Change search
ReferencesLink to record
Permanent link

Direct link
Far-infrared to Millimeter Interstellar Dust Models Ground Station Design for UWE-1
2007 (English)Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
Abstract [en]

I implemented a new description of astronomical dust emission in the spectral region from the Far-Infrared to millimeter wavelengths in a numerical model (by D¨¦sert et al. 1990) describing thermal fluctuations of small interstellar grains. Unlike previous numerical models, the improved model explicitly incorporates the effect of the disordered internal structure of amorphous dust grains, which takes into account the fact that dust material is amorphous in nature. The new model is inspired from the work of Meny et al. 2007 and takes into account the effect of absorption by Disordered Charge Distribution, as well as the effect of absorption by localized Two Level Systems. I greatly improved the calculations of the grain temperature fluctuations, especially for the low temperature case (down to 0.01 K), which was not well taken into account in the original model. An original contribution of this work is to have included TLS effect for thermally fluctuating dust particles. I also greatly improved the computing time of the code. Our calculation shows that the shape of the dust emission spectrum will exhibit very broad structures whose shape will change with the temperature of dust grains in a non trivial way. This could be helpful to explain the observed excess of millimeter emission. I believe that the improved dust Model more precise and will allow to identify the mechanical nature of astronomical dust from the observed shape of the FIR/mm emission spectrum. Predictions of this model indicate that TLS emission from Very Small Grains should be detectable in the FIR/Submm dust emission spectrum, in particular in regions such as Photo-Dissociation Regions, where the Interstellar Radiation Field is sufficiently high. This could make it possible to reveal the mechanical structure of the smallest dust grains by using the Herschel and Planck data. In the future, this model will be used to interpret the shape of the Spectral Energy Distribution of dust emission as measured by Planck and Herschel.

Place, publisher, year, edition, pages
Keyword [en]
Keyword [sv]
URN: urn:nbn:se:ltu:diva-51741ISRN: LTU-PB-EX--07/074--SELocal ID: 8ecdeac3-d776-441f-818b-7b547a0a74daOAI: diva2:1025105
Subject / course
Student thesis, at least 15 credits
Educational program
Space Engineering, master's level
Validerat; 20101217 (root)Available from: 2016-10-04 Created: 2016-10-04Bibliographically approved

Open Access in DiVA

fulltext(5045 kB)14 downloads
File information
File name FULLTEXT01.pdfFile size 5045 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search outside of DiVA

GoogleGoogle Scholar
Total: 14 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 1 hits
ReferencesLink to record
Permanent link

Direct link