SIMBAD references

We consider the physical conditions under which supermassive black holes could have formed inside the first galaxies. Our smoothed particle hydrodynamics simulations indicate that metal-free galaxies with a virial temperature of ∼10⁴ K and suppressed H₂formation (due to an intergalactic UV background) tend to form a binary black hole system that contains a substantial fraction (≳10%) of the total baryonic mass of the host galaxy. Fragmentation into stars is suppressed without substantial H₂cooling. Our simulations follow the condensation of ∼5x10⁶ M_☉around the two centers of the binary down to a scale of ≲0.1 pc. Low-spin galaxies form a single black hole instead. These early black holes lead to quasar activity before the epoch of reionization. Primordial black hole binaries lead to gravitational radiation emission at redshifts z≳10 that would be detectable by Laser Interferometer Space Antenna.