The First Billion Years

August 16-20, 2010
California Institute of Technology - Pasadena, CA 91125

Final Report

Workshop Overview:

Of the nearly 14 billion year history of the Universe, we have probed only the last 13 billion years in any detail. In the missing first billion years of cosmic time are some of the most critical events in the history of the Universe, including the processes leading to the formation of the first star, the first galaxy, and the first black hole. This is the fundamental period when primordial density fluctuations following inflation evolved through baryon in-fall, adiabatic cooling, and gravitational collapse to create compact luminous structures for the first time. But probing this era is beyond the capabilities of today's instruments. New approaches are needed to enable break-through observations.

We propose a Study Program of technological and scientific exploration driven to study the first era of structure formation in the early Universe and to probe the interplay between dark matter and baryons at high redshift. The goal of our Study Program is to identify the most promising observational avenues to filling the missing history. It will lead to a better understanding of the current technical and scientific roadblocks to progress and how to overcome them. We expect the Study Program to elucidate unique advantages of space-based platforms and help to spur novel approaches, core technology development, and new mission concepts.

Our Study Program will be structured around the principal theme of diffuse spectral radio/mm/sub-mm observations that target atomic and molecular lines as tracers of matter in the pre- and inter-galactic medium and early structures. These lines and related scattering and other spectral signatures are present during recombination in the form of highly redshifted atomic recombination lines of H and He, and at subsequent times as molecular cooling lines (from e.g. H2), metal fine structure forbidden lines, and the rest- frame 21 cm HI hyperfine line. We foresee the potential for this Study to result in spin- off scientific and technical opportunities, including new avenues to probe the forest of anomalous spinning dust lines or detect counterparts to diffuse optical bands in the ISM.

Workshop Participants:

  • Yacine Ali-Haimoud - Caltech
  • Judd D Bowman - Caltech
  • Chris Carilli - National Radio Astronomy Osbervatory
  • Tzu-Ching Chang - University of Toronto
  • Ranga Chary - Caltech
  • Jens Chluba - University of Toronto
  • Asantha Cooray - University of California, Irvine
  • Angelica de Oliveira-Costa - Harvard-Smithsonian Center for Astrophysics
  • Roger Deane - University of Oxford
  • Olivier P Dore - JPL
  • Steve Furlanetto - UCLA
  • Christopher M Hirata - Caltech
  • Dayton L Jones - JPL
  • Charles R Lawrence - JPL
  • Louis Levenson - Caltech
  • Philip M Lubin - UC Santa Barbara
  • Tim J Pearson - Caltech
  • Jonathan Pritchard - Harvard-Smithsonian Center for Astrophysics
  • Steve Rawlings - University of Oxford
  • Tony Readhead - Caltech
  • Dominik Riechers - Caltech
  • Mike D Seiffert - Jet Propulsion Laboratory

Short Course Presentations

Jens Chluba

Atomic lines from the recombination era, Compton parameter (y), and chemical potential (mu)
(17 MB .pdf)

Chris Hirata

Stuff other than H I in the Early Universe
(454 KB .pdf)

Steve Furlanetto

The Redshifted 21 cm signal
(15 MB .pdf)

Mike Seiffert

CMB spectral distortion constraints from ground, sub-orbital, and space experiments
(2.5 KB .pdf)

Workshop Presentations

Chris Carilli

Metal and molecular lines from the ALMA and EVLA perspective
(8.24 MB .pdf)

Tzu-Ching Chang

Lessons from 21 cm intensity mapping with the GBT
(1.7 MB .pdf)

Ranga Ram Chary

What Constraints Can we Get on the Reionization History from the Optical/Near-Infrared?
(1.25 MB .pdf)

Jens Chluba

The Cosmological Recombination Spectrum: So What?
(15 MB .pdf)

Olivier Dore
New signals in the frequency dependent angular power spectrum?
(3.2 MB .pdf)

Yacine Ali-Haimoud

Foregrounds and secondary science: Spinning dust radiation
(4 MB .pdf)

Angelica de Oliveira-Costa
Microwave Foregrounds
(14 MB .pdf)

Jonathan Pritchard

Lessons from constraining global 21 cm spectrum in the presence of foregrounds
(5 MB .pdf)