Chemical Abundances
Emission-Line Galaxies
Galaxy Formation and Evolution
Star-Formation Histories

Louis Evan Abramson
Marusa Bradac 
Gabriel Brammer 
Adriano Fontana 
Karl Glazebrook 
Alaina L. Henry 
Austin Hoag 
Kuang-Han Hunag 
Charlotte Mason 
Takahiro Morishita
Laura Pentericci 
Xin Wang 

We propose a carefully designed set of observations of the lensing cluster Abell 2744 to study intrinsically faint magnified galaxies from the epoch of reionization to redshift of 1, demonstrating and characterizing complementary spectroscopic modes with NIRSPEC and NIRISS. The observations are designed to address the questions:

1. When did reionization happen and what were the sources of reionizing photons?
2. How do baryons cycle in and out of galaxies?  

This dataset with deep spectroscopy on the cluster and deep multiband NIRCAM imaging in parallel will enable a wealth of investigations and will thus be of interest to a broad section of the astronomical community. The dataset will illustrate the power and challenges of:

1. Combining rest frame UV and optical NIRSPEC spectroscopy for galaxies at the epoch of reionization;
2. Obtaining spatially resolved emission line maps with NIRISS; and
3. Combining NIRISS and NIRSPEC spectroscopy.

NIRCam: Parallel imaging
NIRISS: Wide Field Slitless Spectroscopy
NIRSpec: Multi-object Spectroscopy

Building on our extensive experience with HST stlitless spectroscopy and imaging in clusters of galaxies as part of the GLASS, WISP, SURFSUP, and ASTRODEEP projects, we will provide to the community the science-enabling products described below:

1. Quantitative comparison of spatially resolved (NIRISS) and spectrally resolved (NIRSPEC) spectroscopy;
2. Object based interactive exploration tools for multi-instrument datasets;
3. Interface for easy forced extraction of slitless spectra based on coordinates;
4. UV-optical spectroscopic templates of high redshift galaxies; and
5. NIRCAM parallel catalogs and a list of 26 z>=9 dropouts for spectroscopic follow-up in Cycle 2.

We are planning 5 community briefings to be held at STSCI and at the AAS, over a period of two years.

https://glass.astro.ucla.edu/ers/index.html

http://glass.astro.ucla.edu/ers/