ALMA Observations of the Solar Chromosphere on the Polar Limb

Abstract

We report the results of the Atacama Large Millimeter/sub-millimeter Array (ALMA) observations of the solar chromosphere on the southern polar limb. Coordinated observations with the Interface Region Imaging Spectrograph (IRIS) are also conducted. ALMA provided unprecedented high spatial resolution in the millimeter band ($\approx$ 2.0 arcsec) at 100 GHz frequency with a moderate cadence (20 s). The results are as follows: (1) The ALMA 100 GHz images show saw-tooth patterns on the limb, and a comparison with SDO/AIA 171Å images shows a good correspondence of the limbs with each other. (2) The ALMA 100 GHz movie shows a dynamic thorn-like structure elongating from the saw-tooth patterns on the limb, with lengths reaching at least 8 arcsec, thus suggesting jet-like activity in the ALMA microwave range. These ALMA jets are in good correspondence with IRIS jet clusters. (3) A blob ejection event is observed. By comparing with the IRIS Mg II slit-jaw images, the trajectory of the blob is located along the spicular patterns.

arXiv commentAccepted for publication in The Astrophysical Journal

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• The Interface Region Imaging Spectrograph (IRIS)
• The Atacama Large Millimeter/submillimeter Array
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• Variation of Solar Microwave Spectrum in the Last Half Century
• Multi-Wavelength Observation of Electron Acceleration in the 2006 December 13 Flare
• Unusual migration of the prominence activities in the southern hemisphere during Cycle 23--24
• ALMA Discovery of Solar Umbral Brightness Enhancement at λ=3 mm

Cited by in corpus (7)

• Critical Science Plan for the Daniel K. Inouye Solar Telescope (DKIST)
• Solar Chromospheric Temperature Diagnostics: a joint ALMA-H$\alpha$ analysis
• The Sun at millimeter wavelengths I. Introduction to ALMA Band 3 observations
• ALMA and IRIS Observations of the Solar Chromosphere I: an On-Disk Type II Spicule
• High-frequency oscillations in small chromospheric bright features observed with ALMA
• A new view of the solar interface region from the Interface Region Imaging Spectrograph (IRIS)
• The Solar ALMA Science Archive (SALSA)