An absorption profile centred at 78 megahertz in the sky-averaged spectrum
Artículo de publicación ISI
| Autores principales: | , , , , |
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| Formato: | Artículo (Article) |
| Idioma: | Inglés (English) |
| Publicado: |
Springer
2020
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| Materias: | |
| Acceso en línea: | http://repositoriodigital.ucsc.cl/handle/25022009/1527 |
| _version_ | 1765785023594627072 |
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| author | Bowman, Judd D. Rogers, Alan E. E. Monsalve, Raúl Mozdzen, Thomas J. Mahesh, Nivedita |
| author_facet | Bowman, Judd D. Rogers, Alan E. E. Monsalve, Raúl Mozdzen, Thomas J. Mahesh, Nivedita |
| author_sort | Bowman, Judd D. |
| collection | Repositorio |
| coutry_str | Chile |
| description | Artículo de publicación ISI |
| first_indexed | 2023-05-13T13:17:05Z |
| format | Artículo (Article) |
| id | ir-25022009-1527 |
| institution | Universidad Católica de la Santísima Concepción |
| language | Inglés (English) |
| last_indexed | 2023-05-13T13:17:05Z |
| publishDate | 2020 |
| publisher | Springer |
| record_format | dspace |
| spelling | ir-25022009-15272023-01-31T07:48:02Z An absorption profile centred at 78 megahertz in the sky-averaged spectrum Bowman, Judd D. Rogers, Alan E. E. Monsalve, Raúl Mozdzen, Thomas J. Mahesh, Nivedita Astronomical instrumentation Cosmology Stars Artículo de publicación ISI After stars formed in the early Universe, their ultraviolet light is expected, eventually, to have penetrated the primordial hydrogen gas and altered the excitation state of its 21-centimetre hyperfine line. This alteration would cause the gas to absorb photons from the cosmic microwave background, producing a spectral distortion that should be observable today at radio frequencies of less than 200 megahertz1. Here we report the detection of a flattened absorption profile in the sky-averaged radio spectrum, which is centred at a frequency of 78 megahertz and has a best-fitting full-width at half-maximum of 19 megahertz and an amplitude of 0.5 kelvin. The profile is largely consistent with expectations for the 21-centimetre signal induced by early stars; however, the best-fitting amplitude of the profile is more than a factor of two greater than the largest predictions2. This discrepancy suggests that either the primordial gas was much colder than expected or the background radiation temperature was hotter than expected. Astrophysical phenomena (such as radiation from stars and stellar remnants) are unlikely to account for this discrepancy; of the proposed extensions to the standard model of cosmology and particle physics, only cooling of the gas as a result of interactions between dark matter and baryons seems to explain the observed amplitude3. The low-frequency edge of the observed profile indicates that stars existed and had produced a background of Lyman-α photons by 180 million years after the Big Bang. The high-frequency edge indicates that the gas was heated to above the radiation temperature less than 100 million years later. 2020-05-18T21:13:55Z 2020-05-18T21:13:55Z 2018-03 Article Nature, volume 555, pages 67–70 (2018) 1476-4687 http://repositoriodigital.ucsc.cl/handle/25022009/1527 en Springer https://doi.org/10.1038/nature25792 |
| spellingShingle | Astronomical instrumentation Cosmology Stars Bowman, Judd D. Rogers, Alan E. E. Monsalve, Raúl Mozdzen, Thomas J. Mahesh, Nivedita An absorption profile centred at 78 megahertz in the sky-averaged spectrum |
| title | An absorption profile centred at 78 megahertz in the sky-averaged spectrum |
| title_full | An absorption profile centred at 78 megahertz in the sky-averaged spectrum |
| title_fullStr | An absorption profile centred at 78 megahertz in the sky-averaged spectrum |
| title_full_unstemmed | An absorption profile centred at 78 megahertz in the sky-averaged spectrum |
| title_short | An absorption profile centred at 78 megahertz in the sky-averaged spectrum |
| title_sort | absorption profile centred at 78 megahertz in the sky-averaged spectrum |
| topic | Astronomical instrumentation Cosmology Stars |
| url | http://repositoriodigital.ucsc.cl/handle/25022009/1527 |
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