PI: James Rhoads, Arizona State U., James.Rhoads@asu.edu
Address: School of Earth and Space Exploration, PO Box 871404, Tempe, AZ 85287-1404 USA
CoI: Sangeeta Malhotra, Arizona State U.
CoI: Ron G Probst, NOAO
CoI: Rob Swaters, NOAO
CoI: Pascale Hibon, Gemini Observatory South
CoI: Bahram Mobasher, UC Riverside
CoI: Vithal Tilvi, Texas A&M U.
CoI: Sylvain Veilleux, U. of Maryland
CoI: Junxian Wang, University of Science & Technology of China
CoI: Steven Finkelstein, U. of Texas, Austin
CoI: Zhenya Zheng, Arizona State U.
CoI: Alicia Gonzalez, Arizona State U.
CoI: Johannes Zabl, University of Copenhagen
CoI: Jacob Trahan, Arizona State U.
CoI: Kimberley Emig, Arizona State U.
CoI: Tianxing Jiang, Arizona State U.
CoI: Huan Yang, Arizona State U.
CoI: John Pharo, Arizona State U.
CoI: Bhavin Joshi, Arizona State U.
CoI: Mark Smith, Arizona State U.
Title: The Cosmic Deep And Wide Narrowband (Cosmic DAWN) Survey
Abstract: We propose a definitive test for the neutral gas fraction near the epoch of reionization using a survey of Lyman-alpha emitters at z=7.7. The redshift of reionization, its speed, and its homogeneity are unknowns, with the Gunn-Peterson tests probing the end of reionization at $z > 6$, while WMAP suggests $z_=11$. Ly-alpha galaxies provide a powerful tool to probe the central phase of reionization with neutral fractions of gas $\approx 50\%$ because the Lyman-alpha photons scatter resonantly. The observed Lyman-alpha luminosity function (LF) should then show a substantial decline. We pioneered the use of Ly-alpha emitters to show that the IGM is more than 50\% ionized at z = 6.5 (Malhotra \& Rhoads 2004). We now propose 40 nights of deep narrowband imaging in 4 fields to find \lya\ line emitters. The custom filter is designed, tested, and performing well in NEWFIRM. This survey is 40 times more powerful than the state of the art in this field. We expect to find 40 Lyman-alpha emitters, and 10 in each field, if the IGM is ionized at z=7.7. With four fields, we guard against cosmic variance and inhomogenieties in reionization. Even if the IGM at z=7.7 is 50\% neutral we will find 5 sources, which lie in an OH free wavelength and are good for spectroscopic followup. Presently, there are 0 confirmed Lyman-alpha emitters at $z > 7.3$.
Program Type: Survey
Run 1 (2013B): KP-4m/NEWFIRM -- 11n on Oct 31 - Nov 04 2013, Dec 05 - Dec 11 2013
Run 1 (2014A): KP-4m/NEWFIRM -- 11n on Mar 05 - Mar 09 2014, Mar 21 - Mar 26 2014
Run 1 (2014B): KP-4m/NEWFIRM -- 9n on Oct 17 - Oct 20 2014, Nov 21 - Nov 25 2014
Run 1 (2015A): KP-4m/NEWFIRM -- 12.5n on Mar 09 - Mar 12 2015, Mar 23 - Mar 26 2015, Apr 08 - Apr 12 2015
Run 1 (2015B): KP-4m/NEWFIRM -- 12.5n on Oct 15 - Oct 19 2015, Nov 06 - Nov 09 2015, Dec 07 - Dec 10 2015
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360