IPMU Colloquium (ACP)

Speaker: Andrew Bunker (University of Oxford)
Title: The First billion years of History - Star-forming galaxies at the end of the dark ages
Date (JST): Wed, Apr 10, 2013, 15:30 - 17:00
Place: Lecture Hall
Related File: 913.pdf
Abstract: The epoch about 1 billion years after the Big Bang is when the Universe undergoes a key phase transition - the mostly-neutral gas between the galaxies becomes plasma. I will discuss the role that star formation in galaxies might play in this reionization, and discuss the history of star formation in the Universe.
I will describe techniques to find galaxies at very high redshifts (within one billion years of the Big Bang), using Hubble Space Telescope imaging. By using selection based on images with many different filters, we can identify the rare furthest galaxies seen when the Universe was less than 10 per cent of its current age. The rest-frame UV light from these galaxies can be used to estimate the star formation rate.
I will present follow-up spectroscopy from the ground (including from Subaru), with which we have confirmed the high redshift nature of this population. Additionally, using infrared imaging with Spitzer, we can estimate the ages of the stars in these early galaxies, and the total number of stars which have already formed.
I will also outline potential future work with the James Webb Space Telescope and Extremely Large Telescopes.
Seminar Video: [VIDEO]