Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published February 15, 2019 | Accepted Version
Report Open

The First Billion Years

Abstract

Spectral measurements of atomic and molecular lines embedded in the cosmic microwave background (CMB) have the potential to open entirely new probes of the early Universe. Two avenues are of great interest: 1) Spectral line deviations from the CMB blackbody spectrum will enable the study of hydrogen and helium recombination physics during and before the time of the surface of last scattering, and could provide the potential for game-changing discoveries by testing dark matter annihilation in the redshift range 6000> z > 1000, by allowing a test of the time-dependence of the fine-structure constant at a critical epoch, and by testing inflation models using an independent method. 2) Extension of CMB anisotropy measurements to detect unresolved spectral line emission from starforming galaxies during reionization (6 < z < 10) would directly delineate the large-scale structure of the galaxies responsible for reionizing the Universe and provide the only foreseeable measurements on scales sufficiently large to compare with upcoming observations of reionization by way of the redshifted hydrogen 21 cm line. CO, [C II], and Ly-a lines were investigated as promising targets. CO and [C II] line transitions emerged as particularly compelling. The two science objectives identified in the Program share some common core technological requirements based on the shared need for approximately 1000-element feed arrays followed by broadband, highresolution spectral correlators. The technical requirements lead to a roadmap for development of large feed arrays beginning with applications in a ground-based CO mapping instrument and leading to a spaceborne recombination-line all-sky spectrometer. The key technical issues include compact and light-weight integrated spectral dual-polarization inexpensive receiver modules, large high-resolution spectral correlators (analog and/or digital), and light-weight feeds. In parallel we recommend long-term investigations into high precision calibrators and calibration techniques that will be required for the recombination line instrument. A second roadmap addresses technical developments required for a 2-D spectroscopic instrument for [C II] mapping.

Attached Files

Accepted Version - Billion_final_report.pdf

Files

Billion_final_report.pdf
Files (8.1 MB)
Name Size Download all
md5:9e34e085ae00629b25e5fb68f4f998d5
8.1 MB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 20, 2023