Radiative Transfer in Solar Prominences

Heinzel, P.

doi:10.1007/978-3-319-10416-4_5

Cited by 34 publications

(21 citation statements)

References 32 publications

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“…Gouttebroze, Heinzel, and Vial, 1993) where the prominence was considered as an isothermal and isobaric layer. More recently, prominence-corona transition regions (PCTR) have been grafted to the homogeneous layer on the basis of magnetohydrostatic (mhs) equilibrium by Anzer and Heinzel (1999) and then consistent mhs models of threads have been combined with the addition of inhomogeneous layers (Heinzel, Anzer, and Gunár, 2005); for comprehensive reviews of this modeling, see Labrosse et al (2010), Gunár (2014), Labrosse (2015) and Heinzel (2015). In all these recent models, there is basically a cool core (T ≈ 10 000 K) and a PCTR where physical quantities vary drastically up to the corona itself where the density is low enough for all the lines and continua of all elements (including hydrogen) to be optically thin.…”

Section: Non-lte Computationsmentioning

confidence: 99%

Neutral Hydrogen and Its Emission Lines in the Solar Corona

Vial

Chane-Yook

2016

Sol Phys

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Since the Lα rocket observations of (Gabriel, Solar Phys. 21, 392, 1971), it has been realized that the hydrogen (H) lines could be observed in the corona and offer an interesting diagnostic for the temperature, density, and radial velocity of the coronal plasma. Moreover, various space missions have been proposed to measure the coronal magnetic and velocity fields through polarimetry in H lines. A necessary condition for such measurements is to benefit from a sufficient signal-to-noise ratio. The aim of this article is to evaluate the emission in three representative lines of H for three different coronal structures. The computations have been performed with a full non-local thermodynamicequilibrium (non-LTE) code and its simplified version without radiative transfer. Since all collisionnal and radiative quantities (including incident ionizing and exciting radiation) are taken into account, the ionization is treated exactly. Profiles are presented at two heights (1.05 and 1.9 solar radii, from Sun center) in the corona, and the integrated intensities are computed at heights up to five solar radii. We compare our results with previous computations and observations (e.g. Lα from UVCS) and find a rough (model-dependent) agreement. Since the Hα line is a possible candidate for ground-based polarimetry, we show that in order to detect its emission in various coronal structures, it is necessary to use a very narrow (less than 2Å wide) bandpass filter.

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Section: Non-lte Computationsmentioning

confidence: 99%

Neutral Hydrogen and Its Emission Lines in the Solar Corona

Vial

Chane-Yook

2016

Sol Phys

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“…In particular, the abiding presence of a prominence implies a magnetic structure that can provide sustained gravitational support and thermal isolation. Several excellent review chapters within the recent book Solar Prominences (Engvold and Vial 2015) cover our theoretical understanding of the origins of such magnetic structures and their evolution on a variety of temporal and spatial scales (Mackay 2015), the energetic processes associated with prominence formation and visibility (Gilbert 2015; Heinzel 2015; Karpen 2015), and the mechanisms responsible for the ultimate fate of many prominences as the cores of solar eruptions (Fan 2015). Prominence observations and interpretation are also well-covered by other chapters within that book (Ballester 2015; Engvold 2015; Gibson 2015; Gopalswamy 2015; Kucera 2015; Labrosse 2015; López Ariste 2015; Lugaz 2015; Martin 2015; Parenti 2015; Webb 2015) and by the Living Reviews on “Prominence Oscillations” by Arregui et al.…”

Section: Introductionmentioning

confidence: 99%

Solar prominences: theory and models

Gibson

2018

Living Rev Sol Phys

113

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Magnetic fields suspend the relatively cool material of solar prominences in an otherwise hot corona. A comprehensive understanding of solar prominences ultimately requires complex and dynamic models, constrained and validated by observations spanning the solar atmosphere. We obtain the core of this understanding from observations that give us information about the structure of the “magnetic skeleton” that supports and surrounds the prominence. Energetically-sophisticated magnetohydrodynamic simulations then add flesh and blood to the skeleton, demonstrating how a thermally varying plasma may pulse through to form the prominence, and how the plasma and magnetic fields dynamically interact.

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“…4 are simplified solutions to the radiative transfer equation (see e.g. Labrosse et al 2010;Heinzel 2015), assuming a constant line source function and an emission normal to the slab representing the filament/prominence. For observed values of (F * + FP )/F * of the V374 Peg event see table 1.…”

Section: Modelingmentioning

confidence: 99%

Modeling Balmer line signatures of stellar CMEs

Leitzinger,

Odert,

Heinzel

2022

Preprint

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From the Sun we know that coronal mass ejections (CMEs) are a transient phenomenon, often correlated with flares. They have an impact on solar mass-and angular momentum loss, and therefore solar evolution, and make a significant part of space weather. The same is true for stars, but stellar CMEs are still not well constrained, although new methodologies have been established, and new detections presented in the recent past. So far, probable detections of stellar CMEs have been presented, but their physical parameters which are not directly accessible from observations, such as electron density, optical thickness, temperature, etc., have been so far not determined for the majority of known events. We apply cloud modeling, as commonly used on the Sun, to a known event from the literature, detected on the young dMe star V374 Peg. This event manifests itself in extra emission on the blue side of the Balmer lines. By determining the line source function from 1D NLTE modeling together with the cloud model formulation we present distributions of physical parameters of this event. We find that except for temperature and area all parameters are at the upper range of typical solar prominence parameters. The temperature and the area of the event were found to be higher than for typical solar prominences observed in Balmer lines. We find more solutions for the filament than for the prominence geometry. Moreover we show that filaments can appear in emission on dMe stars contrary to the solar case.

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Radiative Transfer in Solar Prominences

Cited by 34 publications

References 32 publications

Neutral Hydrogen and Its Emission Lines in the Solar Corona

Neutral Hydrogen and Its Emission Lines in the Solar Corona

Solar prominences: theory and models

Modeling Balmer line signatures of stellar CMEs

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