High-resolution observations of the quiet sun at 6 centimeters using the Westerbork Synthesis Radio Telescope
1979; IOP Publishing; Volume: 234; Linguagem: Inglês
10.1086/157596
ISSN1538-4357
AutoresM. R. Kundu, A. Pramesh Rao, F. T. Erskine, J. D. Bregman,
Tópico(s)Adaptive optics and wavefront sensing
Resumoview Abstract Citations (34) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS High-resolution observations of the quiet sun at 6 centimeters using the Westerbork Synthesis Radio Telescope Kundu, M. R. ; Rao, A. P. ; Erskine, F. T. ; Bregman, J. D. Abstract High-spatial-resolution (∼6") observations of the quiet Sun were made at 6 cm with the Westerbork Synthesis Radio Telescope. A 10' × 10' field of the central disk region observed on 1976 June 16 was synthesized. We show the first radio map of the supergranulation network. Numerical autocorrelation of the radio map indicated a radio "network" width ∼11,000 km and a radio "cell" spacing ∼32,000 km. The brightness temperature of typical network elements is ∼2.5 × l04 K, while that of the radio cells is ∼1.5 × l04 K. The contrast between the radio network and cells is ∼1.7:1 which is intermediate to that of the Ca+ K network and Lα network. The radio map was compared with a Ca+ K spectroheliogram of the same region on the same day. On 1976 June 17, the four limbs of the Sun were also observed in an attempt to synthesize the limb and study the extent and symmetry of limb brightening. The results show that limb brightening is seen both in the north-south and east-west directions, contrary to earlier low-resolution measurements which showed limb brightening only in the east-west direction. The peak of the limb brightening appears ∼15" outside the white-light disk and the peak limb temperature is ∼40% greater than the mean disk temperature. Publication: The Astrophysical Journal Pub Date: December 1979 DOI: 10.1086/157596 Bibcode: 1979ApJ...234.1122K Keywords: Centimeter Waves; High Resolution; Limb Darkening; Radio Observation; Radio Telescopes; Solar Granulation; Autocorrelation; Brightness Temperature; Cross Correlation; Solar Atmosphere; Solar Instruments; Spectroheliographs; Solar Physics full text sources ADS |
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