Supermassive black holes in the early Universe

• Main Authors: Melia, F., McClintock, T. M.
• Other Authors: The University of Arizona
• Language: en
• Published: The Royal Society 2015
• Online Access: http://hdl.handle.net/10150/614765; http://arizona.openrepository.com/arizona/handle/10150/614765

The recent discovery of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.3 has exacerbated the time compression problem implied by the appearance of supermassive black holes only $\sim 900$ Myr after the big bang, and only $\sim 500$ Myr beyond the formation of Pop II and III stars. Aside from heralding the onset of cosmic reionization, these first and second generation stars could have reasonably produced the $\sim 5-20\;M_\odot$ seeds that eventually grew into $z\sim 6-7$ quasars. But this process would have taken $\sim 900$ Myr, a timeline that appears to be at odds with the predictions of $\Lambda$CDM without an anomalously high accretion rate, or some exotic creation of $\sim 10^5\;M_\odot$ seeds. There is no evidence of either of these happening in the local universe. In this paper, we show that a much simpler, more elegant solution to the supermassive black hole anomaly is instead to view this process using the age-redshift relation predicted by the $R_{\rm h}=ct$ Universe, an FRW cosmology with zero active mass. In this context, cosmic reionization lasted from $t\sim 883$ Myr to $\sim 2$ Gyr ($6\lesssim z\lesssim 15$), so $\sim 5-20\;M_\odot$ black hole seeds formed shortly after reionization had begun, would have evolved into $\sim 10^{10}\; M_\odot$ quasars by $z\sim 6-7$ simply via the standard Eddington-limited accretion rate. The consistency of these observations with the age-redshift relationship predicted by $R_{\rm h}=ct$ supports the existence of dark energy; but not in the form of a cosmological constant.