Astrophysical Constraints from the SARAS3 non-detection of the Cosmic Dawn Sky-Averaged 21-cm Signal

Autor: Bevins, H. T. J., Fialkov, A., Acedo, E. de Lera, Handley, W. J., Singh, S., Subrahmanyan, R., Barkana, R.
Rok vydání: 2022
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1038/s41550-022-01825-6
Popis: Observations of the redshifted 21-cm line of atomic hydrogen have resulted in several upper limits on the 21-cm power spectrum and a tentative detection of the sky-averaged signal at $z\sim17$. Made with the EDGES Low-Band antenna, this claim was recently disputed by the SARAS3 experiment, which reported a non-detection and is the only available upper limit strong enough to constrain cosmic dawn astrophysics. We use these data to constrain a population of radio-luminous galaxies $\sim 200$ million years after the Big Bang ($z\approx 20$). We find, using Bayesian data analysis, that the data disfavours (at 68% confidence) radio-luminous galaxies in dark matter halos with masses of $4.4\times10^{5}$ M$_\odot \lesssim M \lesssim 1.1\times10^{7}$M$_\odot$ (where $M_\odot$ is the mass of the Sun) at $z = 20$ and galaxies in which $>5$% of the gas is converted into stars. The data disfavour galaxies with radio luminosity per star formation rate of $L_\mathrm{r}/\mathrm{SFR} \gtrsim 1.549 \times 10^{25}$ W Hz$^{-1}$M$_\odot^{-1}$ yr at 150 MHz, a thousand times brighter than today, and, separately, a synchrotron radio background in excess of the CMB by $\gtrsim 6%$ at 1.42 GHz.
Comment: Published in Nature Astronomy
Databáze: arXiv