לוח שנה משולב

From detecting food to locating lurking predators, visual search -- the ability to find an object of interest against a background -- needs to be accurate and fast to ensure survival. In mammals, this led to the development of a parallel search mode, pop-out, which enables fast detection time that is not dependent on the number of distracting objects. Although it may be beneficial to most animals, pop-out behavior has been observed only in mammals, where its neural correlates are found as early as V1 in contextually modulated cells that encode aspects of saliency. I will describe our recent findings of pop-out visual search in the archer fish and discuss possible implications about universality of visual search among vertebrates.

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~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/