Temporal evolution of arch filaments as seen in He I 10 830 Å

Manrique, S. J. González; Kuckein, C.; Collados, M.; Denker, C.; Solanki, S. K.; Gömöry, P.; Verma, M.; Balthasar, H.; Lagg, A.; Diercke, A.

doi:10.1051/0004-6361/201832684

Cited by 14 publications

(29 citation statements)

References 55 publications

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“…Near the footpoints the profiles are strongly redshifted showing two velocity components. The presence of two components of velocity near the location of loop foot-points are also observed by Lagg et al (2007); Xu, Z. et al (2010);González Manrique et al (2018). The strong upflows near the tops of freshly emerged loops suggests that they carry cool material to the upper atmosphere, which is not yet heated to high temperature.…”

Section: Los Velocity In Photosphere and Chromospherementioning

confidence: 68%

“…The maximum height of AFS loop can varies between 5-25 Mm with a lifetime of about 30 minutes (Bruzek 1967). Near both foot-points of AFS supersonic downflow (30-50 km s −1 ), whereas near the middle part of loops strong upflows (2-20 km s −1 ) were observed by various authors (Bruzek 1967;Solanki et al 2003;González Manrique et al 2018). For the structure and dynamics of AFS see a review by Chou (1993) and references therein.…”

Section: Introductionmentioning

confidence: 99%

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Three-dimensional magnetic field structure of a flux-emerging region in the solar atmosphere

Yadav

Rodríguez

Baso

et al. 2019

A&A

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We analyze high-resolution spectropolarimetric observations of a flux emerging region (FER) in order to understand its magnetic and kinematic structure. Our spectropolarimetric observations in the He i 10830 Å spectral region of a FER are recorded with GRIS at the 1.5 m aperture GREGOR telescope. A Milne-Eddington based inversion code was employed to extract the photospheric information of the Si i spectral line, whereas the He i triplet line was analyzed with the Hazel inversion code, which takes into account the joint action of the Hanle and the Zeeman effect. The spectropolarimetric analysis of Si i line displays a complex magnetic structure near the vicinity of FER, where a weak (350 -600 G) and horizontal magnetic field was observed. In contrast to the photosphere, the analysis of the He i triplet presents a smooth variation of the magnetic field vector (ranging from 100 G to 400 G) and velocities across the FER. Moreover, we find supersonic downflows of ∼40 km s −1 appears near the foot points of loops connecting two pores of opposite polarity, whereas a strong upflows of 22 km s −1 appears near the apex of the loops. At the location of supersonic downflows in the chromosphere, we observed downflows of 3 km s −1 in the photosphere. Furthermore, non force-free field extrapolations were performed separately at two layers in order to understand the magnetic field topology of the FER. We determine, using extrapolations from the photosphere and the observed chromospheric magnetic field, that the average formation height of the He i triplet line is ∼2 Mm from the solar surface. The reconstructed loops using photospheric extrapolations along an arch filament system have a maximum height of ∼10.5 Mm from the solar surface with a foot-points separation of ∼19 Mm, whereas the loops reconstructed using chromospheric extrapolations are around ∼8.4 Mm high from the solar surface with a foot-point separation of ∼16 Mm at the chromospheric height. The magnetic topology in the FER suggests the presence of small-scale loops beneath the large loops. Under suitable conditions, due to magnetic reconnection, these loops can trigger various heating events in the vicinity of the FER.

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Section: Los Velocity In Photosphere and Chromospherementioning

confidence: 68%

Section: Introductionmentioning

confidence: 99%

Three-dimensional magnetic field structure of a flux-emerging region in the solar atmosphere

Yadav

Rodríguez

Baso

et al. 2019

A&A

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“…Hence, the He I profiles are seen slightly in emission (Lagg et al 2007). On the contrary, Xu et al (2010) did not find any evidence for shocks in the He I triplet and, therefore, proposed that the shock occurs below the formation height of He I. This study is the continuation of González Manrique et al (2017bManrique et al ( , 2018, who studied the evolution of an AFS in He I. The goal of the present study is to follow the evolution of the plasma flows across several heights at the footpoints of an AFS.…”

Section: Introductionmentioning

confidence: 74%

“…The spectral region observed with GRIS comprises the photospheric Ca I 10839 Å and Si I 10827 Å lines, as well as the chromospheric He I 10830 Å triplet among others. González Manrique et al (2017bManrique et al ( , 2018 studied the same data set of GRIS in the very fast spectroscopic mode in the He I 10830 Å spectral line. This study builds on the results of the previously mentioned papers.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Tracking Downflows from the Chromosphere to the Photosphere in a Solar Arch Filament System

Manrique

Kuckein

Yabar

et al. 2020

ApJ

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We study the dynamics of plasma along the legs of an arch filament system (AFS) from the chromosphere to the photosphere, observed with high-cadence spectroscopic data from two ground-based solar telescopes: the GREGOR telescope (Tenerife) using the GREGOR Infrarred Spectrograph (GRIS) in the He I 10830 Å range and the Swedish Solar Telescope (La Palma) using the CRisp Imaging Spectro-Polarimeter to observe the Ca II 8542 Å and Fe I 6173 Å spectral lines. The temporal evolution of the draining of the plasma was followed along the legs of a single arch filament from the chromosphere to the photosphere. The average Doppler velocities inferred at the upper chromosphere from the He I 10830 Å triplet reach velocities up to 20 -24 km s −1 , in the lower chromosphere and upper photosphere the Doppler velocities reach up to 11 km s −1 and 1.5 km s −1 in the case of the Ca II 8542 Å and Si I 10827 Å spectral lines, respectively. The evolution of the Doppler velocities at different layers of the solar atmosphere (chromosphere and upper photosphere) shows that they follow the same LOS velocity pattern, which confirm the observational evidence that the plasma drains towards the photosphere as proposed in models of AFSs. The Doppler velocity maps inferred from the lower photospheric Ca I 10839 Å or Fe I 6173 Å spectral lines do not show the same LOS velocity pattern. Thus, there is no evidence that the plasma reaches the lower photosphere. The observations and the nonlinear force-free field extrapolations demonstrate that the magnetic field loops of the AFS rise with time. We found flow asymmetries at different footpoints of the AFS. The NLFFF values of the magnetic field strength give us a clue to explain these flow asymmetries.

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“…8 around 09:00 UT). Thus, the chromospheric morphology of the EFR is similar to an arch-filament system (AFS, Bruzek 1967;Murabito et al 2017;González Manrique et al 2018); this chromospheric configuration is associated with emerging flux from the smallest granularscale (Centeno et al 2017) up to active regions. On top of this characteristic pattern, we also observed signatures of chromospheric ejecta (e.g., at around 09:10 UT in Fig.…”

Section: Chromospheric Response and Subsequent Evolutionmentioning

confidence: 97%

Emergence of small-scale magnetic flux in the quiet Sun

Kontogiannis

Tsiropoula²,

Tziotziou³

et al. 2020

A&A

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Context. We study the evolution of a small-scale emerging flux region (EFR) in the quiet Sun, from its emergence in the photosphere to its appearance in the corona and its decay. Aims. We track processes and phenomena that take place across all atmospheric layers; we explore their interrelations and compare our findings with those from recent numerical modelling studies. Methods. We used imaging as well as spectral and spectropolarimetric observations from a suite of space-borne and ground-based instruments.Results. The EFR appears in the quiet Sun next to the chromospheric network and shows all morphological characteristics predicted by numerical simulations. The total magnetic flux of the region exhibits distinct evolutionary phases, namely an initial subtle increase, a fast increase with a cotemporal fast expansion of the region area, a more gradual increase, and a slow decay. During the initial stages, fine-scale G-band and Ca ii H bright points coalesce, forming clusters of positive-and negative-polarity in a largely bipolar configuration. During the fast expansion, flux tubes make their way to the chromosphere, pushing aside the ambient magnetic field and producing pressure-driven absorption fronts that are visible as blueshifted chromospheric features. The connectivity of the quiet-Sun network gradually changes and part of the existing network forms new connections with the newly emerged bipole. A few minutes after the bipole has reached its maximum magnetic flux, the bipole brightens in soft X-rays forming a coronal bright point. The coronal emission exhibits episodic brightenings on top of a long smooth increase. These coronal brightenings are also associated with surge-like chromospheric features visible in Hα, which can be attributed to reconnection with adjacent small-scale magnetic fields and the ambient quiet-Sun magnetic field. Conclusions. The emergence of magnetic flux even at the smallest scales can be the driver of a series of energetic phenomena visible at various atmospheric heights and temperature regimes. Multi-wavelength observations reveal a wealth of mechanisms which produce diverse observable effects during the different evolutionary stages of these small-scale structures.

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Temporal evolution of arch filaments as seen in He I 10 830 Å

Cited by 14 publications

References 55 publications

Three-dimensional magnetic field structure of a flux-emerging region in the solar atmosphere

Three-dimensional magnetic field structure of a flux-emerging region in the solar atmosphere

Tracking Downflows from the Chromosphere to the Photosphere in a Solar Arch Filament System

Emergence of small-scale magnetic flux in the quiet Sun

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Temporal evolution of arch filaments as seen in He I 10 830 Å

Cited by 14 publications

References 55 publications

Three-dimensional magnetic field structure of a flux-emerging region in the solar atmosphere

Three-dimensional magnetic field structure of a flux-emerging region in the solar atmosphere

Tracking Downflows from the Chromosphere to the Photosphere in a Solar Arch Filament System

Emergence of small-scale magnetic flux in the quiet Sun

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Product

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Temporal evolution of arch filaments as seen in He I 10 830 Å