The standard model of low-mass star formation applied to massive stars:
  a multi-wavelength picture of AFGL 2591
  This paper aims to investigate the hypothesis that the embedded luminous star
AFGL2591-VLA3 (2.3E5Lsun at 3.33kpc) is forming according to a scaled-up
version of a low-mass star formation scenario. We present multi-configuration
VLA 3.6cm and 7mm, as well as CARMA C18O and 3mm continuum observations to
investigate the morphology and kinematics of the ionized gas, dust, and
molecular gas around AFGL2591. We also compare our results to ancillary near-IR
images, and model the SED and 2MASS image profiles of AFGL2591 using a dust
continuum radiative transfer code. The observed 3.6cm images uncover for the
first time that the central powering source AFGL2591-VLA3 has a compact core
plus collimated jet morphology, extending 4000AU eastward from the central
source with an opening angle of <10deg at this radius. However, at 7mm VLA3
does not show a jet morphology, but instead compact (<500AU) emission, some of
which (<0.57 mJy of 2.9mJy) is estimated to be from dust. We determine that the
momentum rate of the jet is not sufficient to ionize itself via only shocks,
and thus a significant portion of the emission is instead likely created in a
photoionized wind. The C18O emission uncovers dense entrained material in the
outflow(s) from the young stars in the region. The main features of the SED and
2MASS images of AFGL2591-VLA3 are also reproduced by our model dust geometry of
a rotationally flattened envelope with and without a disk. The above results
are consistent with a picture of massive star formation similar to that seen
for low-mass protostars. However, within its envelope, AFGL2591-VLA3 contains
at least four other young stars, constituting a small cluster. Therefore it
appears that AFGL2591-VLA3 may be able to source its accreting material from a
shared gas reservoir while still exhibiting the phenomena expected during the
formation of low-mass stars. (Abridged)
