90 research outputs found
ALMA as a prominence thermometer: First observations
We present first prominence observations obtained with ALMA in Band 3 at the
wavelength of 3 mm. High-resolution observations have been coaligned with the
MSDP H data from Wroclaw-Bialk\'{o}w large coronagraph at similar
spatial resolution. We analyze one particular co-temporal snapshot, first
calibrating both ALMA and MSDP data and then demonstrating a reasonable
correlation between both. In particular we can see quite similar fine-structure
patterns in both ALMA brightness temperature maps and MSDP maps of H
intensities. Using ALMA we intend to derive the prominence kinetic
temperatures. However, having current observations only in one band, we use an
independent diagnostic constraint which is the H line integrated
intensity. We develop an inversion code and show that it can provide realistic
temperatures for brighter parts of the prominence where one gets a unique
solution, while within faint structures such inversion is ill conditioned. In
brighter parts ALMA serves as a prominence thermometer, provided that the
optical thickness in Band 3 is large enough. In order to find a relation
between brightness and kinetic temperatures for a given observed H
intensity, we constructed an extended grid of non-LTE prominence models
covering a broad range of prominence parameters. We also show the effect of the
plane-of-sky filling factor on our results.Comment: 9 pages, 3 figures, accepted for publication in the The Astrophysical
Journal Letter
Observations and Modeling of Line Asymmetries in Chromospheric Flares
International audienc
Observations and Modeling of Line Asymmetries in Chromospheric Flares
International audienc
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