Black holes are one of the most frightening anddestructive forces in the universe, but some scientists suggest that the radiation of these objects, which they create during the absorption of surrounding matter, may contribute to the emergence of biomolecular structural elements of life and even stimulate photosynthesis. On a general scale, this may mean that there may be many more worlds capable of supporting life in our galaxy than our current hypotheses suggest.
For your new research, the resultsrecently published in the Astrophysical Journal, astrophysicists have created computer models to study in more detail the specifics of radiation disks made of gas and dust, called active galactic nuclei (AGNs), which rotate around supermassive black holes. Being one of the brightest objects in the Universe, they are formed as a result of the curvature of matter by the gravity of a black hole. This process is accompanied by the release of large amounts of energy.
From the beginning of the 80s there was an opinion among scientiststhat the radiation of these objects creates a dead zone around the active galactic nuclei. Some researchers even suggested that the AGNs are the reason why we have not yet discovered complex forms of extraterrestrial life, in particular, towards the center of our galaxy. In the center of the Milky Way is a huge black gift Sagittarius A *. According to the findings of previous studies, any Earth-like planet, which will be located within a radius of 3200 light years from the center of the active galaxy core, under the influence of powerful X-ray and ultraviolet radiation of AGN will not be able to preserve its atmosphere.
"People most often talk only about destructiveblack hole effects. As part of our research, we wanted to take a fresh look at these effects, in particular, the radiation of black holes, and try to find some positive aspects in them, ”says the head of the research, astronomer at Harvard University, Manaswi Lingam.
Is life possible near black holes?
Computer models created by researchersshowed that planets with an atmosphere at a density comparable to that of the Earth and higher, and being far enough away from AGNs, will be able to preserve their atmospheres and, moreover, will be able to maintain life on their surface. Scientists explain that at a certain distance from the center of AGNs, the latter, like the stars, have so-called “habitable zones”, where the amount of ultraviolet radiation is not so high as to destroy all life that may be there.
With such levels of radiation, scientists saythe atmospheres of the planets will not collapse. At the same time, this radiation will be able to break down the molecules, creating the compounds necessary to produce the structural elements - proteins, lipids and DNA - necessary at least for the life that we know. For black holes the size of the same Sagittarius A *, which is located in the center of our galaxy, the “habitable zone” will begin approximately 140 light years from the center of the black hole (1 light year = 150 million kilometers), the researchers say. At the same time, the negative effects of its radiation will be significantly reduced already within a radius of 100 light years from the center of AGNs.
Black holes and photosynthesis. What do they have in common?
Scientists also looked at exposure effects.This radiation on photosynthesis - the process of synthesis of organic substances from inorganic due to the energy of light through which plants produce oxygen, and some types of bacteria and algae also glucose. As noted above, AGNs are capable of emitting huge amounts of the key element required for photosynthesis - light. According to Manaswi, this aspect would be especially important for the so-called orphan planets, objects that have a mass comparable to the planetary and spherical shape and are essentially planets, but not attached gravitationally to any star. According to scientists, about 1 billion of such wandering planets can be in the “habitable zone” of galaxies the size of our Milky Way.
By calculating the area on which the AGN will be capableto support photosynthesis, scientists have discovered that a huge number of galaxies, in particular those with supermassive black holes located in their centers, will be able to support this kind of photosynthesis. For example, for a galaxy the size of ours, this region will occupy about 1,100 light years around its center. As for small and more dense, so-called ultracompact dwarf galaxies, more than half of their area will be suitable for photosynthesis, the scientists note.
With a fresh look at x-ray andultraviolet radiation, the researchers say, is becoming clear that in the past the negative effects of AGNs have been significantly exaggerated. Scientists explain that many species of the same terrestrial bacteria are able to create around themselves a special biofilm that protects them from ultraviolet radiation, so one should not exclude the possibility that life in areas of space with an increased radiation background could also adapt to similar survival methods.
The new study also states thatX-ray and gamma radiation, which is also actively emitted by AGN in large quantities, will be easily absorbed by the Earth-like atmosphere of exoplanets and, apparently, will not have a significant impact on the life forms that can inhabit them.
As for the AGNS of our galaxy, then according to the researchers, the negative effects of its radiation will be significantly reduced already within a radius of 100 light years from the center of the AGN.
"If you look at our Earth as an example,then we can safely assume that the positive effects of radiation can exceed its negative effects. For us, this discovery also turned out to be a real revelation, ”Lingam sums up.
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