Presentasjon av masteroppgave: Daniel Christopher Herman

Thermal Dust Emission in the Microwave Frequency Range

Abstract

Disentangling Galactic foreground emission from microwave frequency data sets is paramount to extracting the Cosmic Microwave Background (CMB) signal. With the community of cosmologists searching for the elusive B-mode CMB polarization signature, it
is vital that our collective ability to accurately model Galactic dust emission improves.
Understanding the physical nature of Galactic dust is also important to other fields
of astronomy, as dust emission can glean information about the composition of dust
grains, and the strength of the interstellar radiation field.

In this thesis, I aim to dissect Galactic thermal dust modeling through a host of analytical methods. A set of physical and phenomenological dust models are reviewed to set the stage for my analysis. The parametric methods which have been used to apply phenomenological dust models to data are also described. Calibration of the Planck and DIRBE data using COBE/FIRAS data, within the relevant frequency ranges, is carried out to ensure that estimates to our modeling parameters remain unbiased. The correlation between thermal dust and the hydrogen column density is fundamental in this research, and is applied through multiple analytical approaches.

The results of the analysis are presented to highlight issues with current thermal
dust modeling, particularly with published dust temperature maps. Constraints on the
number of parameters required to model thermal dust are set, and motivations for a
two-component dust model are laid out. Future work to improve upon this analysis and
implementation of a physical dust model to component separation are also described
here.

 

Veileder: Førsteamanuensis Ingunn Kathrine Wehus, Institutt for teoretisk astrofysikk, UiO

Medveileder: Professor Hans Kristian Kamfjord Eriksen, Institutt for teoretisk astrofysikk, UiO

Medveileder: Stipendiat Trygve Leithe Svalheim, Institutt for teoretisk astrofysikk, UiO

Medveileder: Postdoktor Brandon Hensley, Department of Astrophysical Sciences, Princeton University

Intern sensor: Professor David F. Mota, Institutt for teoretisk astrofysikk, UiO

Ekstern sensor: Postdoktor Mathieu Remazeilles, School of Physics and Astronomy, University of Manchester

Publisert 4. juni 2019 09:29 - Sist endret 6. juni 2019 08:16