Search Publications
Flows in active region loops observed by Hinode EIS
Del Zanna, G.
We aim to investigate the overall characteristics of coronal active region loops and their evolution. The Hinode database was searched for observations of active regions as they crossed the Sun centre. NOAA 10926 was selected. The morphology of this young active region did not significantly change over the course of a few days. Persistent redshift…
Hinode observations of transverse waves with flows in coronal loops
Wang, T. J.; Ofman, L.
Aims: We report the first evidence for transverse waves in coronal multithreaded loops with cool plasma ejected from the chromosphere flowing along the threads. These observations are good candidates for coronal seismology.
Methods: We analyzed observations made with Solar Optical Telescope (SOT) on board the Hinode satellite in the Ca II H li…
Hinode XRT observations of a long-lasting coronal sigmoid
Canfield, R. C.; McKenzie, D. E.
Aims:Coronal sigmoids are important sources of eruptions into interplanetary space, and a handful of models have been proposed to explain their characteristic S shape. However, the coronal X-ray images available to date have generally not had sufficient resolution to distinguish between these models. The goal of the present investigation is to det…
SOHO/SUMER observations of prominence oscillation before eruption
Solanki, S. K.; Innes, D. E.; Chen, P. F.
Context: Coronal mass ejections (CMEs), as a large-scale eruptive phenomenon, often reveal some precursors in the initiation phase, e.g., X-ray brightening, filament darkening, etc., which are useful for CME modelling and space weather forecasting.
Aims: With the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectroscopic observa…
Multi-wavelength spatially resolved analysis of quasi-periodic pulsations in a solar flare
Melnikov, V. F.; Nakariakov, V. M.; Inglis, A. R.
Aims: We aim to perform a spatially resolved analysis of a quasi-periodic pulsation event from 8th May 1998 using microwave data from the Nobeyama Radioheliograph and Radiopolarimeter, and X-ray data from the Yohkoh satellite.
Methods: Time spectra of the signals integrated over the emission source are constructed with the use of the Lomb-Scar…
Open magnetic flux tubes in the corona and the transport of solar energetic particles
Krucker, S.; Klein, K. -L.; Lointier, G. +1 more
We investigate how magnetic fields guide energetic particles through the corona into interplanetary space and eventually to a spacecraft near the Earth. A set of seven simple particle events is studied, where energetic electrons (30-500 keV; Wind spacecraft) or protons (5-55 MeV; SoHO) were released together with low-energy electron beams producin…
Sensitivity of helioseismic gravity modes to the dynamics of the solar core
Eff-Darwich, A.; García, R. A.; Mathur, S. +1 more
Context: The dynamics of the solar core cannot be properly constrained through the analysis of acoustic oscillation modes. Gravity modes (g modes) are necessary to understand the structure and dynamics of the deepest layers of the Sun. Through recent progress on the observation of these modes - both individually and collectively - new information …
On Lyman-line asymmetries in quiescent prominences
Heinzel, P.; Anzer, U.; Schmieder, B. +1 more
Aims: We study the asymmetries of the synthetic hydrogen Lyman lines and the process responsible for their formation.
Methods: To obtain the synthetic Lyman line profiles, we use a multi-thread prominence fine-structure model consisting of identical 2D threads. The 2D thread models are in MHS equilibrium, include an empirical prominence-corona…
The relationship between EUV dimming and coronal mass ejections. I. Statistical study and probability model
Harrison, R. A.; Brown, D. S.; Bewsher, D.
Aims:There have been many studies of extreme-ultraviolet (EUV) dimming in association with coronal mass ejection (CME) onsets. However, there has never been a thorough statistical study of this association, covering appropriate temperature ranges. Thus, we make use of a large campaign database utilising the Coronal Diagnostic Spectrometer (CDS) an…
Spectral irradiance variations: comparison between observations and the SATIRE model on solar rotation time scales
Solanki, S. K.; Krivova, N. A.; Kopp, G. +2 more
Aims: We test the reliability of the observed and calculated spectral irradiance variations between 200 and 1600 nm over a time span of three solar rotations in 2004.
Methods: We compare our model calculations to spectral irradiance observations taken with SORCE/SIM, SoHO/VIRGO, and UARS/SUSIM. The calculations assume LTE and are based on the …