Thesis
The spatial profile of tidally induced star formation
University of Iowa
Master of Science (MS), University of Iowa
Spring 2020
DOI: 10.17077/etd.005419
Abstract
We use the MaNGA integral field spectroscopic (IFS) survey to study star formation in interacting galaxies. We identify a set of galaxy pairs both inside and outside of the MaNGA survey's field of view. We build radial profiles of specific star formation rate (sSFR) for the MaNGA targets with spectroscopic pairs and compare their profiles against a set of isolated control galaxies. We study how these profiles are affected by the stellar mass of the galaxy, the mass ratio between the galaxies, and the projected separations between the galaxies. We find that galaxy pairs tend to have centrally enhanced sSFR of about 0.25 $\pm$ 0.1 dex in their centers. This level of enhancement is found to be unaffected by the stellar mass of the galaxy, is strongest in galaxy pairs with 1:1 mass ratios, and is also strongest at projected separations of 5$-$10 kpc. Galaxy pairs with projected separations below 5 kpc are found to have no enhancements to sSFR in comparison to control galaxies, which indicates a delay between the passage of the first pericenter and the arrival of the gas inflows to the centers of the galaxies. The centrally enhanced star formation rate causes the paired galaxies to experience an increased mass growth rate of $\sim$1.5$-$6.5\% in their centers, which is roughly 1.6$\times$ faster than secular evolution.
Details
- Title: Subtitle
- The spatial profile of tidally induced star formation
- Creators
- Joshua L Steffen
- Contributors
- Hai Fu (Advisor)Robert Mutel (Committee Member)Steven Spangler (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Physics
- Date degree season
- Spring 2020
- DOI
- 10.17077/etd.005419
- Publisher
- University of Iowa
- Number of pages
- vii, 75 pages
- Copyright
- Copyright 2020 Joshua L Steffen
- Language
- English
- Description illustrations
- color illustrations
- Description bibliographic
- Includes bibliographical references (pages 72-75).
- Public Abstract (ETD)
In this work we study how star formation in galaxies is affected by the interaction between galaxies. We use the MaNGA survey which allows us to study these galaxies with great spatial detail. We find that star formation is significantly enhanced in the centers of the merging galaxies when compared to isolated galaxies. On top of this, we find that this enhancement is unaffected by the mass of the galaxies, but is affected by the ratio between the masses of the galaxies. We also see that this enhancement in star formation can be seen to vary between the separation between the pairs where all but the closest pairs show the strongest levels of enhancement. In the closest pairs we see that the rate of star formation is identical to isolated galaxies. From this, we infer that there is a delay between the first close pass of the galaxies and onset of the enhanced star formation. The resulting mass growth from the merger induced star formation is roughly 1.6x the mass growth rate of isolated galaxies.
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9983966296102771
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