On Sun, Jan 14, 2018 at 5:17 AM, <agrayson2...@gmail.com> wrote: > > I recently viewed a documentary on Quasars. IIRC, they are interpreted as > immense BH's with inflowing matter of galactic size to account for their > brightness, and their redshift, applying Hubble's Law, indicates they are > far removed, closer to the BB than any galaxies within our observable > universe. Question: did galaxies form that early after the BB to account > for the huge inflows of matter and brightness? TIA, AG >
Quasars formed very soon after the Big bang, almost embarrassedly soon. A recently discovered quasar called J1342+0928 is 13.1 billion light years away and was formed just 690 million years after the Big Bang, and yet it is powered by a Black Hole of 800 million solar masses. Astronomers have trouble explaining how a Black Hole could get that big that fast by conventional stellar evolution, but if from day one the universe already contained 100 solar mass Black Holes that would help a lot in explaining how that could happen and maybe give us a hint at what Dark Matter is too. We know from the percentage of the elements Hydrogen, Deuterium, Helium and Lithium in existence how much regular matter was around one minute after the Big Bang when nucleosynthesis cooked up these elements, and there is no room for Dark Matter. So the Black Holes that form the bulk of the Dark Matter can't have come from the corpses of dead stars made of regular matter; but maybe Black Holes formed long before nucleosynthesis occurred when the universe was much less than one minute old and things were too hot for even protons to exist much less elements. Stephen Hawking proposed this explanation for Dark Matter some years ago but the idea had fallen out of favor because it was largely (but not entirely) ruled out by the data. We know that to account for all the Dark Matter the Black Holes can't be larger than 100 solar masses because there would be more gravitational microlensing than we observe. And we know that to account for all the Dark Matter the Black Holes can't be smaller than 10 solar masses because we'd see Black Hole explosions / evaporations (if they were REALLY small) and the orbits of widely spaced binary stars would be disrupted, but we don't see any of that. But there is still a window for Primordial Black Holes being Dark Matter that the data hasn't excluded and it's between 10 and 100 solar masses, and that's just what LIGO discovered. LIGO has so far detected 6 collisions between Black Holes ranging in size between 36 and 7 solar masses resulting in Black Holes of 18, 21, 35, 49, 53, and 62 solar masses. So maybe 85% of all the matter in the universe is in the form of Primordial Black Holes. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
