Results from EDGES High-Band. III. New Constraints on Parameters of the Early Universe

Raul A. Monsalve, Anastasia Fialkov, Judd Bowman, Alan E.E. Rogers, Thomas J. Mozdzen, Aviad Cohen, Rennan Barkana, Nivedita Mahesh

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We present new constraints on parameters of cosmic dawn and the epoch of reionization derived from the EDGES High-Band spectrum (90-190 MHz). The parameters are probed by evaluating global 21 cm signals generated with the recently developed Global21cm tool. This tool uses neural networks trained and tested on ∼30,000 spectra produced with semi-numerical simulations that assume the standard thermal evolution of the cosmic microwave background and the intergalactic medium. From our analysis, we constrain at 68% (1) the minimum virial circular velocity of star-forming halos to V c <19.3 km s-1, (2) the X-ray heating efficiency of early sources to f X > 0.0042, and (3) the low-energy cutoff of the X-ray spectral energy distribution to ν min <2.3 keV. We also constrain the star formation efficiency (f ), the electron scattering optical depth (τ e), and the mean-free path of ionizing photons (R mfp). We recompute the constraints after incorporating into the analysis four estimates for the neutral hydrogen fraction from high-z quasars and galaxies, and a prior on τ e from Planck 2018. The largest impact of the external observations is on the parameters that most directly characterize reionization. Specifically, we derive the combined 68% constraints τ e <0.063 and R mfp > 27.5 Mpc. The external observations also have a significant effect on V c due to its degeneracy with τ e, while the constraints on f , f X, and ν min, remain primarily determined by EDGES.

Original languageEnglish (US)
Article number67
JournalAstrophysical Journal
Volume875
Issue number1
DOIs
StatePublished - Apr 10 2019

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universe
tool use
intergalactic media
thermal evolution
spectral energy distribution
energy
halos
cut-off
time measurement
microwaves
stars
simulation
x rays
parameter
distribution
analysis
effect
microwave

Keywords

  • cosmology: observations
  • early universe
  • galaxies: high-redshift
  • methods: data analysis

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Monsalve, R. A., Fialkov, A., Bowman, J., Rogers, A. E. E., Mozdzen, T. J., Cohen, A., ... Mahesh, N. (2019). Results from EDGES High-Band. III. New Constraints on Parameters of the Early Universe. Astrophysical Journal, 875(1), [67]. https://doi.org/10.3847/1538-4357/ab07be

Results from EDGES High-Band. III. New Constraints on Parameters of the Early Universe. / Monsalve, Raul A.; Fialkov, Anastasia; Bowman, Judd; Rogers, Alan E.E.; Mozdzen, Thomas J.; Cohen, Aviad; Barkana, Rennan; Mahesh, Nivedita.

In: Astrophysical Journal, Vol. 875, No. 1, 67, 10.04.2019.

Research output: Contribution to journalArticle

Monsalve, RA, Fialkov, A, Bowman, J, Rogers, AEE, Mozdzen, TJ, Cohen, A, Barkana, R & Mahesh, N 2019, 'Results from EDGES High-Band. III. New Constraints on Parameters of the Early Universe', Astrophysical Journal, vol. 875, no. 1, 67. https://doi.org/10.3847/1538-4357/ab07be
Monsalve, Raul A. ; Fialkov, Anastasia ; Bowman, Judd ; Rogers, Alan E.E. ; Mozdzen, Thomas J. ; Cohen, Aviad ; Barkana, Rennan ; Mahesh, Nivedita. / Results from EDGES High-Band. III. New Constraints on Parameters of the Early Universe. In: Astrophysical Journal. 2019 ; Vol. 875, No. 1.
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