Key points are not available for this paper at this time.
, as seen in the simulations, is stable against fragmentation irrespective of its metallicity. This is at variance with conventional direct collapse scenarios, which require the suppression of gas cooling in metal-free protogalaxies for gas collapse to take place. Such high accretion rates reflect the high free-fall velocities in massive halos appearing only at z < 10, and occur naturally as a result of the efficient angular momentum loss provided by the merger dynamics. We discuss the implications of our scenario on the observed population of high-z quasars and on its evolution to lower redshifts using a semi-analytical galaxy formation model. Finally, we consider the intriguing possibility that the secondary gas inflows in the unstable disks might drive gas to collapse into a supermassive black hole directly via the General Relativistic radial instability. Such dark collapse route could generate gravitational wave emission detectable via the future Laser Interferometer Space Antenna (LISA).
Mayer et al. (Mon,) studied this question.