The solar chromosphere at high resolution with IBIS

Cauzzi, G.; Reardon, K.; Rutten, R. J.; Tritschler, A.; Uitenbroek, H.

doi:10.1051/0004-6361/200811595

Cited by 94 publications

(114 citation statements)

References 44 publications

Supporting

Mentioning

104

Contrasting

Order By: Relevance

“…Without micro-turbulence, the full width at half maximum (FWHM) of the chromospheric core, measured in our spatially resolved spectra is about 180 mÅ. Corresponding measurements from quiet-Sun line profiles were carried out by Cauzzi et al (2009), who found values in the range 450−550 mÅ. This means that our profiles are of the order of a factor 2.5 narrower than observed, assuming that instrumental degradation has a negligible effect on the FWHM of the profiles.…”

Section: Radiative Transfersupporting

confidence: 52%

Non-local thermodynamic equilibrium inversions from a 3D magnetohydrodynamic chromospheric model

Rodríguez

Socas‐Navarro

Carlsson

et al. 2012

A&A

View full text Add to dashboard Cite

Context. The structure of the solar chromosphere is believed to be governed by magnetic fields, even in quiet-Sun regions that have a relatively weak photospheric field. During the past decade inversion methods have emerged as powerful tools for analyzing the chromosphere of active regions. The applicability of inversions to infer the stratification of the physical conditions in a dynamic 3D solar chromosphere has not yet been studied in detail. Aims. This study aims to establish the diagnostic capabilities of non-local thermodynamical equilibrium (NLTE) inversion techniques of Stokes profiles induced by the Zeeman effect in the Ca ii λ8542 Å line. Methods. We computed the Ca ii atomic level populations in a snapshot from a 3D radiation-MHD simulation of the quiet solar atmosphere in non-LTE using the 3D radiative transfer code Multi3d. These populations were used to compute synthetic full-Stokes profiles in the Ca ii λ8542 Å line using 1.5D radiative transfer and the inversion code Nicole. The profiles were then spectrally degraded to account for finite filter width, and Gaussian noise was added to account for finite photon flux. These profiles were inverted using Nicole and the results were compared with the original model atmosphere. Results. Our NLTE inversions applied to quiet-Sun synthetic observations provide reasonably good estimates of the chromospheric magnetic field, line-of-sight velocities and somewhat less accurate, but still very useful, estimates of the temperature. Threedimensional scattering of photons cause cool pockets in the chromosphere to be invisible in the line profile and consequently they are also not recovered by the inversions. To successfully detect Stokes linear polarization in this quiet snapshot, a noise level below 10 −3.5 is necessary.

show abstract

Section: Radiative Transfersupporting

confidence: 52%

Non-local thermodynamic equilibrium inversions from a 3D magnetohydrodynamic chromospheric model

Rodríguez

Socas‐Navarro

Carlsson

et al. 2012

A&A

View full text Add to dashboard Cite

show abstract

“…As a result, we found that the velocity changes with wavelength in Ca II 8542 Å but this is not the case in Hα. This is because the Hα line is formed either in chromospheric fibrils or in the deep photosphere whereas the Ca II 8542 Å line samples the layer between them (Cauzzi et al , 2009. We speculate that the velocity changes with wavelength seen in Ca II 8542 Å may reflect an intrinsic property of the vertical flows above the pores/SMCs in the lower chromosphere.…”

Section: Vertical Motion In the Lower Chromospherementioning

confidence: 89%

“…Both lines showed fibrils with bright feet. Generally, darker Hα fibrils correspond to higher density, and Ca II brightness is more related to temperature (Cauzzi et al, 2009). Figure 3 shows the observation by Hinode/SOT for the ROI which is marked with a small box in Figure 1(a).…”

Section: Observation and Analysismentioning

confidence: 99%

“…The Hα line is formed either in chromospheric fibrils or in deep photosphere whereas the Ca II 8542 Å line samples the layers in between the fibrils and the photosphere (Cauzzi et al , 2009. Leenaarts et al (2006) reported that the intensity in the far wings of the Ca II 8542 Å line is highly sensitive to the presence of magnetic structures.…”

Section: Vertical Motion In the Lower Chromospherementioning

confidence: 99%

“…Since the intensity level in the line spectra reflects the formation height as shown in Figure 2 (Cauzzi et al , 2009), the bisectors measured from the wings of the line represent the Doppler shift at a lower altitude of the atmosphere. In this study, we considered the wavelength ranges of λ = 1.0 -2.5 Å in Ca II 8542 Å, and λ = 1.9 Å and λ = 0.5 -1.2 Å in Hα, respectively.…”

Section: Vertical Motion In the Lower Chromospherementioning

confidence: 99%

See 2 more Smart Citations

FISS Observations of Vertical Motion of Plasma in Tiny Pores

et al. 2013

View full text Add to dashboard Cite

Pores can be exploited for the understanding of the interaction between smallscale vertical magnetic field and the surrounding convective motions as well as the transport of mechanical energy into the chromosphere along the magnetic field. For better understanding of the physics of pores, we investigate tiny pores in a new emerging active region (AR11117) that were observed and the Ca II 8542 Å line simultaneously taken by the FISS. The coordinated observation reveals that the pores are filled with plasma which moves down slowly and are surrounded by stronger downflow in the photosphere. In the lower chromosphere, we found that the plasma flows upwards inside the pores while the plasma in the SMCs is always moving down. Our inspection of the Ca II 8542 Å line from the wing to the core shows that the upflow in the pores slows down with height and turns into downflow in the upper chromosphere while the downflow in the SMCs gains its speed. Our results are in agreement with the numerical studies which suggest that rapid cooling of the interior of the pores drives a strong downflow, which collides with the dense lower layer below and rebounds into an upflow.

show abstract

Cloud modeling of a network region in Hα

Bostancı

2011

Astron Nachr

View full text Add to dashboard Cite

In this paper, we analyze the physical properties of dark mottles in the chromospheric network using two-dimensional spectroscopic observations in Hα obtained with the Göttingen Fabry-Perot Spectrometer in the Vacuum Tower Telescope at the Observatory del Teide, Tenerife. Cloud modeling was applied to measure the mottles' optical thickness, source function, Doppler width, and line-of-sight velocity. Using these measurements, the number density of hydrogen atoms in levels 1 and 2, total particle density, electron density, temperature, gas pressure, and mass density parameters were determined with the method of Tsiropoula & Schmieder (1997). We also analyzed the temporal behaviour of a mottle using cloud parameters. Our result shows that it is dominated by 3 minute signals in source function, and 5 minutes or more in velocity.

show abstract

The solar chromosphere at high resolution with IBIS

Cited by 94 publications

References 44 publications

Non-local thermodynamic equilibrium inversions from a 3D magnetohydrodynamic chromospheric model

Non-local thermodynamic equilibrium inversions from a 3D magnetohydrodynamic chromospheric model

FISS Observations of Vertical Motion of Plasma in Tiny Pores

Cloud modeling of a network region in Hα

Contact Info

Product

Resources

About