NOAO > Observing Info > Approved Programs > 2012A-0127
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NOAO > Observing Info > Approved Programs > 2012A-0127 |
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PI: Bethan James, Space Telescope Science Institute, bjames@stsci.edu
Address: 3700 San Martin Drive, Baltimore, MD 21218, USA
CoI: Mike Barlow, University College London
CoI: Alessandra Aloisi, Space Telescope Science Institute
CoI: Mark Westmoquette, European Southern Observatory, Garching
CoI: Tracy Beck, Space Telescope Science Institute
CoI: Oskar Karczewski, University College London
Title: The True Abundances of Star-Forming Galaxies: Ionized Gas with GMOS-IFU vs Neutral Gas with HST-COS
Abstract:
Galaxy metallicity and its evolution with redshift is of paramount importance
for understanding galaxy formation. ISM abundances are typically determined
from HII regions that may not be typical for the whole galaxy. This is
especially true for star-forming galaxies (SFGs), where the ionized-gas is
more rapidly affected by chemical evolution than the more abundant
neutral-gas. Quantifying the metals in both the neutral- and ionized-gas is
thus important to assess how reliably HII regions trace abundances of a
galaxy at any redshift. Our team has obtained HST/COS spectroscopy of the
neutral-gas along the sight lines of bright UV sources in 9 nearby SFGs. Here
we propose to obtain GMOS-IFU spectroscopy of 7 of these SFGs to complement
our COS observations. These new GMOS-N data will allow us to spatially
resolve the distribution of emission-line ratios, extinction, Te, Ne and
abundances along the same sight lines of the HII regions targeted by COS. Our
COS/GMOS project will be the first detailed and spatially-accurate comparison
between neutral- and ionized-gas abundances in local SFGs. The results will
provide new insights into the metallicity range within galaxies, with
possible implications for our understanding of the observed offset between
LBGs and DLA systems at higher redshift.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2012A-0127 |
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