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How will the James Webb Space Telescope measure First Light, Reionization, and Galaxy Assembly: The New Frontier after Hubble
TYPEAstrophysics Seminar
Speaker:Rogier A. Windhorst
Affiliation:Arizona State University
Date:21.05.2015
Time:11:30
Location:Lidow 605
Abstract:I will review how the 6.5 meter James Webb Space Telescope (JWST) --- after its
launch in 2018 --- can measure the epochs of First Light, Reionization, Galaxy
Assembly, and Supermassive Black-Hole Growth, building on recent results from the
Hubble Wide Field Camera 3.

First, I'll briefly summarize the significant technical progress on the design
and fabrication of JWST: more than 98% of its launch mass has been built, passed
final design, or is being built as of spring 2015. All JWST's 18 flight mirrors
have been gold-coated with an optical performance that meets or exceed specs. All
of JWST's scientific instruments were delivered to NASA GSFC and tested from mid
2013--2015. I will briefly summarize the path from today till launch, planned
with an Ariane V for October 2018.

Next, I will briefly review the search for the first galaxies at redshifts z=9-11
(age ~0.5 Gyr) in the Hubble UltraDeep and Frontier Fields, and their current
limitations. I will show what combination of area, depth, and wavelength coverage
are needed for JWST to detect a sufficient number of First Light objects, and to
measure their evolving luminosity function (LF). JWST will map the epoch of First
Light through the so-called Population III-star dominated objects at redshifts
z~8--15, and its transition to the first Pop II stars in dwarf galaxies at z~<9.
JWST will measure the evolution of the Schechter LF at z~6--15, when the Universe
was 0.3--1 billion years old. A steep faint-end of the dwarf galaxy LF may have
provided the ultraviolet flux needed to start and finish cosmic reionization.
JWST will also image the host galaxies of the first quasars at z>6 in detail.

I will argue that gravitational lensing by the most highly-concentrated rich
foreground galaxy clusters will need to be used to maximize the number of First
Light objects (z~>12-15) detected with JWST. Last, I will address how many random
Webb Deep Fields (WDFs) may need to be observed with JWST to see First Light,
compared to the best lensing targets.

http://www.jwst.nasa.gov/ or http://www.asu.edu/clas/hst/www/jwst/