相关论文: A New Calculation of Ne IX Line Diagnostics
The R ratio is a useful diagnostic of the X-ray emitting astrophysical plasmas defined as the intensity ratio of the forbidden over the inter-combination lines in the K$\alpha$ line complex of He-like ions. The value is altered by…
This paper continues our study of the behaviour of near infrared helium recombination lines in planetary nebula. We find that the 1.7007um 4^3D-3^3P HeI line is a good measure of the HeI recombination rate, since it varies smoothly with the…
The so called "isobar run" or RHIC was designed to compare a number of observables for collisions of $^{96}_{40}Zr$ with those of $^{96}_{44}Ru$, aimed at identification of $Z$-dependent effects. However, as the STAR data have shown with…
A detailed analysis of the radiative and Auger de-excitation channels of K-shell vacancy states in Fe II-Fe IX has been carried out. Level energies, wavelengths, A-values, Auger rates and fluorescence yields have been calculated for the…
Recent observation and analysis of kilonovae (KNe) spectra as a result of neutron star mergers require accurate and complete atomic structure and collisional data for interpretation. Ideally, the atomic datasets for elements predicted to be…
We compare calculated intensities of lines of CII, NI, NII, OI and OII with a published deep spectroscopic survey of planetary nebula IC 418. Our calculations use a self-consistent nebular model and a synthetic spectrum of the central star…
We present Maxwellian-averaged effective collision strengths for the electron-impact excitation of S III over a wide range of electron temperatures of astrophysical importance, log T(K) = 3.0-6.0. The calculation incorporates 53…
Radiative accelerations on Ne are calculated for the atmospheres of main sequence stars with 11000 < Teff < 15000 K, corresponding to the range of the HgMn stars. The calculations take into account neon fine structure as well as shadowing…
We report on comprehensive laboratory studies of the K-shell dielectronic recombination (DR) resonances of Fe XXV - XXI ions that prominently contribute to the hard X-ray spectrum of hot astrophysical plasmas. By scanning a monoenergetic…
From ISO [Ne V] 14.3/24.3 micron line flux ratios, we find that 10 out of 20 planetary nebulae (PNs) have measured ratios below the low-electron density (N_e) theoretical predicted limit. Such astronomical data serve to provide important…
Ammonia is one of the most widely observed molecules in space, and many observations are able to resolve the hyperfine structure due to the electric quadrupole moment of the nitrogen nucleus. The observed spectra often display anomalies in…
Four Fe IX transitions in the wavelength range 188--198 A are identified for the first time in spectra from the EUV Imaging Spectrometer on board the Hinode satellite. In particular the emission line at 197.86 A is unblended and close to…
We present in this paper new and updated calculations of the ionization equilibrium for all the elements from H to Ni. We collected for these elements all the data available in the literature for the ionization and radiative plus…
The calculation of accurate collision strengths for atomic transitions has been a long standing problem in quantitative spectroscopy. Most modern calculations are based on the R-matrix method and problems pertaining to the use of this…
Theoretically self-consistent calculations for photoionization and (e + ion) recombination are described. An identical eigenfunction expansion for the ion is employed in coupled channel calculations for both processes, thus ensuring…
The primary X-ray diagnostic lines in He-like ions are mainly excited by electron impact from the ground level to the n = 2 levels, but at high temperatures n > 2 levels are also excited. In order to describe the atomic processes more…
Nuclear halos are very exotic quantal structures observed far from stability. Because of their short lifetime, they are mostly studied through reactions. The ratio method offers a new observable: the ratio of angular differential cross…
Theoretical reaction rates in the temperature range 0.01*10^9<=T[K]<=10.*10^9 are calculated in the statistical model (Hauser-Feshbach formalism) for targets with 10<=Z<=83 (Ne to Bi) and for a mass range reaching the neutron and proton…
We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in He-like Kr XXXV. The GRASP (general-purpose relativistic atomic structure package) is adopted for…
Relativistically broadened and redshifted 6.4 -- 6.9 keV iron K lines are observed from many accretion powered objects, including X-ray binaries and active galactic nuclei (AGN). Existence of gas close to the central engine implies large…