Radiative feedback for supermassive star formation in a massive cloud
  with H2 molecules in an atomic-cooling halo
  Recent three-dimensional cosmological simulations of protogalaxy formation
have suggested that supermassive stars (SMSs) can form in gas clouds in which
H$_2$ cooling is suppressed by dynamical heating prior to the activation of
atomic cooling (Wise et al. 2019), but they stopped short of the following
growth of a central protostar. Here we examine whether accretion on the
protostellar core in this cloud is sufficiently rapid, in the face of the
radiation feedback, to produce a SMS. We perform one-dimensional
radiation-hydrodynamical simulations of the hot collapsing cloud with
non-equilibrium chemical reactions directly adopting the cloud properties from
Wise et al. (2019) as an initial condition. We find that the stellar
Lyman-Werner (LW) radiation from the SMS dissociates H$_2$ in the inner regions
of the gas flow, increasing gas temperature and thermal pressure, and
temporarily stopping the accretion. However, this negative feedback ceases when
the self-gravity and inward ram pressure force on larger scales push the gas
inward. The central protostar is unable to expand an HII region due to the high
density, and grows to a mass of $\gtrsim10^5\,{{\rm M}_\odot}$. Our results
suggests the successful formation of SMSs, and resulting massive
($\sim10^5\,{{\rm M}_\odot}$) remnant black holes in the clouds, but need to be
confirmed in two- or three-dimensional simulations.
