Ba II 4554 Å speckle imaging as solar Doppler diagnostic

Autor:	Sütterlin, P., Rutten, R.J., Skomorovsky, V.I.
Jazyk:	angličtina
Rok vydání:	2001
Předmět:	atmosphere [Sun] photosphere [Sun] Natuur- en Sterrenkunde image processing [Techniques] Sun: photosphere Techniques: image processing faculae [Sun] miscellaneous [Instrumentation] Sun: faculae plages Sun: atmosphere Instrumentation: miscellaneous
Zdroj:	Astronomy & Astrophysics. Elsevier Astronomy & Astrophysics
Popis:	We present observations testing the Dopplergram capability of a narrow-band (80 mÅ) Lyot filter imaging the solar surface in the wings of the Ba II 4554 Å resonance line in combination with speckle reconstruction to obtain high angular resolution. The Ba II line is found to be an excellent tool for high-resolution Doppler mapping thanks to opacity insensitivity to temperature variations and line-width insensitivity to thermal broadening. The resulting Dopplergrams show concentrated downflows of 1.2-2.2 km s^-1 in intergranular lanes that probably mark magnetic fluxtubes. Two-wavelength profile sampling is found to suffice for high-resolution Dopplergram construction. The filter will be installed as part of a multi-wavelength speckle imaging system on the new Dutch Open Telescope.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=dedup_wf_001::81ad4b2bcc9b1e99664e71e5b192426f https://dspace.library.uu.nl/handle/1874/1177 Zobrazit plný text záznamu