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Related papers: Diffusive vs. non-diffusive paths to interstellar …

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Observational studies of HII region-molecular cloud interactions constrain models of feedback and quantify its impact on the surrounding environment. A recent hypothesis proposes that a characteristic spectral signature in ground state…

This study is aimed to contribute to a more comprehensive understanding of the molecular hydrogen distribution in the galaxy M33 by introducing novel methods for generating high angular resolution (18.2$''$, equivalent to 75 pc) column…

We have introduced a new method of estimating the electron temperature and density of H II regions by using single dish observations. In this method, multiple hydrogen radio recombination lines of different bands are computed under the…

Solar and Stellar Astrophysics · Physics 2019-11-14 F. -Y. Zhu , Q. -F. Zhu , J. -Z. Wang , J. -S Zhang

Dust plays a key role during star, disk and planet formation. Yet, its dynamics during the protostellar collapse remains a poorly investigated field. Recent studies seem to indicate that dust may decouple efficiently from the gas during…

Solar and Stellar Astrophysics · Physics 2020-09-23 Ugo Lebreuilly , Benoît Commerçon , Guillaume Laibe

My thesis work aims to study the inter-relation between various physical and chemical conditions in a wide range of astrophysical environments. Our studied regions range from the super-hot regions (i.e., nebular, photon-dominated, or…

Solar and Stellar Astrophysics · Physics 2022-08-12 Milan Sil

Energy redistribution after a chemical reaction is one of the few mechanisms to explain the diffusion and desorption of molecules which require more energy than the thermal energy available in quiescent molecular clouds (10 K). This energy…

Astrophysics of Galaxies · Physics 2023-05-10 Germán Molpeceres , Viktor Zaverkin , Kenji Furuya , Yuri Aikawa , Johannes Kästner

A model Hamiltonian for the reaction CH$_4^+ \rightarrow$ CH$_3^+$ + H, parametrized to exhibit either early or late inner transition states, is employed to investigate the dynamical characteristics of the roaming mechanism. Tight/loose…

Chemical Physics · Physics 2015-06-18 F. A. L. Mauguière , P. Collins , G. S. Ezra , S. C. Farantos , S. Wiggins

1-propanol (CH3CH2CH2OH) is a three carbon-bearing representative of primary linear alcohols that may have its origin in the cold dark cores in interstellar space. To test this, we investigated in the laboratory whether 1-propanol ice can…

Solar and Stellar Astrophysics · Physics 2019-06-26 D. Qasim , G. Fedoseev , K. -J. Chuang , V. Taquet , T. Lamberts , J. He , S. Ioppolo , E. F. van Dishoeck , H. Linnartz

Chemical reactions on dust grains are of crucial importance in interstellar chemistry because they produce molecular hydrogen and various organic molecules. Due to the submicron size of the grains and the low flux, the surface populations…

Astrophysics · Physics 2009-11-10 Azi Lipshtat , Ofer Biham

Molecular hydrogen is the most abundant molecule in the universe. It is the first one to form and survive photo-dissociation in tenuous environments. Its formation involves catalytic reactions on the surface of interstellar grains. The…

Ion beam therapy is one of the most progressive methods in cancer treatment. Studies of the water radiolysis process show that the most long-living species that occur in the medium of a biological cell under the action of ionizing…

Biological Physics · Physics 2021-02-24 D. V. Piatnytskyi , O. O. Zdorevskyi , S. N. Volkov

The interstellar medium is characterized by a rich and diverse chemistry. Many of its complex organic molecules are proposed to form through radical chemistry in icy grain mantles. Radicals form readily when interstellar ices (composed of…

Astrophysics of Galaxies · Physics 2016-09-13 Karin I. Oberg

We have used the master equation approach to study a moderately complex network of diffusive reactions occurring on the surfaces of interstellar dust particles. This network is meant to apply to dense clouds in which a large portion of the…

Astrophysics · Physics 2009-11-10 T. Stantcheva , V. I. Shematovich , E. Herbst

Aims: The production of molecular hydrogen and its deuterated forms onto carbonaceous dust grains is investigated in detail. The goal of this study is to estimate the importance of the chemistry occuring on grain surfaces for the…

Astrophysics · Physics 2009-11-13 S. Cazaux , P. Caselli , V. Cobut , J. Le Bourlot

We present a model for the hydrogenation states of Polycyclic Aromatic Hydrocarbons (PAHs) in the diffuse interstellar medium. First, we study the abundance of hydrogenation and charge states of PAHs due to photo-ionization,…

Astrophysics · Physics 2007-05-23 My Ha Vuong , Bernard H. Foing

The surface processes on interstellar dust grains have an important role in the chemical evolution in molecular clouds. Hydrogenation reactions on ice surfaces have been extensively investigated and are known to proceed at low temperatures…

Astrophysics of Galaxies · Physics 2021-01-11 Masashi Tsuge , Hiroshi Hidaka , Akira Kouchi , Naoki Watanabe

Understanding the damage of DNA bases from hydrogen abstraction by free OH radicals is of particular importance to reveal the effect of hydroxyl radicals produced by the secondary effect of radiation. Previous studies address the problem…

Computational Physics · Physics 2016-09-28 Ramin M. Abolfath , P. K. Biswas , R. Rajnarayanam , Thomas Brabec , Reinhard Kodym , Lech Papiez

Context. Polarized dust emission can be used as a probe for magnetic fields at different scales. In particular, the analysis of the relative orientation between the density structures and the magnetic field projected on the plane of the sky…

Astrophysics of Galaxies · Physics 2021-03-24 Elisabetta R. Micelotta , Mika Juvela , Paolo Padoan , Isabelle Ristorcelli , Dana Alina , Johanna Malinen

Methods: The microscopic equations of H2-formation and protonation are integrated numerically over time in such a manner that the overall structures evolve self-consistently under benign conditions. Results: The equilibrium H2 formation…

Astrophysics of Galaxies · Physics 2009-11-13 H. S. Liszt

In this paper, we revisit the hydrogen recombination history from a novel perspective: the evolution of chemical potentials. We derive expressions for the chemical potentials, which depend on the thermal bath temperature and the ionization…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-07 L. L. Sales , F. C. Carvalho , H. T. C. M. Souza