There is a growing view that black holes in the early universe may have been the seed around which most large galaxies today (now with a supermassive black hole at their centers ) began to grow. And taking a step back, could also be the case that black holes were the key to reionization of the early interstellar medium - which in turn influenced the large-scale structure of universe today.
To recap the first years ... First came the Big Bang - and for about three minutes it was very compact and therefore very hot - but after three minutes the first protons and electrons formed and the next 17 minutes a proportion of these protons interacted to form helium nuclei - up to 20 minutes after the Big Bang, the expanding universe became too cold to keep the nucleosynthesis . From there, protons, helium nuclei and electrons only ranged over the next 380 thousand years as a very hot plasma.
There were too many photons, but there was little chance that these photons do something other than form and immediately be reabsorbed by a neighboring particle in the hot plasma. But the 380,000 years, the expanding universe cooled enough for protons and helium nuclei combine with electrons to form the first atoms - and suddenly the photons were left with empty space were issued as the first rays of light - which in this day is still possible to detect as CMB .
high-mass binary (with a black hole as one of its components) emit X-rays were probably common in the early universe influencing their subsequent fate being a possible cause of the reionization process that ended the so-called dark age of universo.Credito: ESO.
diagram showing the stages through which has passed the state of baryonic matter from the beginning of the universe (where there ionized plasma) after neutral atoms formed (380,000 years after the bigbang) and then re-reionize (500000 years after big bang) when the first stars formed, this plasma reionised that filled the interstellar medium was completely transparent to radiation and siéndolo.Credito continues: New Scientist.
What followed was the so-called dark ages only to about half a billion years after the Big Bang, the first stars began to form. It is likely that these stars were big, very big, as fresh and stable atoms of hydrogen (and helium) available were added and widened. Some of these first stars may have been so great that quickly blew apart as a supernova unstable pair. Others were simply too big and collapsed into black holes - many of them having too much gravity (itself) to allow a supernova explosion could fly any material from the star.
And here is where the history of reionization begins. Cold atoms and hydrogen stable early interstellar medium not remain cold and stable for long. In a smaller universe full of dense massive stars, these atoms quickly overheated, causing their electrons and nuclei are dissociated into ions became free again. This created a low-density plasma - still very hot, but too diffuse to be opaque to light any longer.
is likely that this step reionization then limited the size at which new stars may grow - and limited opportunities for new galaxies to grow - (as hot and excited ions are less prone to aggregate and enhance the cold and stable atoms .) Reionization may have contributed to the current distribution "lumpy" of matter - which is generally organized in large, discrete galaxies, instead of a uniform dispersion of stars everywhere.
And it has been suggested that the first black holes - in fact the high-mass black holes X-ray binaries - may have made a significant contribution to the reionization of the early universe. Computer models suggest that in the early universe, with a trend toward very massive stars would be much more likely to have black holes and stellar remnants, rather than neutron stars or white dwarfs . Also, those black holes would be more frequently isolated binary (because the most massive stars are most multiple systems often than they do the small stars).
Thus, with a massive binary in which one component is a black hole - black hole quickly start to accumulate a large accretion disk composed of matter from another star. Then the accretion disk will begin issuing high-energy photons in particular in the energy levels of X-rays.
Although the number of ionizing photons emitted by an accreting black hole is probably similar to its parent star bright and shining, is expected to issue a much higher proportion of high-energy photons from X-ray - with each of these warming potential ionizing photons and multiple atoms in its path, while a photon of a bright star just might reionize one or two atoms at most.
source of information:
http://www.universetoday.com/83239/astronomy-without-a-telescope-black-holes-the-early-years/
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