Related papers: Small-scale, Dynamic Bright Blobs in Solar Filamen…
The hydrogen Lyman lines provide important diagnostic information about the dynamics of the chromosphere, but there have been few systematic studies of their variability during flares. We investigate Doppler shifts in these lines in several…
A photon of wavelength lambda ~1 micron interacting with a dust grain of radius a_p ~ 1 mm (a "pebble") undergoes scattering in the forward direction, largely within a small characteristic diffraction angle theta_s ~ lambda/a_p ~ 100".…
The gamma-ray emission of blazar jets shows a pronounced variability and this feature provides limits to the size and to the speed of the emitting region. We study the gamma-ray variability of bright blazars using data from the first 18…
The properties of Ellerman bombs (EBs), small-scale brightenings in the H-alpha line wings, have proved difficult to establish due to their size being close to the spatial resolution of even the most advanced telescopes. Here, we aim to…
We study a fragment of a large quiescent filament observed on May 29, 2017 by the Interferometric BIdimensional Spectropolarimeter (IBIS) mounted at the Dunn Solar Telescope. We focus on its quiescent stage prior to its eruption. We analyse…
Bright points (BPs) are manifestations of small magnetic elements in the solar photosphere. Their brightness contrast not only gives insight into the thermal state of the photosphere (and chromosphere) in magnetic elements, but also plays…
Strongly intermittent turbulence is observed in the shadow of a limiter in the Large Plasma Device (LAPD) at UCLA [W. Gekelman, H. Pfister, Z. Lucky, J. Bamber, D. Leneman, and J. Maggs, Rev. Sci. Inst. {\bfseries 62}, 2875 (1991)]. The…
The expansion with height of the solar photospheric magnetic field and the plasma flows is investigated for three isolated bright points (BPs). The BPs were observed simultaneously with 3 instruments at the GREGOR telescope: (1) filtergrams…
Aims. The H-alpha emission of solar flare kernels and associated hard X-ray (HXR) emission often show similar time variations but their light curves are shifted in time by energy transfer mechanisms. We searched for fast radiative response…
The continuum intensity at wavelengths around 1 mm provides an excellent way to probe the solar chromosphere. Future high-resolution millimetre arrays, such as the Atacama Large Millimeter Array (ALMA), will thus produce valuable input for…
The most remarkable class of high-redshift objects observed so far is extended Ly$\alpha$ emission-line blobs found in an over-density region at redshift 3.1. They may be either a dust-enshrouded, extreme starburst galaxy with a large-scale…
Solar active regions (ARs) are thought to be formed by magnetic fields from the convection zone. Our flux emergence simulations revealed that a strong horizontal divergent flow (HDF) of unmagnetized plasma appears at the photosphere before…
We combine observations of the Coronal Multi-channel Polarimeter (CoMP) and the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) to study the characteristic properties of (propagating) Alfvenic motions and…
Acoustic waves and pulses propagating from the solar photosphere upwards may quickly develop into shocks due to the rapid decrease of atmospheric density. However, if they propagate along a magnetic flux tube, then the nonlinear steepening…
Solar coronal plumes long seemed to possess a simple geometry supporting spatially coherent, stable outflow without significant fine structure. Recent high-resolution observations have challenged this picture by revealing numerous…
We analyze a sample of bright short bursts from the BATSE 4B-catalog and find that many short bursts are highly variable ($\delta t_{min}/T\ll 1$, where $\delta t_{min}$ is the shortest pulse duration and T is the burst duration). This…
Six cases of fast radio bursts (FRBs) have recently been discovered. The FRBs are bright (~0.1 - 1 Jy) and brief (~ 1 ms) pulses of radio emission with dispersion measures (DMs) that exceed Galactic values, and hence FRBs have been…
We use high spatial and temporal resolution observations from the Swedish Solar Telescope to study the chromospheric velocities of a C-class flare originating from active region NOAA 10969. A time-distance analysis is employed to estimate…
We present the first observations of chromospheric swirls using the Hydrogen-alpha Rapid Dynamics camera and Rapid Oscillations in the Solar Atmosphere imaging instruments at the Dunn Solar Telescope. These vortices contribute to heating…
The deep sea is weakly stratified in density but shows considerable variations in turbulent motions in all three directions. When registered by moored high-resolution temperature 'T'-sensors, the motions cause variations of 0.01degrC or…