NOAO >   Observing Info >   Approved Programs >   2015A-0406

# Program Information for 2015A-0406

PI: Amy Barger, U. of Wisconsin, Madison, barger@astro.wisc.edu

CoI: Laura Trouille, Northwestern U.
CoI: Isak Wold, U. of Texas, Austin
CoI: Lennox L Cowie, U. of Hawaii
CoI: Esther Hu, U. of Hawaii

Title: Extreme Star-Forming Galaxies from z=0 to 2

Abstract: We propose to observe the population of galaxies with ultra-strong emission lines (USELs; rest-frame EW(H$\beta)>30$~\AA). USELs have extremely high specific star formation rates, are relatively common at $z=0.2-1$, and contain a significant fraction (about 5\%) of the universal star formation at these redshifts. The USEL population contains some of the lowest metallicity galaxies yet known and offers the potential for determining whether there is a metallicity floor on late forming galaxies, or whether there are regions where galaxies are still accreting extremely low metallicity gas from their surroundings. On Subaru we have begun a 200~deg$^2$ survey using a 9200~\AA\ filter with a width of 100~\AA\ to a $5\sigma$ limiting AB magnitude of 23.5 to provide a sample of about 20,000 USELs. We are currently obtaining the narrowband imaging with Suprime-Cam (SC) and the continuum observations with Hyper Suprime-Cam (HSC), since narrowband filters are not yet available for HSC. We have already covered 8~deg$^2$. We have 4 nights of SC imaging in Dec and 3 nights of HSC imaging in Jan to cover a further 8~deg$^2$. We have developed a procedure for picking out the lowest metallicity galaxies via color pre-screening, shallow spectroscopy with Hydra on WIYN, and deep spectroscopy with DEIMOS on Keck. We will use 5 WIYN nights allocated in Jan to follow up the first 8~deg$^2$. Here we request 5 more WIYN nights to follow up the second 8~deg$^2$ field.

Program Type: WTAC

Scheduled Nights:
Run 1 (2015A):  WIYN/HYDR -- 6n on Feb 13 - Feb 18 2015

National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360

 NOAO >   Observing Info >   Approved Programs >   2015A-0406