Related papers: Reversal-free CaIIH profiles: a challenge for sola…
This review is split into two parts: one on chromospheric line formation in answer to the frequent question "where is my line formed", and one presenting state-of-the-art imagery of the chromosphere. In the first part I specifically treat…
High resolution spectral observations of transition region spectral lines capture the signatures of energy deposition and redistribution at the boundary between the lower and upper atmosphere, and have significant relevance for…
To study the structure of spatially unresolved features of the solar photosphere, we calculated the Stokes profiles of seven photospheric iron lines using two-dimensional nonstationary MHD models of solar granulation for various amounts of…
The presence of the magnetic field is critical to transport energy through the solar atmosphere. The new generation of telescopes will provide new insight into how the magnetic field arrives into the chromosphere and its role in the energy…
(Abridged) We present the results of an X-ray analysis of 80 galaxy clusters selected in the 2500 deg^2 South Pole Telescope survey and observed with the Chandra X-ray Observatory. We divide the full sample into subsamples of ~20 clusters…
Context. Observationally constraining the atmospheric temperature-pressure (TP) profile of exoplanets is an important step forward for improving planetary atmosphere models, further enabling one to place the detection of spectral features…
Low-lying loops have been discovered at the solar limb in transition region temperatures by the Interface Region Imaging Spectrograph (IRIS). They do not appear to reach coronal temperatures, and it has been suggested that they are the…
The strongly coupled hydrodynamic, magnetic, and radiation properties of the plasma in the solar chromosphere makes it a region of the Sun's atmosphere that is poorly understood. We use data obtained with the high-resolution Visible…
Although the magnetic fields in the quiet Sun account for the majority of the magnetic energy in the solar photosphere, inferring their exact spatial distribution, origin, and evolution poses an important challenge because the signals lie…
\textbf{Purpose:} This paper addresses long-standing solar physics problems, namely, the heating of the solar chromosphere and the origin of the solar wind. Our aim is to reveal the related mechanisms behind chromospheric heating and plasma…
Coronal holes are large-scale structures in the solar atmosphere that feature a reduced temperature and density in comparison to the surrounding quiet Sun and are usually associated with open magnetic fields. We perform a differential…
This analysis begins to explore the complex chromosphere-corona mass cycle using a blend of imaging and spectroscopic diagnostics. Single Gaussian fits to hot emission line profiles (formed above 1MK) at the base of coronal loop structures…
Observations of dark cloud cores have been carried out in the mid-infrared using ISOCAM and in the far-infrared using ISOPHOT, both aboard the Infrared Space Observatory. The cores are in most cases detected in emission at 200 and 170…
For many years various asymmetrical profiles of different spectral lines emitted from solar flares have been frequently observed. These asymmetries or line shifts are caused predominantly by vertical mass motions in flaring layers and they…
Is the solar chromosphere always hot, with relatively small temperature variations ($\delta T/T\sim0.1$); or is it cold most of the time, with temperature fluctuations that reach $\delta T/T\sim 10$ at the top of the chromosphere? Or,…
We have mapped the C I 3P1-3P0 line at 492 GHzin three molecular clouds immersed in weak ultraviolet radiation fields, TMC-1, L134N, and IC 5146. In all three clouds, the CI peak TA* ~ 1 K, with very small dispersion. The spatial C I…
We develop a three-dimensional kinetic model of the solar transition region and corona in which the plasma above the chromosphere is collisionless and embedded in a uniform magnetic field. Heating occurs intermittently at discrete locations…
Previously-unexplored diagnostics of O IV in the extreme ultraviolet region 260-280 A are used to derive a temperature and density for a solar flare kernel observed on 2012 March 9 with the Extreme ultraviolet Imaging Spectrometer on the…
The low frequency variability of the extratropical atmosphere involves hemispheric-scale recurring, often persistent, states known as teleconnection patterns or regimes, which can have profound impact on predictability on intra-seasonal and…
The ionization of hydrogen in the solar chromosphere and transition region does not obey LTE or instantaneous statistical equilibrium because the timescale is long compared with important hydrodynamical timescales, especially of…