COMAP Galactic science I: observations of spinning dust emission at 30 GHz in dark clouds surrounding the λ-Orionis H ii region
Year: 2024
Type: article
Abstract: ABSTRACT Anomalous microwave emission (AME) is a major component of Galactic emission in the frequency band 10–60 GHz and is commonly modelled as rapidly rotating spinning dust grains. The photodissociation region (PDR) at the boundary of the $\lambda$-Orionis H ii region has been identified by several recent analyses as one of the brightest spinning dust-emitting sources in the sky. We investigate the Barnard 30 dark cloud, a dark cloud embedded within the $\lambda$-Orionis PDR. We use total-power observations of Barnard 30 from the CO Mapping Array Project (COMAP) pathfinder instrument at 26–34GHz with a resolution of 4.5 arcmin alongside existing data from Planck, WISE, IRAS, ACT, and the 1.447 GHz GALFACTS survey. We use aperture photometry and template fitting to measure the spectral energy distribution of Barnard 30. We find that the spinning dust is the dominant emission component in the 26–34GHz range at the $6\, \sigma$ level ($S_{30\, \mathrm{GHz}} = 3.35\pm 0.56$ Jy). From correlating COMAP data with dust templates we find no evidence that polycyclic aromatic hydrocarbons are the preferred carrier for the spinning dust emission, suggesting that the spinning dust carriers are due to a mixed population of very small grains. Finally, we find evidence for variations in spinning dust emissivity and peak frequency within Barnard 30, and that these variations are possibly driven by changes in dust grain population and the total radiation field. Confirming the origin of the variations in the spinning dust spectrum will require both future COMAP observations at 15 GHz combined with spectroscopic mid-infrared data of Barnard 30.
Authors: Stuart E Harper, Clive Dickinson, Kieran A Cleary, Brandon S Hensley, Gabriel A Hoerning, Roberta Paladini, Thomas J Rennie, R Cepeda-Arroita, Delaney A Dunne, Hans Kristian Eriksen, Joshua Ott Gundersen, Håvard T Ihle, Jonas G S Lunde, Roberto Ricci, Jeroen Stil, Nils-Ole Stutzer, A R Taylor, Ingunn Kathrine Wehus
Institutions: University of Manchester, California Institute of Technology, Jet Propulsion Laboratory, Infrared Processing and Analysis Center, University of British Columbia, University of Oslo, University of Miami, Istituto di Radioastronomia di Bologna, University of Calgary, University of Cape Town, Inter-university Institute for Data Intensive Astronomy, University of the Western Cape
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,012
Awards: Cosmoglobe -- mapping the universe from the Milky Way to the Big Bang, G356520432, Collaborative Research: The CO Mapping Array Pathfinder, G4822091501, Collaborative Research: The CO Mapping Array Pathfinder, Collaborative Research: The CO Mapping Array Pathfinder, G6144305072, Astrophysics and Cosmology Research within the JBCA 2017-2020, Collaborative Research: The CO Mapping Array Pathfinder, Line Intensity Mapping with the CO Mapping Array Pathfinder - Probing Two Key Epochs in Cosmic Evolution, The CO-Mapping Array Pathfinder Survey - A New Window on Cosmic Evolution, Time-domain Gibbs sampling: From bits to inflationary gravitational waves, G831849349
OpenAlex ID: W4405583118