相关论文: Hyperfine Splitting in the VALD Database of Spectr…

The core of planetary nebula NGC 6302 is filled with high-excitation photoionised gas at low expansion velocities. It represents a unique astrophysical situation in which to search for hyperfine structure (HFS) in coronal emission lines…

We used the moderately high spectral resolution of FLAMES/GIRAFFE (R=10000) to derive electron densities from [OII] line ratios in 6 galaxies at z~0.55. These measurements have been done through the GIRAFFE multiple integral field units and…

Archived high-resolution X-ray spectra in the 13~\AA\ to 22~\AA\ range from the Flat Crystal Spectrometer (FCS), an instrument on the Solar Maximum Mission operating in the 1980s, are analyzed with reference to nonflaring active regions,…

We present a catalogue of 430 Field Horizontal Branch (FHB) stars, selected from the Hamburg/ESO Survey (HES), which fortuitously align with high column density neutral hydrogen (HI) High-Velocity Cloud (HVC) gas. These stars are ideal…

Aims: We generate theoretical ultraviolet and extreme-ultraviolet emission line ratios for O IV and show their strong versatility as electron temperature and density diagnostics for astrophysical plasmas. Methods: Recent fully relativistic…

X-ray absorption spectroscopy (XAS) is a premier technique for materials characterization, providing key information about the local chemical environment of the absorber atom. In this work, we develop a database of sulfur K-edge XAS spectra…

Variable stars play a very important role in our understanding of the Milky Way and the universe. In recent years, many survey projects have generated a large amount of photometric data, necessitating classifiers that can quickly identify…

In recent years, automatic classifiers of image cutouts (also called "stamps") have shown to be key for fast supernova discovery. The Vera C. Rubin Observatory will distribute about ten million alerts with their respective stamps each…

PolarBase is an evolving data base that contains all stellar data collected with the ESPaDOnS and NARVAL high-resolution spectropolarimeters, in their reduced form, as soon as they become public. As of early 2014, observations of 2,000…

\textquotedblleft Stark" broadening theories and calculations have been extensively developed for about 50 years and can now be applied to many needs, especially for accurate spectroscopic diagnostics and modeling. This requires the…

We present a wide-area and deep optical identification catalog for radio sources based on the VLASS Epoch 2 catalog at 3 GHz. Optical counterparts are identified using the final-year internal processing of the Hyper Suprime-Cam Subaru…

Radiative transfer calculations have predicted intensity enhancements for optically thick emission lines, as opposed to the normal intensity reductions, for astrophysical plasmas under certain conditions. In particular, the results are…

The ground state hyperfine splitting of positronium, $\Delta_{\mathrm{HFS}}$, is sensitive to high order corrections of QED. A new calculation up to $\mathrm{O}(\alpha ^3 \ln \alpha)$ has revealed a $3.9\sigma$ discrepancy between the QED…

The ground state hyperfine splitting of positronium $\Delta_{\mathrm{HFS}}$ is sensitive to high order corrections of quantum electrodynamics (QED) in bound state. The theoretical prediction and the averaged experimental value for…

We conducted research on the classification and physical properties of 10 objects from the HASH (Hong Kong/Australian Astronomical Observatory/Strasbourg Observatory H-alpha Planetary Nebula (PN)) database with small angular sizes (<…

We have calculated X-ray and UV spectra of Be-like Fe (FeXXIII) ion in collisional-radiative model including all fine-structure transitions among the 2s^2, 2s2p, 2p^2, 2snl, and 2pnl levels where n=3 and 4, adopting data for the collision…

Several models of level densities exist and they often make simplified assumptions regarding the overall behavior of the total level densities (LD) and the intrinsic spin and parity distributions of the excited states. Normally, such LD…

We present measurements of the hyperfine structure splittings of $nS_{1/2}$ Rydberg states of $^{85}$Rb for $n$= 43, 44, 45 and 46. From the splittings, the hyperfine coupling constant, $A_{\mathrm{HFS}}$, is determined to be 15.372(80)…

The study of Stark broadening of neutral helium lines, despite significant advances over recent decades, has not led to updated large grids of helium line profiles relevant to the spectroscopic study of helium-rich stars. While the…

The calculation of line widths constitutes theoretical and computational challenges in the calculation of opacities of hot dense plasmas. Opacity models use line broadening approximations that are untested at stellar interior conditions.…