Related papers: The infrared dielectric function of solid para-hyd…
Molecular hydrogen normally has only weak, quadrupole transitions between its rovibrational states, but in a static electric field it acquires a dipole moment and a set of allowed transitions. Here we use published ab initio calculations of…
We report on the first far-IR detection of H2D+, using the Infrared Space Observatory, in the line of sight toward Sgr B2 in the galactic center. The transition at 126.853 um connecting the ground level of o-H2D+, 1_1,1 with the the 2_1,2…
Hydrogen is one of the few molecules which has been incarcerated in the molecular cage of C$_{60}$ and forms endohedral supramolecular complex H$_2$@C$_{60}$. In this confinement hydrogen acquires new properties. Its translational motion…
Hydrogenated amorphous carbon (a-C:H) has been proposed as one of the carbonaceous solids detected in the interstellar medium. Energetic processing of the a-C:H particles leads to the dissociation of the C-H bonds and the formation of…
We study molecular para-hydrogen (p-${\rm H_{2}}$) and ortho-deuterium (o-${\rm D_{2}}$) in two dimensions and in the limit of zero temperature by means of the diffusion Monte Carlo method. We report energetic and structural properties of…
The absorption of infrared and visible radiation from stellar emission spectra by the negatively charged hydrogen ions H$^{-}$ is considered. We derive the explicit formulas for the bound-free absorption coefficient $a_{\nu}$ for the…
We have conducted a study combining H2O lines in two spectral regions. First, Infrared Space Observatory observations of several H2O thermal lines seen in absorption toward Sgr B2(M) at a spectral resolution of 35 kms^-1 have been analyzed.…
Near- and mid-IR absorption spectra of endohedral H2@C60+ have been measured using He-tagging. The samples have been prepared using a 'molecular surgery' synthetic approach and were ionized and spectroscopically characterized in the gas…
We present a multiwavelength study of 28 Galactic massive star-forming H II regions. For 17 of these regions, we present new distance measurements based on Gaia DR2 parallaxes. By fitting a multicomponent dust, blackbody, and power-law…
Measuring rest-frame ultraviolet rotational transitions from the Lyman and Werner bands in absorption against a bright background continuum is one of the few ways to directly measure molecular hydrogen (H2). Here we report the detection of…
We analyze Ly-alpha fluoresced H2 lines observed in the UV spectrum of Mira B. We identify 13 different sequences fluoresced by 13 different H2 transitions within the Ly-alpha line. The observed H2 line ratios within these sequences imply…
We calculated the phase diagram of the second layer of $para$-H$_2$ adsorbed on graphite using quantum Monte Carlo methods. The second layer shows an incommensurate triangular crystal structure. By using a symmetric wave function, that…
Hydrogen is a promising element for applications in new energy sources like fuel cells. One key issue for such applications is storing hydrogen. And, to improve storage capacity, understanding the interaction mechanism between hydrogen and…
We present JHK surface photometry of 15 highly inclined, late-type (Sab-Sc) spirals and investigate the quantitative effects of dust extinction. Using the (J - H, H - K) two-color diagram, we compare the color changes along the minor axis…
We discuss the interstellar absorption from many atomic and molecular species seen in high-resolution $HST$/STIS UV and high-S/N optical spectra of the moderately reddened B3-5~V star HD~62542. This remarkable sight line exhibits both very…
We consider how the infrared intensity of an O-H stretch in a hydrogen bonded complex varies as the strength of the H-bond varies from weak to strong. We obtain trends for the fundamental and overtone transitions as a function of…
We report diffusion Monte Carlo calculations on the phase diagrams of para-H2 and ortho-D2 adsorbed on top of a first layer of the same substances on graphene. We found that the ground state of the second layer is a triangular…
We study the low temperature properties of a single layer of parahydrogen adsorbed on graphene, by means of Quantum Monte Carlo simulations. The computed phase diagram is very similar to that of helium on the same substrate, featuring…
The abundance of H2 in molecular clouds, relative to the commonly used tracer CO, has only been measured toward a few embedded stars, which may be surrounded by atypical gas. We present observations of near-infrared absorption by H2, CO,…
For semiconductors and semimetals possessing a narrow gap between bands with different parity, the dispersion of the dielectric function is explicitly evaluated in the infrared region. The imaginary part of the dielectric function has a…