I will give a brief overview of the current status of observational galaxy formation at z>2, focussing on the use of the hydrogen Lyman-alpha (Lya) emission line. At z>2, Lya is basically the only line available for spectroscopic confirmation of UV selected galaxies, but it has also been very efficient as a tool to detect high-redshift galaxies on its own. Because of its sensitivity to neutral hydrogen, Lya is also a promising tool to study the epoch of re-ionization. I will particularly highlight the need for wide surveys, including recent results which indicate that the most luminous Lya emitters are more common than previously thought, with implications for future surveys as Euclid. Because of their brightness, these sources can be studied in great detail, already before the next generation of telescopes, with interesting findings.
However, due to its complex radiative transfer, it is basically unknown what observed Lya emission actually traces. Understanding this is a key aim of our perfectly matched narrow-band survey at the INT, which directly measures Lya for > 500 Halpha selected z=2.23 galaxies, of which I will present the first results.brief overview of the current status of observational galaxy formation at z>2, highlighting its first successes and current limitations. Most importantly, detailed (spectroscopic) information is currently restricted to a highly biased sample.
2015 June 04, 15:00
Observatório Astronómico de Lisboa (Seminar room)
Tapada da Ajuda, 1349-018 Lisboa