Related papers: UV spectra, bombs, and the solar atmosphere
The term "ultraviolet (UV) burst" is introduced to describe small, intense, transient brightenings in ultraviolet images of solar active regions. We inventorize their properties and provide a definition based on image sequences in…
On 2016 September 20, the Interface Region Imaging Spectrograph observed an active region during its earliest emerging phase for almost 7 hours. The Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory observed…
The emergence of magnetic flux into the solar atmosphere produces, among other phenomena, Ellerman bombs (EBs), which are observed in H alpha and are due to magnetic reconnection in the photosphere below the chromospheric canopy. Signs of…
We propose a model where a supernova explodes in some vicinity of our solar system (some tens of parsecs) in the recent past (some tens of thousands years) with the energy release in cosmic rays of order of $ 10 ^ {51} $ erg. The flux from…
Ellerman bombs (EBs) are small-scale intense brightenings in H$\alpha$ wing images, which are generally believed to be signatures of magnetic reconnection events around the temperature minimum region of the solar atmosphere. They have a…
Umbral flashes (UFs) are emissions in the core of chromospheric lines caused by upward propagating waves steepening into shocks. UFs are followed by an expanding blue shifted umbral wave (UW) and red-shifted plasma returning to the initial…
Intensity bursts in ultraviolet (UV) to X-ray wavelengths and plasma jets are typical signatures of magnetic reconnection and the associated impulsive heating of the solar atmospheric plasma. To gain new insights into the process,…
Explosive transient events occur throughout the solar atmosphere. The differing manifestations range from coronal mass ejections to Ellerman bombs. The former may have negligible signatures in the lower atmosphere, and the latter may have…
Ellerman bombs (EBs) and UV bursts are both brightenings related to flux emergence regions and specifically to magnetic flux of opposite polarity that meet in the photosphere. These two reconnection-related phenomena, nominally formed far…
Small reconnection events in the lower solar atmosphere can lead to its heating, but whether such heating can propagate into higher atmospheric layers and potentially contribute to coronal heating is an open question. We carry out a large…
This work reports a peculiar and interesting train of microwave type III pair bursts in the impulsive rising phase of a solar flare on 2011 September 26. The observations include radio spectrometers at frequency of 0.80 - 2.00 GHz, hard…
We have used the Deep Survey telescope of EUVE to investigate shadows in the diffuse EUV/Soft X-Ray background cast by clouds in the interstellar medium. We confirm the existence of a shadow previously reported, and provide evidence for two…
We simulate several magnetic reconnection processes in the low solar chromosphere/photosphere, the radiation cooling, heat conduction and ambipolar diffusion are all included. Our numerical results indicate that both the high temperature($…
Off-limb observations of the solar corona after Coronal Mass Ejections (CMEs) often show strong, compact, and persistent UV sources behind the eruption. They are primarily observed by the SOHO/UVCS instrument in the "hot" Fe XVIII…
Wide-field EUV telescopes imaging in spectral bands sensitive to 1 MK plasma on the Sun often observe extended ray-like coronal structures stretching radially from active regions to distances of 1.5-2Rsun, which represent the EUV…
Emission from the photosphere in gamma-ray burst (GRB) jets can be substantially affected by subphotospheric energy dissipation, which is typically caused by radiation-mediated shocks (RMSs). We study the observational characteristics of…
During non-flaring times, the radio flux of the Sun at the wavelength of a few centimeters to several tens of centimeters mostly originates from the thermal bremsstrahlung emission, very similar to the EUV radiation. Owing to such a…
Solar flare accelerated electron beams propagating away from the Sun can interact with the turbulent interplanetary media, producing plasma waves and type III radio emission. These electron beams are detected near the Earth with a double…
X-Ray and Ultraviolet (UV) observations of the outer solar atmosphere have been used for many decades to measure the fundamental parameters of the solar plasma. This review focuses on the optically thin emission from the solar atmosphere,…
Absorbtion of Alfven waves is considered to be the main mechanism of heating in the solar corona. It is concluded that the sharp increase of the plasma temperature by two orders of magnitude is related to a self-induced opacity with respect…