Feedback-regulated supermassive black hole seed formation

The nature of the seeds of high-redshift supermassive black holes (SMBHs) is a key question in cosmology. Direct collapse black holes (DCBHs) that form in pristine, atomic-line cooling haloes, illuminated by a Lyman-Werner (LW) UV flux exceeding a critical threshold J crit represent an attractive possibility. We investigate when and where these conditions are met during cosmic evolution. For the LW intensity, J LW , we account for departures from the background value in close proximity to star-forming galaxies. For the pristine halo fraction, we account for both (i) supernova-driven outflows and (ii) the inherent pollution from progenitor haloes. We estimate the abundance of DCBH formation sites, n DCBH (z), and find that it increases with cosmic time from n DCBH (z = 20) 10 -12 -10 -7 cMpc -3 to n DCBH (z = 10) 10 -10 -10 -5 cMpc -3 . Our analysis shows the possible importance of galactic winds, which can suppress the predicted n DCBH by several orders of magnitude, and cause DCBH formation to preferentially occur around the UV-brightest (M UV -21 1) star-forming galaxies. Our analysis further highlights the dependence of these predictions on (i) the escape fraction of LW photons, (ii) J crit , and (iii) the galactic outflow prescription.