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Deconstructing the WISE nearby galaxy population

This thesis aims to test the reliability of the Wide-Field Infrared Space Explorer (WISE) star formation indicators centred at 12 and 22 µm. To accomplish this, the total infrared (TIR) luminosity was used as a calibrator to understand the behaviour of the two indicators. Our sample consists of Spit...

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Main Author: August, Tamlyn
Other Authors: Jarrett, Thomas
Format: Thesis
Language:English
Published: Department of Astronomy 2020
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access_status_str Open Access
author August, Tamlyn
author2 Jarrett, Thomas
author_browse August, Tamlyn
Jarrett, Thomas
author_facet Jarrett, Thomas
August, Tamlyn
author_sort August, Tamlyn
collection Thesis
description This thesis aims to test the reliability of the Wide-Field Infrared Space Explorer (WISE) star formation indicators centred at 12 and 22 µm. To accomplish this, the total infrared (TIR) luminosity was used as a calibrator to understand the behaviour of the two indicators. Our sample consists of Spitzer galaxies from the SINGS and KINGFISH surveys, with a select few excluded. The TIR calibration also necessitates that most of our galaxies have FIR data from Herschel. The photometric analysis done on the raw WISE and Spitzer images of our galaxies is explained, including how the isophotes and background sky level were determined for each band/image. Once the reliability of the WISE indicators was established, new star formation rate relations were formulated. The new relations are comparable to previous relations in the literature, but improve on them in stellar mass-, metallicity-, and luminosity range. We also find that metallicity of the galaxies has minimal effect on our relations. In our comparison of emission from PAH molecules, the two bands in question, IRAC4 and W 3 are strongly correlated. This may suggest that the W3 band is dominated by emission from the 11.3 µm PAH molecule, or it might be an effect of the band overlap between IRAC4 and W3.
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institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:32:27.580Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2020
publishDateRange 2020
publishDateSort 2020
publisher Department of Astronomy
publisherStr Department of Astronomy
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source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/31149 Deconstructing the WISE nearby galaxy population August, Tamlyn Jarrett, Thomas Cluver, Michelle astronomy This thesis aims to test the reliability of the Wide-Field Infrared Space Explorer (WISE) star formation indicators centred at 12 and 22 µm. To accomplish this, the total infrared (TIR) luminosity was used as a calibrator to understand the behaviour of the two indicators. Our sample consists of Spitzer galaxies from the SINGS and KINGFISH surveys, with a select few excluded. The TIR calibration also necessitates that most of our galaxies have FIR data from Herschel. The photometric analysis done on the raw WISE and Spitzer images of our galaxies is explained, including how the isophotes and background sky level were determined for each band/image. Once the reliability of the WISE indicators was established, new star formation rate relations were formulated. The new relations are comparable to previous relations in the literature, but improve on them in stellar mass-, metallicity-, and luminosity range. We also find that metallicity of the galaxies has minimal effect on our relations. In our comparison of emission from PAH molecules, the two bands in question, IRAC4 and W 3 are strongly correlated. This may suggest that the W3 band is dominated by emission from the 11.3 µm PAH molecule, or it might be an effect of the band overlap between IRAC4 and W3. 2020-02-18T08:53:22Z 2020-02-18T08:53:22Z 2019 2020-02-18T08:04:29Z Master Thesis Masters MSc http://hdl.handle.net/11427/31149 eng application/pdf Department of Astronomy Faculty of Science
spellingShingle astronomy
August, Tamlyn
Deconstructing the WISE nearby galaxy population
thesis_degree_str Master's
title Deconstructing the WISE nearby galaxy population
title_full Deconstructing the WISE nearby galaxy population
title_fullStr Deconstructing the WISE nearby galaxy population
title_full_unstemmed Deconstructing the WISE nearby galaxy population
title_short Deconstructing the WISE nearby galaxy population
title_sort deconstructing the wise nearby galaxy population
topic astronomy
url http://hdl.handle.net/11427/31149
work_keys_str_mv AT augusttamlyn deconstructingthewisenearbygalaxypopulation