Related papers: Improved He I Emissivities in the Case B Approxima…
Modeling environments that are not in local thermal equilibrium, such as protoplanetary disks or planetary atmospheres, with molecular spectroscopic data from space telescopes requires knowledge of the rate coefficients of rovibrationally…
We have measured electron-ion recombination for Fe$^{9+}$ forming Fe$^{8+}$ and for Fe$^{10+}$ forming Fe$^{9+}$ using merged beams at the TSR heavy-ion storage-ring in Heidelberg. The measured merged beams recombination rate coefficients…
Modeling of molecular emission from interstellar clouds requires the calculation of rates for excitation by collisions with the most abundant species. The present paper focuses on the calculation of rate coefficients for rotational…
Using the new version of the photoionization code Titan designed for plane-parallel photoionized thick hot media, which is unprecedented from the point of view of line transfer, we have undertaken a study of the influence of different…
We present quantum mechanical and quasiclassical trajectory calculations of cross sections for rovibrational transitions in ortho- and para-H_2 induced by collisions with He atoms. Cross sections were obtained for kinetic energies between…
This paper describes a new determination of the primordial helium abundance (Y_P), based on the abundance analysis of five metal-poor extragalactic HII regions. For three regions of the sample (SBS 0335-052, I Zw 18, and H29) we present…
Recent experimental progress has substantially improved the available cross-section data for the p-$^{11}$B fusion reaction, particularly in energy regions that previously lacked direct measurements. In this study, we develop a…
It is shown that above the temperature of maximum abundance, recombination rates into the excited states of He-like ions that are calculated using earlier, more approximate methods differ markedly from rates obtained from recent…
The current report presents the work to investigate the recombination lines of CII in the spectra of planetary nebulae. Two CIII targets were prepared and used to generate theoretical data required in the investigation of recombination…
Our previous studies of dissociative recombination, and vibrational excitation/de-excitation of the BeH$^+$ ion, based on the multichannel quantum defect theory, are extended to collision energies above the dissociation threshold, taking…
In a previous article, with a new code designed for a photoionized thick hot medium using a full transfer treatment of both lines and continuum, we have studied the He-like emission of a medium photoionized by an X-ray source. We considered…
The hardness of the ionizing continuum from the first sources of UV radiation plays a crucial role in the reionization of the intergalactic medium (IGM). While usual stellar populations have soft spectra, mini-quasars or metal-free stars…
We present new results obtained from a series of follow-up e+e- coincidence measurements in heavy-ion collisions, utilizing an improved experimental set-up at the double-Orange beta-spectrometer of GSI. The collision system U+Ta was…
Surface recombination affects both light-to-electricity and electricity-to-light conversion in solar cells (SCs). Therefore, quantitative analysis and reduction of surface recombination is an important direction in SC research. In this…
The HeH$^+$ cation undergoes dissociative recombination with a free electron to produce neutral He and H fragments. We present calculations using ab initio quantum defects and Fano's rovibrational frame transformation technique, along with…
We re-examine the role of collisions in decoupling the HI 21-cm spin temperature from the cosmic microwave background (CMB). The cross section for de-exciting the 21-cm trasition in collisions with free electrons is more than 10 times…
The recombination production of $B_c$ mesons in heavy-ion collisions at the LHC energy is facilitated by the abundant and highly thermalized charm ($c$) quarks transported in the deconfined medium created. We study the production of $B_c$…
Accurate photodissociation cross sections have been obtained for the A-X electronic transition of HeH+ using ab initio potential curves and dipole transition moments. Partial cross sections have been evaluated for all rotational transitions…
We report measured rate coefficients for electron-ion recombination for Si10+ forming Si9+ and for Si9+ forming Si8+, respectively. The measurements were performed using the electron-ion merged-beams technique at a heavy-ion storage ring.…
The breakup cross sections in the reaction $^6$He+$^{12}$C are calculated at about 40 MeV/nucleon using the high-energy approximation (HEA) and with the help of microscopic optical potentials (OP) of interaction with the target nucleus…