2012/01/09 by L. J. Greenhill, G. Bernardi, Greenhill, L. J. +1 · 4 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Brightness #Brightness temperature #Cosmic microwave background #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxy #HERA #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Optics #Particle physics #Physics #Radio Astronomy Observations and Technology #Redshift #Reionization #Superconducting and THz Device Technology #astro-ph.CO #astro-ph.IM
paper · pdf · doi:10.48550/arxiv.1201.1700
8 pages, 4 figures, 1 table. Invited review to the 11th Asian-Pacific Regional IAU Meeting 2011, NARIT Conference Series, Vol. 1 eds. S. Komonjinda, Y. Kovalev, and D. Ruffolo (2012)
arxiv created 2012/01/09 · openalex publication_date 2012/01/09 · arxiv updated 2012/01/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
There are few data available with which to constrain the thermal history of the intergalactic medium (IGM) following global recombination. Thus far, most constraints flow from analyses of the Cosmic Microwave Background and optical spectroscopy along a few lines of sight. However, direct study of the IGM in emission or absorption against the CMB via the 1S hyperfine transition of Hydrogen would enable broad characterization thermal history and source populations. New generations of radio arrays are in development to measure this line signature. Bright foreground emission and the complexity of instrument calibration models are significant hurdles. How to optimize these is uncertain, resulting in a diversity in approaches. We discuss recent limits on line brightness, array efforts including the new Large Aperture Experiment to Detect the Dark Ages (LEDA), and the next generation Hydrogen Reionization Array (HERA) concept.