Ever since learning about their possibility, Primordial Black Holes (PBHs) have been a pet interest. Of course every time I post about them, there are the inevitable "he-haw, what a dopey idea" responses. But with the detection of GWs and such large black holes merging, more interest has been focused on the potential formation and existence of PBHs. There now seems to be a little less he-hawing then previously encountered. Perhaps some of it has retreated to the cosmic closet.
On studying the hypothetical nature of Pop. III stars that supposedly formed all the super massive BHs of the early universe, and the seeds of galaxy formation, I ran across an interesting article about PBHs. It described an alternate formation mechanism for BHs, very distinct from the "must-come-from-a-star" dogma. The process, as some of you are aware (and probably he-haw about), results in what are called "Direct Collapse Black Holes" (DCBHs). These form simply by sufficient masses of primordial hydrogen (mostly) to collapse to a BH without a stellar precursor. Of course none of these concepts rule out the formation of massive stars at the same time, which did/might undergo "standard" core-collapse.
Having zero expertise in this subject, it seemed like a prime area of study. Reports from the deepest observations reveal that the age of the earliest quasars indicate that large black holes formed much earlier than could have been made by the continuous accretion of smaller BH mergers. Due to their size and early age estimates, such objects could very well provide evidence to support PBHs that formed by a direct collapse mechanism.
A brief search for such objects turned up two that appear to be the most distant observed to date. And time-wise, they should not exist according to standard model(s) of the early universe. For instance, Quasar ULAS J1342+0928* has a mass estimated at 800 million SMs, and ca. 690 million years old. And it is not alone. Another quasar, ULAS J1120+0641** has an estimated mass of ca. 2 x 10E9 SMs***, and is ca. 770 million years old. Again, they are not supposed to be there at this early stage, or so I have read (and no retractions have been encountered).
This data on the earliest quasars could support the formation of PBHs by DCBH formation. Of course data on such objects is rather limited, probably since they are not supposed to be there, and it seems that a lot of people would rather ignore them than modify their absolute certainties about the nature of the BB and everything that came out of it. Perhaps their dogma insists on it.
One of the interesting concepts of PBHs is that they can form in almost any size, and might answer some questions about the nature of the observable universe. And they are a known object that exists in the universe (no exotic matter required). So it is with considerable interest that I find a story on these PBHs here on space.com that actually supports the concept. Do you suppose supporters of such notions will be burned at the stake?
It seems likely there are many more of these "early" quasars, they just haven't been found since the current instruments to detect them are limited, and many could be much younger, based simply on the size of the two noted above. It may simply boil down to a need for more sophisticated instruments. If they keep finding younger and younger quasars, it would seem there is a problem somewhere in some BB theories.
This is one biochemist's view on the issue, admittedly a tad outside his expertise. And do remember, that in all of science, one's concepts are only as good as the data. Any suggestions, one way or another, would be entertaining!
*
https://en.wikipedia.org/wiki/ULAS_J1342+0928
**
https://en.wikipedia.org/wiki/ULAS_J1120+0641
*** A luminous quasar at a redshift of z = 7.085 (Nature)
The intergalactic medium was not completely reionized until approximately a billion years after the Big Bang, as revealed by observations of quasars with redshifts of less than 6.5. It has been difficult to probe to higher redshifts, however, because quasars have historically been identified in...
ui.adsabs.harvard.edu
Did I just hear a he-haw?!