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Related papers: The infrared dielectric function of solid para-hyd…

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We present the analysis of a sub-DLA system (log N(H^0)=20.0+/-0.15, z_abs=2.69) toward SDSS J123714+064759 (z_em=2.78). Using the VLT/UVES and X-shooter spectrographs, we detect H2, HD and CO molecules in absorption with log…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 P. Noterdaeme , P. Petitjean , C. Ledoux , S. Lopez , R. Srianand , S. D. Vergani

Ro-vibrational absorption lines of H$_2$O in the 5-8 $\mu$m wavelength range selectively probe gas against the mid-infrared continuum emitting background of the inner regions of YSOs and AGN and deliver important information about these…

Instrumentation and Methods for Astrophysics · Physics 2024-06-11 Jialu Li , Adwin Boogert , Alexander G. G. M. Tielens

We present a new ultra-violet spectrum of the QSO 0013-004 with 0.9 \AA resolution obtained with the MMT Blue spectrograph. The \upsilon = 0 - 0, 1 - 0, 2 - 0 and 3 - 0 Lyman bands of H_2 associated with the z = 1.9731 damped Ly alpah…

Astrophysics · Physics 2016-08-30 Jian Ge , Jill Bechtold

Our aim is to compare the infrared properties of big, ``classical'' dust grains with visual extinction in the cloud L1642. In particular, we study the differences of grain emissivity between diffuse and dense regions in the cloud. The…

Astrophysics · Physics 2009-11-13 K. Lehtinen , M. Juvela , K. Mattila , D. Lemke , D. Russeil

In recent decades, significant attention has been dedicated to analytical and observational studies of the atomic hydrogen (HI) to molecular hydrogen (H2) transition in the interstellar medium. We focussed on the Draco diffuse cloud to gain…

The dielectric function of the wide-gap optical material HfO2 is investigated by the local density approximation (LDA) +U approach. We focus on the origin of the shoulder-like structure near the edge of the band gap in the imaginary part of…

Materials Science · Physics 2016-01-06 Jinping Li , Songhe Meng , Liyuan Qin , Hantao Lu , Takami Tohyama

We present measurements of the 3.4-micron hydrocarbon dust absorption feature, and four visual diffuse interstellar bands, for twelve highly reddened (9.0<A(V)<15.8), early-type stars identified from the Stephenson (1992) catalogue,…

Astrophysics · Physics 2009-11-07 M. G. Rawlings , A. J. Adamson , D. C. B. Whittet

There is a robust polyatomic chemistry in diffuse, partially-molecular interstellar gas that is readily accessible in absorption at radio/mm/sub-mm wavelengths. Accurate column densities are derived owing to the weak internal excitation, so…

Astrophysics of Galaxies · Physics 2023-02-15 Harvey Liszt , Maryvonne Gerin

We perform detailed spectroscopic analysis and numerical modelling of an H2-bearing damped Lyman-alpha absorber (DLA) at zabs = 2.05 towards the quasar FBQS J2340-0053. Metal absorption features arise from fourteen components spread over…

Astrophysics of Galaxies · Physics 2018-09-05 Katherine Rawlins , Raghunathan Srianand , Gargi Shaw , Hadi Rahmani , Rajeshwari Dutta , Sajeev Chacko

We aim to compare variations in the full-UV dust extinction curve (912-3000 Angstrom), with the HI/H$_2$/total H content along diffuse Milky Way sightlines, to investigate possible connections between ISM conditions and dust properties. We…

Astrophysics of Galaxies · Physics 2023-02-15 Dries Van De Putte , Stefan I. B. Cartledge , Karl D. Gordon , Geoffrey C. Clayton , Julia Roman-Duval

The interaction between electromagnetic microwaves (40-200 GHz) and superfluid helium in a stationary electric field has been investigated experimentally. It is found that the narrow line of resonance absorption at the roton frequency is…

Other Condensed Matter · Physics 2008-07-31 A. S. Rybalko , S. P. Rubets , E. Ya. Rudavskii , V. A. Tikhiy , R. Golovachenko , V. N. Derkach , S. I. Tarapov

We employed a fully optimized Shadow Wave Function (SWF) in combination with Variational Monte Carlo techniques to investigate the properties of HD molecules and molecular ortho-deuterium (o-D_2) in bulk solid para-hydrogen (p-H_2).…

Other Condensed Matter · Physics 2013-05-29 Francesco Operetto , Francesco Pederiva

Despite being one of the weakest dimers in nature, low-spectral-resolution Voyager/IRIS observations revealed the presence of (H$_2$)$_2$ dimers on Jupiter and Saturn in the 1980s. However, the collision-induced H$_2$-H$_2$ opacity…

Earth and Planetary Astrophysics · Physics 2018-03-28 L. N. Fletcher , M. Gustafsson , G. S. Orton

We report the detection of HI absorption towards the inner double of the double-double radio galaxy (DDRG) J1247+6723 with the Giant Metrewave Radio Telescope (GMRT). The inner double is a Giga-hertz peaked spectrum (GPS) source with a…

Astrophysics · Physics 2008-11-26 D. J. Saikia , Neeraj Gupta , C. Konar

We use far-UV absorption spectra obtained with FUSE towards three late B stars to study the formation and excitation of H2 in the diffuse ISM. The data interpretation relies on a model of the chemical and thermal balance in…

Under a pressure of ~150 GPa solid molecular hydrogen undergoes a phase transition accompanied by a dramatic rise in infra-red absorption in the vibron frequency range. We use the Berry's phase approach to calculate the electric…

Condensed Matter · Physics 2009-10-31 Ivo Souza , Richard M. Martin

Experimental and theoretical results for the dissociative adsorption of H_2 on vicinal Si(001) surfaces are presented. Using optical second-harmonic generation, sticking probabilities at the step sites are found to exceed those on the…

Condensed Matter · Physics 2009-10-31 P. Kratzer , E. Pehlke , M. Scheffler , M. B. Raschke , U. Hofer

To interpret H_2 quasar absorption line observations in Damped Ly-alpha clouds (DLAs), we model the H_2 spatial distribution within a DLA. Based on numerical simulations of disk structures with parameters similar to those derived for such…

Astrophysics · Physics 2009-11-07 H. Hirashita , A. Ferrara , K. Wada , P. Richter

We report results from a FUSE survey of interstellar molecular hydrogen (H2) in the Galactic disk toward 139 O-type and early B-type stars at Galactic latitudes $|b| < 10^{\circ}$, with updated photometric and parallax distances. The H2…

Astrophysics of Galaxies · Physics 2021-04-21 J. Michael Shull , Charles W. Danforth , Katherine L. Anderson

Recent experiments on the silicon terminated $3\times 2$ SiC(100) surface indicated an unexpected metallic character upon hydrogen adsorption. This effect was attributed to the bonding of hydrogen to a row of Si atoms and to the…

Materials Science · Physics 2009-11-11 R. Di Felice , C. M. Bertoni , C. A. Pignedoli , A. Catellani