Tight constraints on the excess radio background at z = 9.1 from LOFAR
| Autor: | Raghunath Ghara, Luitje Koopmans, Anastasia Fialkov, Abhik Ghosh, Ilian T. Iliev, Garrelt Mellema, Saleem Zaroubi, Rajesh Mondal, Florent Mertens, Sambit K. Giri, B. K. Gehlot, B. Ciardi, Vishambhar Pandey, Rennan Barkana, A. R. Offringa, C. Fling |
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| Přispěvatelé: | University of Zurich, Mondal, R, Fialkov, A, Astronomy, Kapteyn Astronomical Institute |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
530 Physics media_common.quotation_subject Cosmic microwave background first stars FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences 1912 Space and Planetary Science Ionization cosmology: theory 0103 physical sciences dark ages 010303 astronomy & astrophysics Reionization Astrophysics::Galaxy Astrophysics media_common Physics methods: statistical 010308 nuclear & particles physics Astrophysics::Instrumentation and Methods for Astrophysics Astronomy and Astrophysics LOFAR Universe diffuse radiation Stars 13. Climate action Space and Planetary Science 10231 Institute for Computational Science Dark Ages 3103 Astronomy and Astrophysics reionization Radio frequency Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Monthly Notices of the Royal Astronomical Society, 498(3), 4178-4191. Oxford University Press |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | The ARCADE2 and LWA1 experiments have claimed an excess over the Cosmic Microwave Background (CMB) at low radio frequencies. If the cosmological high-redshift contribution to this radio background is between 0.1% and 22% of the CMB at 1.42 GHz, it could explain the tentative EDGES Low-Band detection of the anomalously deep absorption in the 21-cm signal of neutral hydrogen. We use the upper limit on the 21-cm signal from the Epoch of Reionization ($z=9.1$) based on 141 hours of observations with LOFAR to evaluate the contribution of the high redshift Universe to the detected radio background. Marginalizing over astrophysical properties of star-forming halos, we find (at 95% C.L.) that the cosmological radio background can be at most 9.6% of the CMB at 1.42 GHz. This limit rules out strong contribution of the high-redshift Universe to the ARCADE2 and LWA1 measurements. Even though LOFAR places limit on the extra radio background, excess of $0.1-9.6$% over the CMB (at 1.42 GHz) is still allowed and could explain the EDGES Low-Band detection. We also constrain the thermal and ionization state of the gas at $z = 9.1$ and put limits on the properties of the first star-forming objects. We find that, in agreement with the limits from EDGES High-Band data, LOFAR data constrain scenarios with inefficient X-ray sources and cases where the Universe was ionized by stars in massive halos only. Published in Monthly Notices of the Royal Astronomical Society (MNRAS). Available at https://doi.org/10.1093/mnras/staa2422 |
| Databáze: | OpenAIRE |
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