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Related papers: Interstellar Solid Hydrogen

200 papers

Carbon dioxide (CO$_2$) is one of the most important interstellar molecules. While it is considered that it forms on the surface of interstellar dust grains, the exact contribution of different chemical mechanisms is still poorly…

We report the results of initial FUSE observations of molecular hydrogen (H2) in translucent clouds. These clouds have greater optical depth than any of the diffuse clouds previously observed for far-UV H2 absorption, and provide new…

We present a comprehensive study of MHD waves and instabilities in a weakly ionised system, e.g., an interstellar molecular cloud. We determine all the critical wavelengths of perturbations across which the sustainable wave modes can change…

Solar and Stellar Astrophysics · Physics 2011-04-01 Telemachos Ch. Mouschovias , Glenn E. Ciolek , S. A. Morton

We study the connection of star formation to atomic (HI) and molecular hydrogen (H$_2$) in isolated, low metallicity dwarf galaxies with high-resolution ($m_{\rm gas}$ = 4 M$_\odot$, $N_{\rm ngb}$ = 100) SPH simulations. The model includes…

Astrophysics of Galaxies · Physics 2016-03-23 Chia-Yu Hu , Thorsten Naab , Stefanie Walch , Simon C. O. Glover , Paul C. Clark

We performed high-resolution, 3D MHD simulations and we compared to observations of translucent molecular clouds. We show that the observed populations of rotational levels of H2 can arise as a consequence of the multi-phase structure of…

Instrumentation and Methods for Astrophysics · Physics 2016-06-01 V. Valdivia , P. Hennebelle , M. Gerin , P. Lesaffre

With the presence of evermore complex S-bearing molecules being detected lately, studies on their chemical formation routes need to keep up the pace to rationalize observations, suggest new candidates for detection, and provide input for…

Astrophysics of Galaxies · Physics 2022-01-05 Germán Molpeceres , Juan García de la Concepción , Izaskun Jiménez Serra

This paper presents a statistical explanation of filament formation in the galactic atomic hydrogen. Recently developed technique allows to determine the 3D spectrum of random HI density. We claim that even in the absence of dynamical…

Astrophysics · Physics 2009-10-28 Alex Lazarian , Dmitri Pogosyan

Observations of CO+ suggest column densities on the order 10^12 cm^-2 that can not be reproduced by many chemical models. CO+ is more likely to be destroyed than excited in collisions with hydrogen. An anomalous excitation mechanism may…

Solar and Stellar Astrophysics · Physics 2015-05-13 Pascal Staeuber , Simon Bruderer

Amorphous solid water (ASW) is abundantly present in the interstellar medium, where it forms a mantle on interstellar dust particles and it is the precursor for cometary ices. In space, ASW acts as substrate for interstellar surface…

Materials Science · Physics 2020-09-03 J. A. Noble , H. M. Cuppen , S. Coussan , B. Redlich , S. Ioppolo

Protonated molecular species have been proven to be abundant in the interstellar gas. This class of molecules is also pivotal for the determination of important physical parameters for the ISM evolution (e.g. gas ionisation fraction) or as…

A new molecular hydrogen cloud is found in the sub-damped Ly-alpha absorber [log N(HI)=19.88+/-0.05] at the redshift z=1.15 toward the bright quasar HE0515-4414 (zem = 1.71). More than 30 absorption features in the Lyman band system of H2…

Astrophysics · Physics 2009-11-10 D. Reimers , R. Baade , R. Quast , S. A. Levshakov

There has always been a great deal of interest in the formation of H2 as well as in the binding energy released upon its formation on the surface of dust grains. The present work aims at collecting experimental evidence for how the bond…

Through density functional theory and molecular dynamics calculations, we have analysed various metal polyhydrides to understand whether hydrogen is present in its molecular or atomic form - tetrahydrides of Ba,Sr,Ra, Cs and La;…

Materials Science · Physics 2023-04-27 Miriam Marqués , Miriam Pena Alvarez , Miguel Martinez-Canales , Graeme J Ackland

Ultra-luminous infrared galaxies are among the most luminous objects in the local universe and are thought to be powered by intense star formation. It has been shown that in these objects the rotational spectral lines of molecular hydrogen…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Nadia L. Zakamska

We investigate the abundance of galactic molecular hydrogen (H$_2$) in the "Evolution and Assembly of GaLaxies and their Environments" (EAGLE) cosmological hydrodynamic simulations. We assign H$_2$ masses to gas particles in the simulations…

Stellar and nebular abundance indicators reveal that there exists significant abundance fluctuations in the interstellar medium (ISM) of gas-rich galaxies. It is shown that at the present observed solar level of O/H $\sim 6 \times 10^{-4}$,…

Astrophysics · Physics 2007-05-23 Jean-Rene ROY , Daniel KUNTH

Due to our vantage point in the disk of the Galaxy, its 3D structure is not directly accessible. However, knowing the spatial distribution, e.g. of atomic and molecular hydrogen gas is of great importance for interpreting and modelling…

Astrophysics of Galaxies · Physics 2023-09-26 Laurin Söding , Philipp Mertsch , Vo Hong Minh Phan

It is a fact that interstellar formation processes are thermodynamically affected. Based on this, the seven heterocycles; imidazole, pyridine, pyrimidine, pyrrole, quinoline, isoquinoline and furan that have been searched for from different…

Astrophysics of Galaxies · Physics 2021-09-08 Emmanuel E. Etim , ROA Adelagun , Chrysanthus Andrew , Oladimeji Enock Oluwole

We investigate the leading systematic effects in ro-vibrational spectroscopy of the molecular hydrogen ions H2+ and HD+, in order to assess their potential for the realization of optical clocks that would be sensitive to possible variations…

Atomic Physics · Physics 2017-02-20 Jean-Philippe Karr

Molecular hydrogen is an important component of galaxies because it fuels star formation and accretion onto AGN, the two processes that generate the large infrared luminosities of gas-rich galaxies. Observations of spectral-line emission…

Astrophysics · Physics 2015-06-24 Padeli Papadopoulos , Rob Ivison , Chris Carilli , Geraint Lewis