NOAO >   Observing Info >   Approved Programs >   2016B-0272

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Program Information for 2016B-0272


PI: Kyoung-Soo Lee, Purdue U., soolee@purdue.edu
Address: Physics Department, 525 Northwestern Avenue, West Lafayette, Indiana 47907 United States

CoI: Arjun Dey, NOAO
CoI: Rui Xue, Purdue U.
CoI: Ke Shi, Purdue U.
CoI: Naveen Reddy, UC Riverside
CoI: Hanae Inami, Observatoire de Lyon

Title: The Origin and Fate of Ly(alpha) Photons at High Redshift

Abstract: Ly$alpha$ emission line is a tracer of the ionizing photons produced by massive young stars. Redshifted Ly$alpha$ emission into the optical wavelengths offers a window into the high-redshift universe, where star formation activities in galaxies are on the rise. Even though our ability to identify and study high-redshift galaxies often critically rests on Ly$alpha$ line identification, and progressively more so for higher-redshift and lower-luminosity galaxies, it is poorly understood how Ly$alpha$ photons propagate through and eventually escape the galaxy. We propose to obtain deep narrow-band observations of a 1~deg$^2$ extragalactic field, with the primary goal of identifying a statistically significant sample of Ly$alpha$ emitting galaxies (LAEs) at $zsim3.78$. By using the proposed data in conjunction with existing deep supporting data in the field, we will elucidate dominant physical processes that control and facilitate the propagation and eventual escape of Ly$alpha$ photons in high-redshift galaxies. More specifically, first, we will make robust measurements of extended Ly$alpha$ emission around LAEs, namely their sizes and fractional contribution to the total integrated luminosity, and how they change with galaxy parameters such as UV luminosity and internal reddening by dust. Second, we will compare the relative attenuation of UV photons to Ly$alpha$ as a function of galaxy's morphology, stellar mass, and extinction parameters, thereby infer the relative geometry of dust and gas in these galaxies. Finally, we will make statistically robust determination of Ly$alpha$ luminosity function and equivalent widths distribution at $zsim 3.78$, filling the existing gap in the observed redshift evolution of LAEs.

Program Type: Standard/Extragalactic

Scheduled Nights:
Run 1 (2016B):  KP-4m/MOSA3 -- 6.5n on Dec 27 - Jan 02 2017


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 >   2016B-0272

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