Image from ESA
Stars were thought to be the principal and most important component for life to thrive… till now. Researchers from Harvard university explain that radiation coming from Black holes could do the same!
Habitable zones in outer space have been defined with respect to stars (suns), as regions where the stars radiation and energy are suitable for emergence of life. Closer or farther away from this source of energy, temperature would be too cold or too hot in order for liquid water to exist in a planet´s surface. The zones were liquid water and biological opportunity can happen are known as “Goldilocks zone”.
A new study published in The Astrophysical Journal have found such zones around supermassive black holes as well. This is quite surprising, since the surroundings of a black hole, consisting on swirling disks of gas and dust called Active Galactic Nuclei -AGN-, emit enormous amounts of radiation (mainly x-ray, gamma and ultraviolet light) that could destroy nearby planets´ atmospheres, creating a dead zone around the BH.
After numerical simulations using programs that model AGNs, researchers were able to identify such regions around the BHs and concluded that the destruction regime was highly overestimated. For instance, the damaging zone is located 100 light years away, a much shorter distance than the 3,200 light years predicted by former studies for Sagittarius A* -Milky ways´ supermassive BH-. Meanwhile, its Goldilocks region extends 140 light years from the black hole center.
Being the dangerous distance of the AGN region narrower than the total extension of the AGN zone, if placed within the remaining AGN region, a planet´s atmosphere could remain intact while at the same time the radiation of the active nuclei could break molecules to create the biological building blocks which are lipids, proteins and DNA. For a galaxy as our own, the AGN-powered photosynthesis region would extend up to 1,100 light-years out from the center of the galaxy. At the same time, light emanating from the AGN could facilitate photosynthesis, a particularly important fact for free floating planets believed to have no source of light energy around them.
“Astronomers have estimated there could be around 1 billion such rogue planets drifting in the Goldilocks zone of a Milky Way-like galaxy”
according to Manasvi.
Concerning the damaging effects of the ultraviolet and X-ray radiation in these zones, the scientists claim that bacteria on Earth created biofilms to protect themselves from ultraviolet rays, and that X-rays and gamma-rays are also readily absorbed by Earth-like atmospheres, reducing considerably their impact.
RSF in perspective:Like the recently discovered AGN goldilocks zone, astrophysicist had already re-evaluated and extended the habitability zone due to M type stars. The increase in habitability keeps growing, which implies an exponential probability of life in outer space and therefore a high probability for intelligent life. We are most probably not alone in the galaxy. On the other hand, if black holes are so directly related to suns, wouldn´t the other direction apply? Wouldn´t suns behave or be white holes?