Abstract
The Wyoming Survey for Hα, or WySH, is a large-area, ground-based, narrowband imaging survey for Hα-emitting galaxies over the latter half of the age of the universe. The survey spans several square degrees in a set of fields of low Galactic cirrus emission. The observing program focuses on multiple Δz 0.02 epochs from z 0.16 to z 0.81 down to a uniform (continuum+line) luminosity at each epoch of 1033 W uncorrected for extinction (3σ for a 3″ diameter aperture). First results are presented here for 98+208 galaxies observed over approximately 2 deg2 at redshifts z 0.16 and 0.24, including preliminary luminosity functions at these two epochs. These data clearly show an evolution with lookback time in the volume-averaged cosmic star-formation rate. Integrals of Schechter fits to the extinction-corrected Hα luminosity functions indicate star-formation rates per co-moving volume of 0.009 and 0.014 h 70 M ⊙ yr-1 Mpc-3 at z 0.16 and 0.24, respectively. The formal uncertainties in the Schechter fits, based on this initial subset of the survey, correspond to uncertainties in the cosmic star formation rate density at the ≳40% level; the tentative uncertainty due to cosmic variance is 25%, estimated from separately carrying out the analysis on data from the first two fields with substantial datasets.
Original language | English (US) |
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Pages (from-to) | 1412-1420 |
Number of pages | 9 |
Journal | Astronomical Journal |
Volume | 135 |
Issue number | 4 |
DOIs | |
State | Published - Apr 1 2008 |
Funding
Keywords
- Galaxies: evolution
- Galaxies: luminosity function, mass function
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science