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A room temperature line list for the H 2 15O radioactive isotopologue of the water molecule is computed using the variational nuclear-motion DVR3D program suite and an empirical high-precision potential energy function. The line list consists of rotation-vibrational energies and Einstein-A coefficients, covering a wide spectral range from 0 to 25000 cm − 1 and the total angular momenta J up to 30. Estimates of air-broadening coefficients are provided. Experimentally derived energies of H 2 16 O, H 2 17 O and H 2 18 O from the literature are used to provide improved energies for important states with uncertainty estimates for the H 2 15O. A number of the wmost promising spectroscopic ranges for the detection of H 2 15O are proposed. The calculated absorption spectrum should be useful for the study gaseous radioactive water at IR region, determining concentration, etc. [ABSTRACT FROM AUTHOR]

Absolute single-photoionization cross sections for aluminum-like P 2+ have been measured from 26.5 to 66.5 eV using photoion yield spectroscopy. In addition, absolute cross section measurements for the single-photoionization of magnesium-like P 3+ have been measured from 43 to 60 eV. For both ions, the measured spectra are dominated by Rydberg series resonances superimposed on a non-resonant direct photoionization cross section. Analyses of these data have helped identify the initial and final states of the Rydberg series observed in each photoion. In addition, quantum defects are derived for each series. [ABSTRACT FROM AUTHOR]

The photoionization of Cl + leading to Cl 2+ was measured in the photon energy range of 19.5–28.0 eV. A spectrum with a photon energy resolution of 15 meV normalized to absolute cross-section measurements is presented. The measurements were carried out by merging a Cl + ion beam with a photon beam of highly monochromatic synchrotron radiation at the Advanced Light Source at Lawrence Berkeley National Laboratory. The measured photoionization of Cl + consists of several autoionization resonances surperimposed on the direct photoionization signal. Most of the prominent resonances are assigned to members of Rydberg series originating from the singlet ground state and from metastable triplet levels within the ground-state configuration of Cl + . The direct ionization cross section is no larger than 12 Mb. [ABSTRACT FROM AUTHOR]

Abstract: We report sensitive Chandra X-ray non-detections of two unusual, luminous Iron Low-Ionization Broad Absorption Line Quasars (FeLoBALs). The observations do detect a non-BAL, wide-binary companion quasar to one of the FeLoBAL quasars. We combine X-ray-derived column density lower limits (assuming solar metallicity) with column densities measured from ultraviolet spectra and CLOUDY photoionization simulations to explore whether constant-density slabs at broad-line region densities can match the physical parameters of these two BAL outflows, and find that they cannot. In the “overlapping-trough” object SDSS J0300+0048, we measure the column density of the X-ray absorbing gas to be N H ⩾1.8×1024 cm−2. From the presence of Fe ii UV78 absorption but lack of Fe ii UV195/UV196 absorption, we infer the density in that part of the absorbing region to be n e ≃106 cm−3. We do find that a slab of gas at that density might be able to explain this object’s absorption. In the Fe iii-dominant object SDSS J2215–0045, the X-ray absorbing column density of N H ⩾3.4×1024 cm−2 is consistent with the Fe iii-derived N H ⩾2×1022 cm−2 provided the ionization parameter is log U >1.0 for both the n e =1011 cm−3 and n e =1012 cm−3 scenarios considered (such densities are required to produce Fe iii absorption without Fe iiabsorption). However, the velocity width of the absorption rules out its being concentrated in a single slab at these densities. Instead, this object’s spectrum can be explained by a low density, high ionization and high temperature disk wind that encounters and ablates higher density, lower ionization Fe iii-emitting clumps. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a modification of the cumulative wavenumber (CW) method to determine the radiative heat flux in non-uniform participating gases. Previous works in the literature have shown that the CW method renders accurate estimates of the radiative volumetric heat source in the medium. However, as will be shown in this work, the radiative heat flux can present considerable deviation of the correct solution, which results from the radiative energy balance not being satisfied by the CW method. A modification of the method is devised in this work to satisfy the radiative energy balance while keeping the same value of the radiative volumetric heat source. The proposed methodology is applied together with the discrete ordinates method to solve the radiation heat transfer in a one-dimensional slab containing a non-isothermal layer of carbon dioxide. The results are compared to the benchmark line-by-line (LBL) integration, and show that the modified CW method can satisfy the radiative energy balance, improving the estimation of the radiative heat flux in the medium. [ABSTRACT FROM AUTHOR]

Abstract: A sample of three quasar spectra observed by the Keck telescope is selected to reconstruct the perturbations of mass density using the Gaussianization method, with a calculation of the corresponding wavelet power spectra. The two parameters in the lognormal (LN) model, namely the shape factor Γ and the Jeans smoothing factor r, are set as free parameters. Their most probable values are determined by comparing the result of statistical analysis on the observed sample with that on a simulated sample, and they are: Γ0.50 and r0.09. Non-Gaussian features in the quasar spectra can not be excluded using the traditional Gaussianization method. However, on the scales larger than 100 kpc, these features have little or no influence on our results described above. This argument has been verified by comparing the observed sample with the simulated sample as regards their skewness and kurtosis spectra, as well as their scale-scale correlations. [Copyright &y& Elsevier]

Abstract: We present a calculation of the damping of an ultra-energetic cosmic neutrino (UHEν) travelling through the thermal gas of relic neutrinos, using the formalism of finite-temperature field theory. From the self-energy diagram due to Z exchange, we obtain the annihilation cross-section for an UHEν interacting with an antineutrino from the background. This method allows us to derive the full expression for the UHEν transmission probability, taking into account the momentum of relic neutrinos. We discuss the effect of thermal motion on the shape of the absorption dips for different UHEν fluxes as well as in the context of relic neutrino clustering. We find that for ratios of the neutrino mass to the relic background temperature 102 or smaller, the thermal broadening of the absorption lines could significantly affect the determination of the neutrino mass and of the characteristics of the population of UHEν sources. [Copyright &y& Elsevier]

Abstract: Energetic outflows appear to occur in conjunction with active mass accretion onto supermassive black holes. These outflows are most readily observed in the ∼10% of quasars with broad absorption lines, where the observer’s line of sight passes through the wind. Until fairly recently, the paucity of X-ray data from these objects was notable, but now sensitive hard-band missions such as Chandra and XMM-Newton are routinely detecting broad absorption line quasars. The X-ray regime offers qualitatively new information for the understanding of these objects, and these new results must be taken into account in theoretical modeling of quasar winds. [Copyright &y& Elsevier]

Absorption L-lines of iron ions are observed, in absorption, in spectra of Seyfert 1 galaxies by the new generation of X-ray satellites: Chandra (NASA) and XMM-Newton (ESA). Lines associated to Fe23+ to Fe17+ are well resolved. Whereas, those corresponding to Fe16+ to Fe6+ are unresolved. Forbidden transitions of the Fe16+ to Fe6+ ions were previously observed, for the same objects, in the visible and infra-red regions, showing that the plasma had a low density. To interpret X-ray, visible and infra-red data, astrophysical models assume an extended absorbing medium of very low density surrounding an intense X-ray source. We have calculated atomic data (wavelengths, radiative and autoionization rates) for n=2 to n′=3–4 transitions and used them to construct refined synthetic spectra of the unresolved part of the L-line spectra. [Copyright &y& Elsevier]

We summarise the properties of the absorbing haloes around two high-redshift radio galaxies studied with the VLT-UVES echelle spectrograph. The absorbers in 0943−242 (z=2.92) exhibit little further structure compared with previous data—the main absorber still has N(HI)≃1019 cm−2—reinforcing the picture in which the absorbing gas occupies a smooth shell beyond the emission line halo. In 0200+015 (z=2.23) the main absorber now splits into two spatially-resolved systems with N(HI)≃4×1014 cm−2, one of which has strong CIV absorption, implying a metallicity of Z≃10 Z◎. We explain the differences between the two sources with an evolutionary scenario, invoking interaction with the expanding radio source and metal enrichment via a starburst superwind. [Copyright &y& Elsevier]