The massive protostar W43-MM1 as seen by Herschel-HIFI water spectra:
  high turbulence and accretion luminosity
  We present Herschel/HIFI observations of fourteen water lines in W43-MM1, a
massive protostellar object in the luminous star cluster-forming region W43. We
analyze the gas dynamics from the line profiles using Herschel-HIFI
observations (WISH-KP) of fourteen far-IR water lines (H2O, H217O, H218O),
CS(11-10), and C18O(9-8) lines, and using our modeling of the continuum
spectral energy distribution. As for lower mass protostellar objects, the
molecular line profiles are a mix of emission and absorption, and can be
decomposed into 'medium', and 'broad' velocity components. The broad component
is the outflow associated with protostars of all masses. Our modeling shows
that the remainder of the water profiles can be well fitted by an infalling and
passively heated envelope, with highly supersonic turbulence varying from 2.2
km/s in the inner region to 3.5 km/s in the outer envelope. Also, W43-MM1 has a
high accretion rate, between 4.0 x 10^{-4} and 4.0 x 10^{-2} \msun /yr, derived
from the fast (0.4-2.9 km/s) infall observed. We estimate a lower mass limit of
gaseous water of 0.11 \msun and total water luminosity of 1.5 \lsun (in the 14
lines presented here). The central hot core is detected with a water abundance
of 1.4 x 10^{-4} while the water abundance for the outer envelope is 8
x10^{-8}. The latter value is higher than in other sources, most likely related
to the high turbulence and the micro-shocks created by its dissipation.
Examining water lines of various energies, we find that the turbulent velocity
increases with the distance to the center. While not in clear disagreement with
the competitive accretion scenario, this behavior is predicted by the turbulent
core model. Moreover, the estimated accretion rate is high enough to overcome
the expected radiation pressure.
