all, and in fact constitute their active nuclei radiating in many wavelength ranges. That they had been seen only as point sources was simply because they are very, very distant. In fact, they are the most distant objects in the universe that we can observe. This is…
Merging boson stars instead of colliding black holes? Astrophysics

Merging boson stars instead of colliding black holes?

Bosons are particles with an even spin. They include the fundamental particles that mediate the individual interactions (such as photons for electromagnetism), but also composite particles such as helium-4 atoms. Their peculiarity is that any number of them can occupy the same ground state. They are then indistinguishable from each other and form a Bose-Einstein condensate with unusual properties. Among other things, the density of the condensate can approach infinity. This would make bosons good candidates for very heavy celestial bodies, where huge masses crowd into a small space. Who doesn't think of a black hole? But a celestial…
Can supermassive black holes collapse directly from dark matter? Astrophysics

Can supermassive black holes collapse directly from dark matter?

At first glance, a black hole and dark matter sound like a perfect combination. However, there is a problem: dark matter is mainly found in the outer regions of galaxies, in massive halos. Supermassive black holes, on the other hand, form the core of a galaxy. Does there nevertheless go something together, which belongs together? Perhaps. As far as supermassive black holes are concerned, cosmology still has a problem. Because how exactly they originally formed is one of the biggest problems in the study of galaxy evolution today. Supermassive black holes were observed as early as 800 million years…