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

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Detecting neutral Hydrogen (H\,{\sc i}) via the 21~cm line emission from the intergalactic medium at $z\gtrsim 6$ has been identified as one of the most promising probes of the epoch of cosmic reionization -- a major phase transition of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Nithyanandan Thyagarajan , Chris Carilli , Bojan Nikolic

Context: Despite the low elemental deuterium abundance in the Galaxy, enhanced molecular D/H ratios have been found in the environments of low-mass star-forming regions and, in particular, the Class 0 protostar IRAS 16293-2422. Aims: The…

Astrophysics of Galaxies · Physics 2015-06-15 A. Coutens , C. Vastel , S. Cazaux , S. Bottinelli , E. Caux , C. Ceccarelli , K. Demyk , V. Taquet , V. Wakelam

Scattering and absorption properties at optical and ultraviolet wavelengths are calculated for an interstellar dust model consisting of carbonaceous grains and amorphous silicate grains. Polarization as a function of scattering angle is…

Astrophysics · Physics 2011-05-05 B. T. Draine

The dispersion of the dielectric function for wurtzite InN is analytically evaluated in the region near the fundamental energy gap. The real part of the dielectric function has a logarithmic singularity at the absorption edge. This results…

Materials Science · Physics 2009-11-13 L. A. Falkovsky

The H II region W40 harbors a small group of young, hot stars behind roughly 9 magnitudes of visual extinction. We have detected gaseous carbon monoxide (CO) and diatomic carbon (C_2) in absorption toward the star W40 IRS 1a. The 2-0 R0,…

Astrophysics · Physics 2009-10-31 R. Y. Shuping , T. P. Snow , R. Crutcher , B. L. Lutz

Adsorption of para-hydrogen films on Alkali metals substrates at low temperature is studied theoretically by means of Path Integral Monte Carlo simulations. Realistic potentials are utilized to model the interaction between two…

Statistical Mechanics · Physics 2009-11-11 M. Boninsegni

We used HST/STIS to obtain the spectrum of molecular hydrogen associated with the damped Ly$\alpha$ system at $z_{\rm abs}=1.7765$ toward the quasar Q1331+170 at $z_{\rm em}=2.084$. Strong ${\rm H}_2$ absorption was detected, with a total…

Astrophysics · Physics 2009-11-13 Jun Cui , Jill Bechtold , Jian Ge , David M. Meyer

We investigate the observability of hydrogen molecules in absorption. The absorption efficiency of the hydrogen molecules become comparable with or larger than that of the dust grains in the metal-poor condition expected in the early…

Astrophysics · Physics 2015-06-24 Hiroshi Shibai , Tsutomu T. Takeuchi , T. N. Rengarajan , Hiroyuki Hirashita

The detection of high gas-phase abundances of SO2 and SO in the cold envelope of an intermediate mass protostar suggests that these molecules might form on icy dust grains and subsequently desorb to the gas phase by non-thermal desorption…

We theoretically investigate the ground-state properties of a molecular para-hydrogen (p-H2) film in which crystallization is energetically frustrated by embedding sodium (Na) atoms periodically distributed in a triangular lattice. In order…

Materials Science · Physics 2015-06-17 Claudio Cazorla , Jordi Boronat

Absorption lines from molecular hydrogen ($\rm H_2$) in the spectra of background sources are a powerful probe of the physical conditions in intervening cold neutral medium. At high redshift, $z>2$, $\rm H_2$ lines are conveniently shifted…

Astrophysics of Galaxies · Physics 2022-03-30 Sergei Balashev , Pasquier Noterdaeme

The 21 cm hyperfine transition of the atomic hydrogen (HI) in ground state is a powerful probe of the neutral gas content of the universe. This radio frequency transition has been used routinely for decades to observe, both in emission and…

Astrophysics of Galaxies · Physics 2019-11-26 Preetha Saha , Nirupam Roy , Mukul Bhattacharya

Despite the low elemental deuterium abundance in the Galaxy, enhanced molecular D/H ratios have been found in the environments of low-mass star forming regions, and in particular the Class 0 protostar IRAS 16293-2422. The CHESS (Chemical…

Transiting planets, such as HD209458b, offer a unique opportunity to scrutinize the planetary atmospheric content. Although molecular hydrogen is expected to be the main atmospheric constituent, H2 remains uncovered because of the lack of…

Astrophysics · Physics 2009-11-13 A. Lecavelier des Etangs , A. Vidal-Madjar , J. -M. Desert , D. Sing

Scattering and absorption of X-rays by interstellar dust is calculated for a model consisting of carbonaceous grains and amorphous silicate grains. The calculations employ realistic dielectric functions with structure near X-ray absorption…

Astrophysics · Physics 2009-11-10 B. T. Draine

A theoretical description of IR spectroscopy data for a hydrogen bond (HB) is constructed on the base of trigonometric double-well potential for which an exact analytic solution of the one-dimensional Schr\"odinger equation (SE) is…

Chemical Physics · Physics 2020-08-21 A. E. Sitnitsky

We study the impact of neutral hydrogen absorption on ${\rm H_2}$ photodissociation in protogalactic haloes exposed to soft-UV radiation. Lyman-series absorption can significantly deplete dissociating photons as line overlap with the ${\rm…

Astrophysics of Galaxies · Physics 2022-10-19 Meredith Neyer , Jemma Wolcott-Green

This study presents results on detecting neutral atomic hydrogen (HI) 21cm absorption in the spectrum of PKS1413+135 at redshift $z=0.24670041$. The observation was conducted by FAST, with a spectral resolution of 10 Hz, using 10 minutes of…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-08 Jiangang Kang , Chang-Zhi Lu , TongJie Zhang , Ming Zhu

We present the detection of the average H$_2$ absorption signal in the overall population of neutral gas absorption systems at $z\sim 3$ using composite absorption spectra built from the Sloan Digital Sky Survey-III damped Lyman-$\alpha$…

Astrophysics of Galaxies · Physics 2018-05-02 Sergei Balashev , Pasquier Noterdaeme

The complex dielectric functions of LiNbO$_2$ were determined using optical transmittance and reflectance spectroscopies at room temperature. The measured dielectric function spectra reveal distinct structures at several bandgap energies.…

Materials Science · Physics 2023-10-30 T. Kurachi , T. Yamaguchi , E. Kobayashi , T. Soma , A. Ohtomo , T. Makino
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