Far-Infrared Dust Temperatures and Column Densities of the MALT90
  Molecular Clump Sample
  We present dust column densities and dust temperatures for $\sim3000$ young
high-mass molecular clumps from the Millimetre Astronomy Legacy Team 90 GHz
(MALT90) survey, derived from adjusting single temperature dust emission models
to the far-infrared intensity maps measured between 160 and 870 \micron\ from
the Herschel/Hi-Gal and APEX/ATLASGAL surveys. We discuss the methodology
employed in analyzing the data, calculating physical parameters, and estimating
their uncertainties. The population average dust temperature of the clumps are:
$16.8\pm0.2$ K for the clumps that do not exhibit mid-infrared signatures of
star formation (Quiescent clumps), $18.6\pm0.2$ K for the clumps that display
mid-infrared signatures of ongoing star formation but have not yet developed an
HII region (Protostellar clumps), and $23.7\pm0.2$ and $28.1\pm0.3$ K for
clumps associated with HII and photo-dissociation regions, respectively. These
four groups exhibit large overlaps in their temperature distributions, with
dispersions ranging between 4 and 6 K. The median of the peak column densities
of the Protostellar clump population is $0.20\pm0.02$ gr cm$^{-2}$, which is
about 50% higher compared to the median of the peak column densities associated
with clumps in the other evolutionary stages. We compare the dust temperatures
and column densities measured toward the center of the clumps with the mean
values of each clump. We find that in the Quiescent clumps the dust temperature
increases toward the outer regions and that they are associated with the
shallowest column density profiles. In contrast, molecular clumps in the
Protostellar or HII region phase have dust temperature gradients more
consistent with internal heating and are associated with steeper column density
profiles compared with the Quiescent clumps.
