Related papers: Observations and NLTE modeling of Ellerman bombs
Here we present the study of a compact emission source during an X1.3 flare on 2022-March-30. Within a $\sim41$~s period (17:34:48 UT to 17:35:29 UT), IRIS observations show spectral lines of Mg II, C II and Si IV with extremely broadened,…
The observation of eclipses during X-rays flares taking place in active cool stars binaries allows us to calculate the position and size of the flares. This information cannot be derived by analyzing the decay of the flares, a frequently…
A spectrum of a hot spot, produced by radiation of accretion shock at T Tauri star's surface, has been calculated taking into account non-LTE effects for HeI, HeII, CaI and CaII, using LTE-calculations of spot's atmospheric structure,…
A comprehensive model atom was developed for Si I-II-III using the most up-to-date atomic data available so far. Based on the non-local thermodynamic equilibrium (non-LTE = NLTE) line formation for Si I, Si II, and Si III and…
Dust properties are very likely affected by the environment in which dust grains evolve. For instance, some analyses of cold clumps (7 K- 17 K) indicate that the aggregation process is favored in dense environments. However, studying warm…
Cosmological simulations indicate that nearly half of the baryons in the nearby Universe are in the warm-hot intergalactic medium (WHIM) phase, and about a half them reside in cosmic filaments connecting galaxy clusters. Recent…
With the ASTE telescope, we have made observations of three low-mass protostellar envelopes around L483, B335, and L723 in the submillimeter CS ($J$=7--6) and HCN ($J$=4--3) lines. We detected both the CS and HCN lines toward all the…
One of the explanations for the recent EDGES-LOW band 21-cm measurements of a strong absorption signal around 80~MHz is the presence of an excess radio background to the Cosmic Microwave Background (CMB). Such excess can be produced by the…
Weak spectral features in BL Lacertae objects (BL Lac) often provide a unique opportunity to probe the inner region of this rare type of active galactic nucleus. We present a Hubble Space Telescope/Cosmic Origins Spectrograph observation of…
We aim to investigate the temperature enhancements and formation heights of impulsive heating phenomena in solar active-regions such as Ellerman bombs (EBs), ultraviolet bursts (UVBs), and flaring active-region fibrils (FAFs) using…
We present a grid of computed non-local thermodynamic equilibrium (NLTE) equivalent widths (EW) and NLTE abundance corrections for four Ba II lines: 4554, 5853, 6141, and 6496 A. The grid can be useful in deriving the NLTE barium abundance…
We present the results of 450 and 850 micron continuum mapping of the HII region KR 140 using the SCUBA instrument on the JCMT. KR 140 is a small (5.7 pc diameter) HII region at a distance of 2.3+/-0.3 kpc. Five of the six IRAS point…
Exceptional points (EPs) in non-Hermitian systems are branch singularities where eigenvalues and eigenvectors simultaneously coalesce, leading to rich topological phenomena beyond those in Hermitian systems. In this work, we systematically…
A single case study of a CBP in an equatorial coronal hole with an exceptionally large size is investigated to extend our understanding of the formation of mini-filaments, their destabilisation and the origin of the eruption triggering the…
We present a rest-frame ultraviolet analysis of ~120 z~3.1 Lyman Alpha Emitters (LAEs) in the Extended Chandra Deep Field South (ECDF-S). Using Hubble Space Telescope (HST) images taken as part of the Galaxy Evolution From Morphology and…
Wisconsin H-Alpha Mapper (WHAM) observations reveal high-velocity and [NII]$\lambda6584$ emission lines in the same direction and velocity as ultraviolet absorption-line features that have been previously associated with the biconical…
Ultra-hot Jupiters (UHJs) undergo intense irradiation by their host stars and are expected to experience non-local thermodynamic equilibrium (NLTE) effects in their atmospheres. Such effects are computationally intensive to model but, at…
The polarization of light across spectral lines contains information about the circumstellar material on small spatial scales. Many models relate the circumstellar environment to observable polarization changes across spectral lines.…
The narrow line region of active galaxies is formed by gas clouds surrounded by a diluted gas. Standard one-dimensional photoionization models are usually used to model this region in order to reproduce the observed emission lines. Since…
We report on observations of a solar prominence obtained on 26 April 2007 using the Extreme Ultraviolet Imaging Spectrometer on Hinode. Several regions within the prominence are identified for further analysis. Selected profiles for lines…