Shocks and Metallicity Gradients in Normal Star-Forming Galaxies

dc.contributor.author Ho, I-Ting
dc.date.accessioned 2017-12-18T22:09:58Z
dc.date.available 2017-12-18T22:09:58Z
dc.date.issued 2016-08
dc.description Ph.D. University of Hawaii at Manoa 2016.
dc.description Includes bibliographical references.
dc.description.abstract Gas flow is one of the most fundamental processes driving galaxy evolution. This thesis explores gas flows in local galaxies by studying metallicity gradients and galactic- scale outflows in normal star-forming galaxies. This is made possible by new integral field spectroscopy data that provide simultaneously spatial and spectral information of galaxies. First, I measure metallicity gradients in isolated disk galaxies and show that their metallicity gradients are remarkably simple and universal. When the metallicity gradients are normalized to galaxy sizes, all the 49 galaxies studied have virtually the same metallicity gradient. I model the common metallicity gradient using a simple chemical evolution model to understand its origin. The common metallicity gradient is a direct result of the coevolution of gas and stellar disk while galactic disks build up their masses from inside-out. Tight constraints on the mass outflow rates and inflow rates can be placed by the chemical evolution model. Second, I investigate galactic winds in normal star-forming galaxies using data from an integral field spectroscopy survey. I demonstrate how to search for galactic winds by probing emission line ratios, shocks, and gas kinematics. Galactic winds are found to be common even in normal star-forming galaxies that were not expected to host winds. By comparing galaxies with and without hosting winds, I show that galaxies with high star formation rate surface densities and bursty star formation histories are more likely to drive large-scale galactic winds. Finally, lzifu, a toolkit for fitting multiple emission lines simultaneously in integral field spectroscopy data, is developed in this thesis. I describe in detail the structure of the toolkit and demonstrate the capabilities of lzifu.
dc.identifier.uri http://hdl.handle.net/10125/51490
dc.language.iso eng
dc.publisher [Honolulu] : [University of Hawaii at Manoa], [August 2016]
dc.relation Theses for the degree of Doctor of Philosophy (University of Hawaii at Manoa). Physics & Astronomy
dc.title Shocks and Metallicity Gradients in Normal Star-Forming Galaxies
dc.type Thesis
dc.type.dcmi Text
Files
Original bundle
Now showing 1 - 2 of 2
No Thumbnail Available
Name:
2016-08-phd-ho_r.pdf
Size:
18.39 MB
Format:
Adobe Portable Document Format
Description:
Version for non-UH users. Copying/Printing is not permitted
No Thumbnail Available
Name:
2016-08-phd-ho_uh.pdf
Size:
18.11 MB
Format:
Adobe Portable Document Format
Description:
For UH users only