Survey of planetary nebulae at 30 GHz with OCRA-p
| Autor: | Peter N. Wilkinson, Ian Browne, S. R. Lowe, A. J. Kus, Katy Lancaster, Mark Birkinshaw, Marcin P. Gawronski, Michael W. Peel, Richard J. Davis, R. Feiler, E. Pazderski, B. M. Pazderska |
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| Rok vydání: | 2009 |
| Předmět: |
Physics
Radiometer Spinning dust Astrophysics::High Energy Astrophysical Phenomena Astrophysics::Instrumentation and Methods for Astrophysics FOS: Physical sciences Flux Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies Planetary nebula Declination Spectral line law.invention Telescope Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science law Astrophysics of Galaxies (astro-ph.GA) Astrophysics::Earth and Planetary Astrophysics Right ascension Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics |
| Zdroj: | Astronomy & Astrophysics. 498:463-470 |
| ISSN: | 1432-0746 0004-6361 |
| DOI: | 10.1051/0004-6361/200811369 |
| Popis: | We report the results of a survey of 442 planetary nebulae at 30 GHz. The purpose of the survey is to develop a list of planetary nebulae as calibration sources which could be used for high frequency calibration in future. For 41 PNe with sufficient data, we test the emission mechanisms in order to evaluate whether or not spinning dust plays an important role in their spectra at 30 GHz. The 30-GHz data were obtained with a twin-beam differencing radiometer, OCRA-p, which is in operation on the Torun 32-m telescope. Sources were scanned both in right ascension and declination. We estimated flux densities at 30 GHz using a free-free emission model and compared it with our data. The primary result is a catalogue containing the flux densities of 93 planetary nebulae at 30 GHz. Sources with sufficient data were compared with a spectral model of free-free emission. The model shows that free-free emission can generally explain the observed flux densities at 30 GHz thus no other emission mechanism is needed to account for the high frequency spectra. Comment: 10 pages, 7 Postscript figures, to be published in A&A |
| Databáze: | OpenAIRE |
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