Submillimetric & millimetric

• "Characteristics of Solar Active Regions Obtained from Observations on Millimeter Wavelengths"
  Khangil'Din, U. V., Soviet Astronomy, 8, 234, 1964
  One of the first observation of filaments in radio, brightness depression, λ=8mm.
• "3.5 mm depression features associated with Hα 'disparitions brusques' "
  Kundu, M. R. & Lantos, P., Sol. Phys., 52, 393, 1977
  Brightness depression observed at the location of Hα filaments. The depression still exists after the eruption.
• "Observations of solar filaments at 8, 15, 22 and 43 GHz"
  Schmahl, E. J., Bobrowsky, M. & Kundu, M. R., Sol. Phys., 71, 311, 1981
  Brightness depressions mainly due to absorption by filament material.
• "Dark filaments observed at 8.3 mm and 3.1 mm wavelengths"
  Hiei, E., Ishiguro, M., Kosugi, T. & Shibasaki, K., NASA Conf. Publ., NASA CP-2442, 109, 1986
  Brightness depressions associated with neutral lines sometimes without the existence of filaments.
• "Large-scale patterns on the sun observed in the millimetric wavelength range"
  Vrsnak, B., Pohjolainen, S., Urpo, S., Terasranta, H., Brajsa, R., Ruzdjak, V., Mouradian, Z., & Jurac, S., Sol. Phys., 137, 67, 1992
  Association between radio depression and filaments is true but on average only. (comparison of carrington rotation maps)
• "A study of solar prominences near λ=1 mm"
  Bastian, T.S., Ewell, M. W. & Zirin, H., ApJ, 418, 510, 1993
  Filament associated with weak brightness depression, poor contrast, optically thin.

Centimetric

• "Radio Maps of the Sun at λ=1.95 cm"
  Chiuderi Drago, F., Felli, M., Sol. Phys., 14, 171, 1970
  λ=1.95 cm. Observation: brightness depression. Interpretation: lack of coronal emission due to the filament material.
• "On the structure of filaments from centimeter and millimeter observations"
  Butz, M., Fürst, E., Hirth, W., Kundu, M. R., Sol. Phys., 45, 125, 1975
  λ=2 cm. Observation: brightness depression. Interpretation: transition region.
• "Limb Brightening and Dark Features Observed at 6cm Wavelength"
  Chiuderi-Drago, F., Fürst, E., Hirth, W., Lantos, P., A&A, 39, 429, 1975
  λ=6 cm. Observation: brightness depression. Interpretation: transition region.
• "Study of a filament with a circularly polarized beam at 3.8 cm"
  Straka, R. M., Papagiannis, M. D., Kogut, J. A., Sol. Phys., 45, 131, 1975
  λ=3.8 cm. Observation: brightness depression. Interpretation: cavity.
• "A study of filament transition sheath from radio observations"
  Rao, A. P., Kundu, M. R., Sol. Phys., 55, 161, 1977
  λ=1.4, 2, 3.8 cm. Observations: brightness depression. Interpretation: transition region.
• "Multifrequency observations of solar filaments at centimeter wavelengths"
  Kundu, M. R., Fürst, E., Hirth, W., Butz, M., A&A, 1978, 62, 431
  λ=1.2, 2.8, 6, 11 cm. Observations: brightness depression. Interpretation: cavity.
• "Prominences at centimetric and millimetric wavelengths. I - Size and spectrum of the radio filaments"
  Raoult, A., Lantos, P. & Fuerst, E., Sol. Phys., 61, 335, 1979
  Compilation of different published observation. Deconvolved radio brightness depression are of the size of Hα filaments.
• "Prominences at centimetric and millimetric wavelengths. II - Radio diagnostic of the prominences"
  Lantos, P. & Raoult, A., Sol. Phys., 66, 275, 1980
  Analysis of previous reference. Brightness depression due to transition region.
• "Solar Quiescent Prominences at 10.7 GHz"
  Bracewell, R. N. & Graf, W., Nature, 290, 758, 1981
  λ= 2.8 cm. Observation: brightness depression + brightening. Interpretation: depression linked to the cavity, brightening over the filament.
• "The sun at 1.4 GHz - Intensity and polarization"
  Dulk, G. A. & Gary, D. E., A&A, 124, 103, 1983
  λ= 21 cm. Observation: brightness depression. Interpretation: cavity?
• "The microwave structure of quiescent solar filaments at high resolution"
  Gary, D. E., NASA Conf. Publ., NASA CP-2442, 121, 1986
  λ= 2, 6, 20.6 cm. Observations: brightness depression. Interpretation: cavity (6 & 20.6 cm)
• "A study of solar filaments from high resolution microwave observations"
  Kundu, M. R., Melozzi, M. & Shevgaonkar, R. K., A&A, 167, 166
  λ= 6, 20 cm. Observations: brightness depression + brightening. Interpretation: cavity + transition region.
• "Radio observations of prominences"
  Chiuderi Drago, F., Proceedings of the 117th Colloquium of IAU, 70, 1990
  Review paper & modelling of the radio emission of the transition region.
• "Joint EUV/Radio Observations of a Solar Filament"
  Chiuderi Drago, F., Alissandrakis, C. E., Bastian, T., Bocchialini, K., Harrison, R. A., Sol. Phys., 199, 115, 2001
  λ=1.76, 3.6, 6.1, 20.6 cm. Observations: brightness depression. Interpretation: transition region.

Metric

• "Solar Coronal Streamers Observed at 169 MHz with the Nançay East-West Radioheliograph"
  Axisa, F., Avignon, Y., Martres, M. J., Pick, M. & Simon, P., Sol. Phys., 19, 110, 1971
  λ= 178 cm. Observation: source. Interpretation: streamer.
• "The Structure of the Middle Corona from Observations at 80 and 160 MHz"
  Dulk, G. A. & Sheridan, K., V., Sol. Phys., 36, 191, 1974
  λ= 187, 375 cm. Observation: source. Interpretation: streamer.
• "Radio emission from quiescent solar filaments at 91.6 centimeter wavelength"
  Lang, K. R. & Willson, R. F., ApJ, 344L, 73L, 1989
  λ= 90 cm. Observation: emission. Interpretation: transition region.
• "Radio Metric Observations of Quiescent Filament Cavities"
  Marqué, C., ApJ, 602, 1037, 2004
  λ= 73 cm. Observation: brightness depression. Interpretation: cavity.