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Home List of Titles The WHIQII survey: metallicities and spectroscopic properties of luminous compact blue galaxies
Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/95254
- The WHIQII survey: metallicities and spectroscopic properties of luminous compact blue galaxies
- Tollerud, E. J.; Barton, E. J.; Van Zee, L.; Cooke, J.
- As part of the WIYN High Image Quality Indiana-Irvine (WHIQII) survey, we present 123 spectra of faint emission-line galaxies, selected to focus on intermediate redshift (0.4 lsim z lsim 0.8) galaxies with blue colors that appear physically compact on the sky. The sample includes 15 true Luminous Compact Blue Galaxies (LCBGs) and an additional 27 slightly less extreme emission-line systems. These galaxies represent a highly evolving class that may play an important role in the decline of star formation since z ~ 1, but their exact nature and evolutionary pathways remain a mystery. Here, we use emission lines to determine metallicities and ionization parameters, constraining their intrinsic properties and state of star formation. Some LCBG metallicities are consistent with a "bursting dwarf" scenario, while a substantial fraction of others are not, further confirming that LCBGs are a highly heterogeneous population but are broadly consistent with the intermediate redshift field. In agreement with previous studies, we observe overall evolution in the luminosity-metallicity relation at intermediate redshift. Our sample, and particularly the LCBGs, occupies a region in the empirical R 23-O 32 plane that differs from luminous local galaxies and is more consistent with dwarf irregulars at the present epoch, suggesting that cosmic "downsizing" is observable in even the most fundamental parameters that describe star formation. These properties for our sample are also generally consistent with lying between local galaxies and those at high redshift, as expected by this scenario. Surprisingly, our sample exhibits no detectable correlation between compactness and metallicity, strongly suggesting that at these epochs of rapid star formation, the morphology of compact star-forming galaxies is largely transient.
- Publication type
- Journal article
- Astrophysical Journal, Vol. 708, no. 2 (2010), pp. 1076-1091
- Publication year
- FOR Code(s)
- 0201 Astronomical and Space Sciences
- Galaxy evolution; High redshift galaxies; Starburst galaxies
- Institute of Physics Publishing
- Publisher URL
- Copyright © 2010 The American Astronomical Society. All rights reserved. The American Astronomical Society does not allow institutions to archive either the accepted manuscript or the published version of the article. However, you can find an earlier version of the full text here: http://arxiv.org/abs/0911.1789.
- Peer reviewed