http://arxiv.org/abs/2208.13178
Recent observations with JWST have identified several bright galaxy candidates at $z\gtrsim 10$, some of which appear unusually massive (up to $\sim 10^{11}\ \rm M_{\odot}$). Such early formation of massive galaxies is difficult to reconcile with standard $\Lambda\rm CDM$ predictions, demanding very high star formation efficiency (SFE), possibly even in excess of the cosmic baryon mass budget in collapsed structures. With an idealized analysis based on linear perturbation theory and the Press-Schechter formalism, we show that the observed massive galaxy candidates can be explained with lower SFE than required in $\Lambda\rm CDM$, if structure formation is accelerated by massive ($\gtrsim 10^{9}\ \rm M_{\odot}$) primordial black holes (PBHs) that enhance primordial density fluctuations. We identify the region of PBH parameter space, allowed by existing empirical constraints, that can produce the most massive galaxy candidates observed by JWST, and discuss the general signatures of PBH cosmologies in the JWST era.
B. Liu and V. Bromm
Tue, 30 Aug 22
5/76
Comments: 7 pages, 3 figures, submitted to ApJL, comments are welcome
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