Related papers: Self-absorption in the solar transition region
Multi-wavelength ultraviolet (UV) observations by the IRIS satellite in active region NOAA 12529 have recently pointed out the presence of long-lasting brightenings, akin to UV bursts, and simultaneous plasma ejections occurring in the…
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…
The solar transition region satisfies the conditions for presence of non-Maxwellian electron energy distributions with high-energy tails at energies corresponding to the ionization potentials of many ions emitting in the EUV and UV portions…
Transition-region loops are a type of critical magnetic structure in the solar atmosphere, yet their physical properties and evolutionary characteristics remain statistically poorly constrained. We aim to statistically characterize the…
Ellerman Bombs are signatures of magnetic reconnection, which is an important physical process in the solar atmosphere. How and where they occur is a subject of debate. In this paper we analyse Sunrise/IMaX data together with 3D MHD…
Surges often appear as a result of the emergence of magnetized plasma from the solar interior. Traditionally, they are observed in chromospheric lines such as H$\alpha$ 6563 \AA and Ca II 8542 \AA. However, whether there is a response to…
Transition region explosive events are characterized by non-Gaussian profiles of the emission lines formed at transition region temperatures, and they are believed to be manifestations of small-scale reconnection events in the transition…
We investigate various dynamic processes including magnetic reconnection, chromospheric evaporation, and coronal rain draining in two limb solar flares through imaging and spectroscopic observations from the Interface Region Imaging…
A triplet of subordinate lines of Mg II exists in the region around the h&k lines. In solar spectra these lines are seen mostly in absorption, but in some cases can become emission lines. The aim of this work is to study the formation of…
When an AGN is obscured, the warm reflecting gas nearby can be seen by a combination of bremsstrahlung, intrinsic line emission, and reflection of the nuclear continuum, both by electron scattering and by resonance line scattering.…
Recent observations from the Interface Region Imaging Spectrograph (IRIS) appear to show impulsive brightenings in high temperature lines, which when combined with simultaneous ground based observations in H$\alpha$, appear co-spatial to…
The Interface Region Imaging Spectrograph (IRIS) reveals numerous small-scale (sub-arcsecond) brightenings that appear as bright dots sparkling the solar transition region in active regions. Here, we report a statistical study on these…
The solar transition region (TR), in which above the photosphere the tempera- ture increases rapidly and the density drops dramatically, is believed to play an important role in coronal heating and solar wind acceleration. Long-lasting…
Recent high-cadence flare campaigns by the Interface Region Imaging Spectrograph (IRIS) have offered new opportunities to study rapid processes characteristic of flare energy release, transport, and deposition. Here, we examine high-cadence…
The high temporal, spatial and spectral resolution of Interface Region Imaging Spectrograph (IRIS) has provided new insights into the understanding of different small-scale processes occurring at the chromospheric and transition region (TR)…
Since their discovery twenty year ago, transition region bright points (TRBPs) have never been observed spectroscopically. Bright point properties have not been compared with similar transition region and coronal structures. In this work we…
This study analyzed the Doppler shift in the solar spectrum using the Interface Region Imaging Spectrograph (IRIS). Two types of oscillations were investigated: long period damp and short period damp. The researchers observed periodic…
While previous work explored the fractality and self-organized criticality (SOC) of flares and nanoflares in wavelengths emitted in the solar corona (such as in hard X-rays, soft X-rays, and EUV wavelenghts), we focus here on impulsive…
A three-dimensional picture of the solar atmosphere's thermodynamics can be obtained by jointly analyzing multiple spectral lines that span many formation heights. In paper I, we found strong correlations between spectral shapes from a…
Magnetic reconnection is the key mechanism for energy release in solar eruptions, where the high-temperature emission is the primary diagnostic for investigating the plasma properties during the reconnection process. Non-thermal broadening…