The descendants of the first quasars in the BlueTides simulation


Abstract in English

Supermassive blackholes with masses of a billion solar masses or more are known to exist up to $z=7$. However, the present-day environments of the descendants of first quasars is not well understood and it is not known if they live in massive galaxy clusters or more isolated galaxies at $z=0$. We use a dark matter-only realization (BTMassTracer) of the BlueTides cosmological hydrodynamic simulation to study the halo properties of the descendants of the most massive black holes at $z=8$. We find that the descendants of the quasars with most massive black holes are not amongst the most massive halos. They reside in halos of with group-like ($sim 10^{14}M_{odot}$) masses, while the most massive halos in the simulations are rich clusters with masses $sim 10^{15} M_{odot}$. The distribution of halo masses at low redshift is similar to that of the descendants of least massive black holes, for a similar range of halo masses at $z=8$, which indicates that they are likely to exist in similar environments. By tracing back to the $z = 8$ progenitors of the most massive (cluster sized) halos at $z=0$; we find that their most likely black hole mass is less than $10^7 M_{odot}$; they are clearly not amongst the most massive black holes. We also provide estimates for the likelihood of finding a high redshift quasar hosting a black hole with masses above $10^{7} M_{odot}$ for a given halo mass at $z=0$. For halos above $10^{15} M_{odot}$, there is only $20 %$ probability that their $z=8$ progenitors hosted a black hole with mass above $10^{7} M_{odot}$.

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