A study of 90 GHz dust emissivity on molecular cloud and filament scales
Abstract
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" (0.1 pc) scales. Here we present a measurement of the SED on larger spatial scales (map size 0.5-3 degrees or 3-20 pc), at somewhat lower resolution (120", corresponding to 0.25 pc at 400 pc) using data from the Herschel satellite and Atacama Cosmology Telescope (ACT). We then extend the 120"-scale investigation to other regions covered in the Herschel Gould Belt Survey (HGBS) specifically: the dense filaments in the southerly regions of Orion A; Orion B; and Serpens-S. Our dataset in aggregate covers approximately 10 square degrees, with continuum photometry spanning from 160um to 3mm. These OMC 2/3 data display excess emission at 3mm, though less (10.9% excess) than what is seen at higher resolution. Strikingly, we find that the enhancement is present even more strongly in the other filaments we targeted, with an average excess of 42.4% and 30/46 slices showing an inconsistency with the modified blackbody to at least 4{\sigma}. Applying this analysis to the other targeted regions, we lay the groundwork for future high-resolution analyses. Additionally, 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 (MBB), we find that they have significant drawbacks, requiring many spectral points or lacking experimental data coverage.
Keywords
Cite
@article{arxiv.2105.13432,
title = {A study of 90 GHz dust emissivity on molecular cloud and filament scales},
author = {Ian Lowe and Brian Mason and Tanay Bhandarkar and S. E. Clark and Mark Devlin and Simon R. Dicker and Shannon M. Duff and Rachel Friesen and Alvaro Hacar and Brandon Hensley and Tony Mroczkowski and Sigurd Naess and Charles Romero and Sarah Sadavoy and Maria Salatino and Craig Sarazin and John Orlowski-Scherer and Alessandro Schillaci and Jonathan Sievers and Thomas Stanke and Amelia Stutz and Zhilei Xu},
journal= {arXiv preprint arXiv:2105.13432},
year = {2022}
}