Matching Items (3)
Filtering by

Clear all filters

135330-Thumbnail Image.png
ContributorsPowell, Devon (Author) / Gardner, Carl (Thesis director) / Scannapieco, Evan (Committee member) / Windhorst, Rogier (Committee member) / Barrett, The Honors College (Contributor)
Created2012-05
132911-Thumbnail Image.png
Description
I test the hypothesis that galactic magnetic fields originate from regions of dense
star formation (Dahlem et al. 2006) by comparing maps of 120-240 MHz synchrotron emission and hydrogen alpha (Hα) emission of the tidally-interacting, edge-on, barred spiral galaxy UGC 9665. Synchrotron emission traces magnetic field strength to a rough first

I test the hypothesis that galactic magnetic fields originate from regions of dense
star formation (Dahlem et al. 2006) by comparing maps of 120-240 MHz synchrotron emission and hydrogen alpha (Hα) emission of the tidally-interacting, edge-on, barred spiral galaxy UGC 9665. Synchrotron emission traces magnetic field strength to a rough first order, while Hα emission traces recent massive star formation. UGC 9665 was selected because it was included in the LOw Frequency ARray (LOFAR) TwoMetre Sky Survey (LoTSS; Shimwell et al. (2017)) as well as the Calar Alto Legacy Integral Field Area Survey (CALIFA; Sanchez et al. (2012)). I generated vertical intensity profiles at several distances along the disk from the galactic center for synchrotron emission and Hα in order to measure how the intensity of each falls off with distance from the midplane. In addition to correlating the vertical profiles to see if there is a relationship between star formation and magnetic field strength, I fit the LOFAR vertical profiles to characteristic Gaussian and exponential functions given by Dumke et al. (1995). Fitting these equations have been shown to be good indicators of the main mode of cosmic ray transport, whether it is advection (exponential fit) or diffusion (Gaussian fit) (Heesen et al. 2016). Cosmic rays originate from supernova,
and core collapse supernovae occur in star forming regions, which also produce
advective winds, so I test the correlation between star-forming regions and advective regions as predicted by the Heesen et al. (2016) method. Similar studies should be conducted on different galaxies in the future in order to further test these hypotheses and how well LOFAR and CALIFA complement each other, which will be made possible by the full release of the LOFAR Two-Metre Sky Survey (LoTSS) (Shimwell et al. 2017).
ContributorsHuckabee, Gabriela R (Author) / Jansen, Rolf (Thesis director) / Windhorst, Rogier (Committee member) / Bowman, Judd (Committee member) / School of Earth and Space Exploration (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
133462-Thumbnail Image.png
Description
Both strong and weak gravitational lensing allow astronomers to calculate the mass distribution of the foreground lens by analysis of the distortion of the lensed light. This process is currently the most precise way to quantify the presence of dark matter in galaxies. In addition, strong gravitational lensing allows astronomers

Both strong and weak gravitational lensing allow astronomers to calculate the mass distribution of the foreground lens by analysis of the distortion of the lensed light. This process is currently the most precise way to quantify the presence of dark matter in galaxies. In addition, strong gravitational lensing allows astronomers to observe directly the light from the background source, as it will be both magnified in brightness and easier to resolve. Current computer models can essentially "remove" the foreground galaxy/galaxies to isolate and reconstruct an image of the background source with a resolution greater than that observed without lensing. Both the measurement of dark matter within galaxies and the direct observation of lensed galaxies are goals for this project. This was done using LENSTOOL, a software package chosen for the project, and originally designed to perform such calculations efficiently. While neither goal was met in its entirety, this paper reflects the results of this project throughout the course of the past year.
ContributorsCompanik, Connor Matthew (Author) / Scowen, Paul (Thesis director) / Windhorst, Rogier (Committee member) / Jansen, Rolf (Committee member) / School of Earth and Space Exploration (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05