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The Murchison Widefield Array (MWA) team has derived new upper limits on the spherically averaged power spectrum of the 21-cm signal at six redshifts in the range $z approx 6.5-8.7$. We use these upper limits and a Bayesian inference framework to derive constraints on the ionization and thermal state of the intergalactic medium (IGM) as well as on the strength of a possible additional radio background. We do not find any constraints on the state of the IGM for $zgtrsim 7.8$ if no additional radio background is present. In the presence of such a radio background, the 95 per cent credible intervals of the disfavoured models at redshift $gtrsim 6.5 $ correspond to an IGM with a volume averaged fraction of ionized regions below 0.6 and an average gas temperature $lesssim 10^3$ K. In these models, the heated regions are characterised by a temperature larger than that of the radio background, and by a distribution with characteristic size $lesssim 10$ $h^{-1}$ Mpc and a full width at half maximum (FWHM) of $lesssim 30$ $h^{-1}$ Mpc. Within the same credible interval limits, we exclude an additional radio background of at least $0.008%$ of the CMB at 1.42 GHz.
We derive constraints on the thermal and ionization states of the intergalactic medium (IGM) at redshift $approx$ 9.1 using new upper limits on the 21-cm power spectrum measured by the LOFAR radio-telescope and a prior on the ionized fraction at that
The motion of the solar system with respect to the cosmic rest frame modulates the monopole of the Epoch of Reionization 21-cm signal into a dipole. This dipole has a characteristic frequency dependence that is dominated by the frequency derivative o
A major goal of observational and theoretical cosmology is to observe the largely unexplored time period in the history of our universe when the first galaxies form, and to interpret these measurements. Early galaxies dramatically impacted the gas ar
Heating of neutral gas by energetic sources is crucial for the prediction of the 21 cm signal during the epoch of reionization (EoR). To investigate differences induced on statistics of the 21 cm signal by various source types, we use five radiative
The high-redshift 21 cm signal from the Epoch of Reionization (EoR) is a promising observational probe of the early universe. Current- and next-generation radio interferometers such as the Hydrogen Epoch of Reionization Array (HERA) and Square Kilome