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[edit] Extending Deep H-alpha Galaxy Surveys to Higher Redshift

[edit] Survey Overview

Hα nebular emission is one of the most direct tracers of star formation. As such, a great deal of our current understanding of star formation in local galaxies is based on an established history of Hα observational studies. However, there is a dearth of analogous work in the intermediate redshift universe - a critical period in galaxy evolution where the overall star formation activity reaches its maximum - because the line is shifted out of the optical window past z~0.4. Thus, we have begun a campaign to extend deep Hα galaxy surveys to earlier cosmic times by taking advantage of the new capabilities offered by the NOAO Extremely Wide-Field Infrared Imager (NEWFIRM) at the KPNO 4m. Our strategy is to obtain (1%) narrowband imaging of key extragalactic fields in low-OH airglow windows at 1.19 and 2.09 μm (Hα @ z~0.8 and 2.2 respectively). Coupled with IMACS at the Baade 6.5m, which is well-matched for obtaining optical spectroscopy for emission-line galaxy candidates identified in the NEWFIRM narrowband imaging, the data from this survey will enable a wide range of investigations including:

  1. a search for extremely metal poor galaxies (Z< Zsun/12) which are potentially in their initial phases of star formation and/or have lost a significant amount of metals to the IGM via outflows,
  2. direct comparison of star formation rates (SFRs) derived from multiple tracers (e.g., Hα, [OII]3727, GALEX UV) over a broad mass and metallicity range,
  3. examination of dust extinction via Balmer line ratios,
  4. computation of Hα luminosity functions and SFR volume densities, and
  5. large-scale environmental studies of the most prodigiously star-forming systems.

[edit] Survey Members

Janice Lee (Carnegie Observatories)
Chun Ly (Space Telescope Science Institute)
Danny Dale (University of Wyoming)
Iva Momcheva (Carnegie Observatories)
Samir Salim (Indiana University)
Masami Ouchi (University of Tokyo)
Rose Finn (Siena College)


Student Collaborators

Kimihiko Nakajima (University of Tokyo)
Shawn Staudaher (University of Wyoming)
Jesse Feddersen (Indiana University)


Former Student Collaborators

Carolynn Moore (University of Wyoming)

[edit] Publications

Extending Deep H-alpha Galaxy Surveys to Higher Redshift with NEWFIRM. Lee, Janice C. et al., in preparation

The H-alpha Luminosity Function and Star-Formation Rate Volume Density at z=0.8 from the NEWFIRM H-alpha Survey

2011. Ly, C., Lee, J.C., Dale, D.A., Momcheva, I., Salim, S., Staudaher, S., Moore, C.A., Finn, R., ApJ, in press

Newfirm Hα Galaxy survey: Deep Follow-up Spectroscopy of z=0.8 Star Forming Galaxies

2010. Momcheva, I.G., Lee, J.C., Ly, C., Salim, S., Dale, D., Garcia, C., Finn, R., Ouchi, M. American Astronomical Society, 215, 36806

The Universe as Viewed from Star Forming Galaxies over the Past Ten Billion Years

2010. Ly, C., Malkan, M., Lee, J. C., Kashikawa, N., Hayashi, M., Motohara, K., Subaru Deep Field Collaboration, NEWFIRM Narrow-band H-alpha Survey team, 215, 33801 (PPT file)

Extending Deep H-alpha Galaxy Surveys to Higher Redshift with NEWFIRM.

2009. Lee, Janice C., Ly, C., Moore, C., Salim, S., Dale, D., Finn, R. & Momcheva, I. American Astronomical Society, 213, 42401. (PDF FILE)

H-alpha Luminosity Functions and Star Formation Rate Volume Densities at z=0.8.

2009. Ly, C., Lee, Janice C., Dale, D., Salim, S., Moore, C., Finn, R. & Momcheva, I. American Astronomical Society, 213, 42402. (PDF FILE)
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