AN ACCURATE FLUX DENSITY SCALE FROM 1 TO 50 GHz
By Richard Perley, Bryan Butler. 2012
358 citations recorded by the source corpus.
We develop an absolute flux density scale for centimeter-wavelength astronomy by combining accurate flux density ratios determined by the Very Large Array between the planet Mars and a set of potential calibrators with the Rudy thermophysical emission model of Mars, adjusted to the absolute scale established by the Wilkinson Microwave Anisotropy Probe. The radio sources 3C123, 3C196, 3C286, and 3C295 are found to be varying at a level of less than ∼5% per century at all frequencies between 1 and 50 GHz, and hence are suitable as flux density standards. We present polynomial expressions for their spectral flux densities, valid from 1 to 50 GHz, with absolute accuracy estimated at 1%–3% depending on frequency. Of the four sources, 3C286 is the most compact and has the flattest spectral index, making it the most suitable object on which to establish the spectral flux density scale. The sources 3C48, 3C138, 3C147, NGC 7027, NGC 6542, and MWC 349 show significant variability on various timescales. Polynomial coefficients for the spectral flux density are developed for 3C48, 3C138, and 3C147 for each of the 17 observation dates, spanning 1983–2012. The planets Venus, Uranus, and Neptune are included in our observations, and we derive their brightness temperatures over the same frequency range.
Subfields: Astronomy and Astrophysics
View Paper: https://www.semanticscholar.org/paper/26627f0ebc964953cc9c07b9a144afe96e249119
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In Astronomy and Astrophysics
- A. Banday
- H. Eriksen
- F. Hansen
- P. Lilje
- Julien Lesgourgues
- G. Efstathiou
- Benjamin Dan Wandelt
- K. G'orski
Citations in the corpus
- Planck2013 results. XXVIII. ThePlanckCatalogue of Compact Sources (2013, methodology): “The VLA flux density scale used in this comparison is the new one proposed by Perley & Butler (2013), based on observations of Mars.”
- Planck2015 results: XXVI. The SecondPlanckCatalogue of Compact Sources (2015, neutral): “For the flux-density scale of Perley & Butler (2013), employed at the VLA, this uncertainty is estimated to be 5%, and roughly the same level of precision may be assigned to the flux-density scale employed at ATCA.”
- An Accurate Flux Density Scale from 50 MHz to 50 GHz (2016, methodology): “Accurate measurements of a set of small-diameter radio sources by the VLA resulted in the Perley and Butler (2013) (herafter PB13) scale, which was placed on an absolute scale via VLA and WMAP observations of the planet Mars, utilizing a thermophysical model of that planet’s emission.”