Related papers: UV spectra, bombs, and the solar atmosphere
Solar observations with the Atacama Large Millimeter/submillimeter Array (ALMA) provide us with direct measurements of the brightness temperature in the solar chromosphere. We study the temperature distributions obtained with ALMA Band 6…
Internal shocks provide a plausible heating mechanism in the jets of gamma-ray bursts (GRBs). Shocks occurring below the jet photosphere are mediated by radiation. It was previously found that radiation mediated shocks (RMSs) inside GRB…
Solar macrospicules are beam-like cool plasma ejections of size in-between spicules and coronal jets, which can elucidate potential connections between plasma jetting activity at different scales. With high-resolution observations from the…
We explore the origin of the observed Lya and other UV lines from galaxies at z<3.7 by detailed modelling of the spectra. The objects are chosen among those showing a) UV-optical-near-IR lines, b) only UV lines and c) those showing Lya in…
(Abridged) The propagation of ionizing radiation through model atmospheres of terrestrial-like exoplanets is studied for a large range of column densities and incident photon energies using a Monte Carlo code we have developed to treat…
The first light that escapes from a supernova explosion is the shock breakout emission, which produces a bright flash of UV or X-ray radiation. Standard theory predicts that the shock breakout spectrum will be a blackbody if the gas and…
Using new ultraviolet (UV) spectra of five background quasars from the Cosmic Origins Spectrograph on the Hubble Space Telescope, we analyze the low-latitude (|b|=20-30 degree) regions of the Fermi Bubbles, the giant gamma-ray emitting…
Radiation-mediated shocks (RMSs) occurring below the photosphere in a gamma-ray burst (GRB) jet could play a crucial role in shaping the prompt emission. In this paper, we study the time-resolved signal expected from such early shocks. We…
A joint campaign of several space-borne and ground-based observatories, such as the GREGOR solar telescope, the Extreme-ultraviolet Imaging Spectrometer (EIS), and the Interface Region Imaging Spectrograph (Hinode Observing Plan 381, 11-22…
Ellerman bombs (EBs) with significant H$\alpha$ wing emissions and ultraviolet bursts (UV bursts) with strong Si IV emissions are two kinds of small transient brightening events that occur in the low solar atmosphere.We numerically…
Beamed gamma-ray burst (GRB) sources produce a bow shock in their gaseous environment. The emitted flux from this bow shock may dominate over the direct emission from the jet for lines of sight which are outside the angular radius of the…
Type-II radio bursts are typically observed below ~ 400 MHz, with narrow-band slowly-drifting fundamental and harmonic structures. Here we report an unusual high-frequency wide-band type-II burst with starting frequency as high as 600 - 700…
Recent observations have successfully detected UV or infrared flux from galaxies at the epoch of reionization. However, the origin of their radiative properties has not been fully understood yet. Combining cosmological hydrodynamic…
Recent high-resolution and high-cadence EUV imaging has revealed a new phenomenon, impacting prominence debris, where prominence material from failed or partial eruptions can impact the lower atmosphere, releasing energy. We report a clear…
Solar ultraviolet (UV) bursts are small-scale compact brightenings in transition region images. The spectral profiles of transition region lines in these bursts are significantly enhanced and broadened, often with chromospheric absorption…
Turbulent plasma motion is common in the universe, and invoked in solar flares to drive effective acceleration leading to high energy electrons. Unresolved mass motions are frequently detected in flares from extreme ultraviolet (EUV)…
Popular scientific summary -- The atmosphere of the Sun is envisioned as composed of inherently complex, non-homogeneous, and dynamic layers. A detailed understanding of the physical processes involved in these layers is still lacking. For…
On the Sun,jets in light bridges are frequently observed with high-resolution instruments.The respective roles played by convection and the magnetic field in triggering such jets are not yet clear.We report a small fan-shaped jet along a LB…
Venus exhibits strong and changing contrasts at ultraviolet wavelengths apparently related to the clouds and the dynamics in the cloud layer, but to date their origin continues to be unknown. We investigate the nature of the UV contrasts…
The Alfv\'{e}n speed and plasma beta in photospheric bright points observed by the Broadband Filter Imager (BFI) of the Solar Optical Telescope (SOT) on board the \textit{Hinode} satellite, are estimated seismologically. The diagnostics is…