Reionization was the last major phase transition for most of the normal matter in the universe, and a landmark event in the early phases of galaxy formation. Lyman alpha emission from galaxies provides a good tool for probing reionization, because Lyman alpha is strongly scattered in a neutral intergalactic medium. We have applied this tool at redshift z=6.5, showing that the IGM is largely ionized by then. We are now working on higher redshift applications, with data in hand from a z=7.7 Lyman alpha search, and plans for z=8.8 searches afoot. We are also working to characterize the Lyman alpha selected population physically. I will show the first near-infrared spectra of such galaxies, which we are using to study rest-optical wavelength emission lines of low mass galaxies at redshift z=3. The combination of [OIII] and Lyman alpha lines provides evidence for galactic winds, which provides further evidence of active ongoing star formation, while establishing a key input parameter for modeling Lyman alpha galaxy populations in a neutral IGM.
April 9, 2010
11:00 am
Array Operations Center Auditorium
All NRAO employees are invited to attend via video, available in Charlottesville Room 230, Green Bank Room 137 and Tucson N525.
Local Host: Steve Myers