Time :  2021/04/22 (Thu.) 12:30
Place : R521, 5F, 2nd General Building, Nat'l Tsing Hua Univ.

Abstract: 
I will give a high-level overview of the design, mission and status of
the Dark Energy Spectroscopic Instrument. DESI is an ambitious
astronomical survey project using a new instrument installed on the
4-m Mayall telescope in Arizona, funded by the US Department of Energy
and involving more than 500 researchers at 80 institutions worldwide
(including my group at NTHU). DESI will measure the effect of dark
energy on the expansion of the Universe by observing 40 million
distant galaxies over the next 5 years. We will also observe stars in
the Milky Way to better understand how our galaxy was assembled in the
distant past and measure its dark matter content. The main DESI survey
will begin in July, having spent the past 6 months in an intensive
testing program following almost 10 years of planning and
construction. I will try to explain why astronomers are excited about
DESI and the scientific questions it will help to answer, in
particular those concerning the formation of the Milky Way.