Star Formation and Metallicity in High EQW(Ha) Galaxies A Search for Metal-Poor Candidates

Date of Award

2006

Document Type

Thesis

Degree Name

Bachelors

Department

Natural Sciences

First Advisor

Ruppeiner, George

Keywords

Star Formation, Galaxies, Galaxy Evaluation, High Resolution Optical Spectroscopy, Oxygen Abundance

Area of Concentration

Physics

Abstract

We present an investigation into the chemical abundances and star formation properties of the central regions in 187 Updated Zwicky Catalog (UZC) galaxies at cz > 5000 km/s. Spectra were obtained for the 187 galaxies with the Center for Astrophysics at Harvard University FAST spectrograph. Four galaxies were selected to have strong bursts of recent star formation and low dust content by constraining the sample to galaxies with EqW(Ha) < -70 and detectable 60 ?m IRAS fluxes. We calculate oxygen abundances for the entire sample using Kewley and Dopita�s (2000) metallicity and ionization parameter diagnostics using the [NII], [OII], [OIII], [SII], and the Balmer emission lines. Our results indicate extreme cases where these four intense star-forming systems were shown to have low chemical abundances, which suggests they are in the initial stages of galaxy evolution. Optical images of these galaxies and a few other members revealed irregular systems, many of which seemed to be interacting with nearby companions. Funding for this research was provided by the National Science Foundation Research Experience for Undergraduates program hosted by the Institute for Astronomy at University of Hawaii-Manoa, New College Foundation, New College Alumanae Association, and New College Division of Natural Sciences.

Rights

This bibliographic record is available under the Creative Commons CC0 public domain dedication. The New College of Florida, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.

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