Measurement of the anisotropy power spectrum of the radio synchrotron background
| Autor: | Jack Singal, A. R. Offringa, D. M. Lucero, Shunsaku Horiuchi, S. Heston |
|---|---|
| Přispěvatelé: | Astronomy |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Astrophysics::High Energy Astrophysical Phenomena media_common.quotation_subject FOS: Physical sciences Synchrotron radiation Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics radio continuum law.invention Galactic halo law Sky brightness Anisotropy Instrumentation and Methods for Astrophysics (astro-ph.IM) Astrophysics::Galaxy Astrophysics media_common Physics Spectral density Astronomy and Astrophysics LOFAR Synchrotron radiation mechanisms Space and Planetary Science Sky general interferometric non-theal Astrophysics - Instrumentation and Methods for Astrophysics techniques Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Monthly Notices of the Royal Astronomical Society, 509(1), 114-121. Oxford University Press |
| ISSN: | 0035-8711 |
| Popis: | We present the first targeted measurement of the power spectrum of anisotropies of the radio synchrotron background, at 140 MHz where it is the overwhelmingly dominant photon background. This measurement is important for understanding the background level of radio sky brightness, which is dominated by steep-spectrum synchrotron radiation at frequencies below 0.5 GHz and has been measured to be significantly higher than that which can be produced by known classes of extragalactic sources and most models of Galactic halo emission. We determine the anisotropy power spectrum on scales ranging from 2 degrees to 0.2 arcminutes with LOFAR observations of two 18 square degree fields -- one centered on the Northern hemisphere coldest patch of radio sky where the Galactic contribution is smallest and one offset from that location by 15 degrees. We find that the anisotropy power is higher than that attributable to the distribution of point sources above 100 micro-Jy in flux. This level of radio anisotropy power indicates that if it results from point sources, those sources are likely at low fluxes and incredibly numerous, and likely clustered in a specific manner. Comment: 8 pages, 5 figures, published in MNRAS, updated to published version and typos removed |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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