Aims. We describe the assignment of a previously unidentified interstellar absorption line to ArH and discuss its relevance in the context of hydride absorption in diffuse gas with a low H2 fraction. The confidence of the assignment to ArH is discussed, and the column densities are determined toward several lines of sight. The results are then discussed in the framework of chemical models, with...

With the advent of Chandra and XMM, X-ray lines spectroscopy of AGN outflows is off to an exciting start. In this paper we illuminate some of the complications involved in extracting the outflow’s physical conditions (ionization equilibrium, total column density, chemical abundances) from such spectroscopic data. To do so we use the example provided by high-quality FUSE and HST observations of ...

This paper provides a general reference for deriving the ionizations and metal abundances for absorption-line clouds in photoionization equilibrium with a QSO spectrum. The results include a quantitative assessment of the theoretical uncertainties and firm lower limits on the metallicities when no ionization constraints are available. The calculations applied to the best available column densit...

    In this study, it was shown that how CO2 and H2S were removed from a natural gas stream, using a nanofluid containing nanoporous graphene in Diehanolamine (DEA). Before running the experiments, the appropriate values were chosen for the nanosheet dosage and the liquid and gas flow rates in the absorption experiments, which were performed in a laboratory scale wetted wall column. In the expe...

We present detailed analyses of the absorption spectrum seen in QSO 2359– 1241 (NVSS J235953−124148). Keck HIRES data reveal absorption from twenty transitions arising from: He i, Mg i, Mg ii, Ca ii, and Fe ii. HST data show broad absorption lines (BALs) from Al iii λ1857, C iv λ1549, Si iv λ1397, and Nv λ1240. Absorption from excited Fe ii states constrains the temperature of the absorber to 2...

We observed the Seyfert 1 galaxy NGC 3516 with the Goddard High Resolution Spectrograph on the Hubble Space Telescope, and obtained UV spectra at a resolution of λ/∆λ ≈ 20,000 in the redshifted C IV λ1549 region. The intrinsic C IV absorption in the core of the broad emission line is resolved for the first time into four distinct kinematic components, which are all blue-shifted relative to the ...