A study of 90 GHz dust emissivity on molecular cloud and filament scales
  Recent observations from the MUSTANG2 instrument on the Green Bank Telescope
have revealed evidence of enhanced long-wavelength emission in the dust
spectral energy distribution (SED) in the Orion Molecular Cloud (OMC) 2/3
filament on 25" ($\sim$0.1 pc) scales. Here we present a measurement of the
dust SED on larger spatial scales (map size 0.5-3 degrees or roughly 3-20pc),
at somewhat lower resolution (120", corresponding to 0.25 pc at the distance of
400pc) using data from the Herschel satellite and Atacama Cosmology Telescope
(ACT). We then extend these 120"-scale investigations to other regions covered
in the Herschel Gould Belt Survey (HGBS) specifically: the dense filaments in
the southerly regions of Orion A and its tail; Orion B; and Serpens-S. Our
dataset in aggregate covers approximately 10 deg$^2$, with continuum photometry
spanning from 160 um to 3mm. These data also show an excess of emission at 3mm,
though somewhat weaker (8.5% excess) compared to what is seen at higher
resolution. More strikingly, we find that the enhancement is present even more
strongly in the other filaments we targeted, with an average enhancement of
24.9% compared to a standard MBB fit to lambda $\leq$2mm data. By applying this
analysis to the other targeted regions we lay the groundwork for future
high-resolution observations and analysis. Finally, we also consider a
two-component dust model motivated by Planck results and an amorphous grain
dust model. While both of these have been proposed to explain deviations in
emission from a generic modified blackbody, we find that they do not perform
significantly better than a MBB spectrum for fitting the SEDs.
