The absorption spectrum of short-lived isotopic variant of water, H₂¹⁵O: Tentative detection at the Earth's atmosphere

A calculated infrared vibration–rotation spectrum of isotopically modified water, H215O, is presented. Oxygen-15 has a half-life of about 2 minutes and H215O may be formed in the atmosphere during thunderstorms as a result of photonuclear processes or when the atmosphere is irradiated by cosmic γ-rays. Variational nuclear motion calculations of vibrational and vibrational-rotational levels up to 25000 cm−1 and up to J = 10 in angular momentum are performed within the framework of the Born-Oppenheimer approximation using an accurate water potential function. The line shape parameters for H215O are estimated. Spectral ranges that are promising for the detection of H215O in the atmosphere are identified and a search for spectral signatures conducted. A spectral feature is tentatively assigned to the 752 (0 1 0) - 643 (0 0 0) line of H215O

Interstellar Turbulence II: Implications and Effects

Interstellar turbulence has implications for the dispersal and mixing of the elements, cloud chemistry, cosmic ray scattering, and radio wave propagation through the ionized medium. This review discusses the observations and theory of these effects. Metallicity fluctuations are summarized, and the theory of turbulent transport of passive tracers is reviewed. Modeling methods, turbulent concentration of dust grains, and the turbulent washout of radial abundance gradients are discussed. Interstellar chemistry is affected by turbulent transport of various species between environments with different physical properties and by turbulent heating in shocks, vortical dissipation regions, and local regions of enhanced ambipolar diffusion. Cosmic rays are scattered and accelerated in turbulent magnetic waves and shocks, and they generate turbulence on the scale of their gyroradii. Radio wave scintillation is an important diagnostic for small scale turbulence in the ionized medium, giving information about the power spectrum and amplitude of fluctuations. The theory of diffraction and refraction is reviewed, as are the main observations and scintillation regions.Comment: 46 pages, 2 figures, submitted to Annual Reviews of Astronomy and Astrophysic

Reaction rates and transport in neutron stars

Understanding signals from neutron stars requires knowledge about the transport inside the star. We review the transport properties and the underlying reaction rates of dense hadronic and quark matter in the crust and the core of neutron stars and point out open problems and future directions.Comment: 74 pages; commissioned for the book "Physics and Astrophysics of Neutron Stars", NewCompStar COST Action MP1304; version 3: minor changes, references updated, overview graphic added in the introduction, improvements in Sec IV.A.

The infrared absorption spectrum of radioactive water isotopologue H<inf>2</inf>¹⁵O

A room temperature line list for the H215O 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 H216O, H217O and H218O from the literature are used to provide improved energies for important states with uncertainty estimates for the H215O. A number of the wmost promising spectroscopic ranges for the detection of H215O are proposed. The calculated absorption spectrum should be useful for the study gaseous radioactive water at IR region, determining concentration, etc