Erratum: Spectral index of the Galactic foreground emission in the 50–87 MHz range
| Autor: | H. Garsden, Jayce Dowell, Anastasia Fialkov, Gianni Bernardi, Lincoln J. Greenhill, M. Spinelli, Danny C. Price |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 507:1491-1491 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stab2312 |
| Popis: | Total-power radiometry with individual meter-wave antennas is a potentially effective way to study the Cosmic Dawn ($z\sim20$) through measurement of sky brightness arising from the $21$~cm transition of neutral hydrogen, provided this can be disentangled from much stronger Galactic and extra-galactic foregrounds. In the process, measured spectra of integrated sky brightness temperature can be used to quantify the foreground emission properties. In this work, we analyze a subset of data from the Large-aperture Experiment to Detect the Dark Age (LEDA) in the range $50-87$~MHz and constrain the foreground spectral index $\beta$ in the northern sky visible from mid-latitudes. We focus on two zenith-directed LEDA radiometers and study how estimates of $\beta$ vary with local sidereal time (LST). We correct for the effect of gain pattern chromaticity and compare estimated absolute temperatures with simulations. We develop a reference dataset consisting of 14 days of optimal condition observations. Using this dataset we estimate, for one radiometer, that $\beta$ varies from $-2.55$ at LST~$ |
| Databáze: | OpenAIRE |
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