Astronomy Tea Talk

  The first galaxies are the next frontier of extragalactic research.  How and when did they form, and how did they contribute to reionization?  Answers to these questions require both census taking and detailed studies of individual galaxies.  Gravitational lensing improves the discovery efficiency of high-redshift candidates bright enough for follow-up study.  The Cluster Lensing And Supernova survey with Hubble (CLASH) Multi-Cycle Treasury program revealed candidates as distant as MACS0647-JD at z ~ 10.8 (420 Myr) lensed to 26th magnitude AB.  I will present new preliminary results from the first epochs of two programs following up the z ~ 11 candidate.  Hubble WFC3/IR grism spectroscopy should help confirm the redshift, and deep Spitzer imaging is constraining the galaxy's age, stellar mass, and rest-frame UV slope (beta).  I will also discuss my recent MOSFIRE spectroscopy attempting to confirm two CLASH lensed z ~ 8 candidates.  Building on the successes of CLASH and the UDF, the Frontier Fields are yielding more high redshift candidates.  I will present predictions and early results from this program.  Finally, I will look ahead to Euclid and WFIRST which could yield many more promising targets for JWST if the missions overlap.