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First results on the Epoch of Reionization from First Light with SARAS 2
- Publication Year :
- 2017
- Publisher :
- arXiv, 2017.
-
Abstract
- Long wavelength spectral distortions in the Cosmic Microwave Background arising from the 21-cm transition in neutral Hydrogen are a key probe of Cosmic Dawn and the Epoch of Reionization. These features may reveal the nature of the first stars and ultra-faint galaxies that transformed the spin temperature and ionization state of the primordial gas. SARAS~2 is a spectral radiometer purposely designed for precision measurement of these monopole or all-sky global 21-cm spectral distortions. We use 63~hr night time observing of the radio background in the frequency band 110-200~MHz with the radiometer deployed at the Timbaktu Collective in Southern India to derive likelihoods for plausible redshifted 21-cm signals predicted by theoretical models. First light with SARAS 2 disfavors the class of models that feature weak X-ray heating (with $f_X \leq 0.1$) and rapid reionization (with peak $\frac{dT_b}{dz} \geq 120~\textrm{mK per unit redshift interval}$ ).<br />Comment: 6 pages, 5 figures, accepted for publication in ApJ Letters
- Subjects :
- Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Cosmic microwave background
Cosmic background radiation
FOS: Physical sciences
Astrophysics
cosmic background radiation
Astrophysics::Cosmology and Extragalactic Astrophysics
01 natural sciences
0103 physical sciences
dark ages, reionization, first stars
010303 astronomy & astrophysics
Reionization
Instrumentation and Methods for Astrophysics (astro-ph.IM)
Astrophysics::Galaxy Astrophysics
Physics
Radiometer
COSMIC cancer database
010308 nuclear & particles physics
Astrophysics::Instrumentation and Methods for Astrophysics
Astronomy and Astrophysics
Galaxy
Redshift
Stars
Space and Planetary Science
cosmology: observations
methods: observational
Astrophysics - Instrumentation and Methods for Astrophysics
Astrophysics - Cosmology and Nongalactic Astrophysics
Subjects
Details
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....72ae5427608a25b47a4e7734f84aae79
- Full Text :
- https://doi.org/10.48550/arxiv.1703.06647