English
Related papers

Related papers: Merged ionization/dissociation fronts in planetary…

200 papers

Branching ratios for fragmentation channels of important meta- and unstable species are essential for a molecular-level characterization of atmospheric chemistry. Here, the molecular product channels for the decomposition dynamics of the…

Chemical Physics · Physics 2026-01-21 Cangtao Yin , Markus Meuwly

The nuclei of merging galaxies are often deeply buried in dense layers of gas and dust. In these regions, gas outflows driven by starburst and AGN activity are believed to play a crucial role in the evolution of these galaxies. However, to…

We obtained high-resolution VLT and FUSE spectra of the quasar HE2347-4342 to study the properties of the intergalactic medium between redshifts z=2.0-2.9. The high-quality optical spectrum allows us to identify approximately 850 HeII…

Roaming has been proposed as a possible mechanism contributing to molecular dissociation in which the fragments can move around one another at relatively large intermolecular distances before separating entirely. While roaming, there is…

A search for O VI at redshifts corresponding to Ly-alpha lines in the z_em ~ 2.4 QSOs HE1122-1648 and HE2217-2818 reveals that a substantial fraction of those with H I column densities log N(HI) > 14 (cm^{-2}) are highly ionized and show…

Astrophysics · Physics 2009-11-07 Robert F. Carswell , Joop Schaye , Tae-Sun Kim

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

Ultraviolet irradiation of ice is of great interest for understanding the chemistry in both atmospheric and astrophysical environments. In interstellar space, photodissociation of H2O molecules can be a driving force behind the chemistry on…

Astrophysics · Physics 2016-08-30 Stefan Andersson , Geert-Jan Kroes , Ewine F. van Dishoeck

The thermochemistry of H2 and HD in non-collapsed, non-reionized primordial gas up to the end of the dark age is investigated with recent radiation-matter and chemical reaction rates taking into account the efficient coolant HD, and the…

Astrophysics · Physics 2009-11-07 D. Pfenniger , D. Puy

The cross sections for the production of hadrons in quasi-real photon-photon collisions in proton-proton and heavy ion interactions are compared with the corresponding cross sections for central diffraction and for photon-pomeron…

High Energy Physics - Phenomenology · Physics 2008-02-03 R. Engel , M. A. Braun , C. Pajares , J. Ranft

We model the temperature and chemical structure of molecular clouds as a function of depth into the cloud, assuming a cloud of constant density n illuminated by an external FUV (6 eV < E < 13.6 eV) flux G_0 (scaling factor in multiples of…

Astrophysics · Physics 2011-02-11 David Hollenbach , Michael J. Kaufman , Edwin A. Bergin , Gary J. Melnick

Low-energy cosmic rays ($E\lesssim 1$ GeV) are responsible for the ionisation and heating of molecular clouds. While the role of supra-thermal electrons produced in the ionisation process in inducing excitation of the ambient gas (mostly…

High Energy Astrophysical Phenomena · Physics 2025-12-02 Marco Padovani , Daniele Galli , Corey T. Plowman , Liam H. Scarlett , Mark C. Zammit , Igor Bray , Dmitry V. Fursa

We have investigated the evaporation of close-in exoplanets irradiated by ionizing photons. We find that the properties of the flow are controlled by the ratio of the recombination time to the flow time-scale. When the recombination…

Earth and Planetary Astrophysics · Physics 2016-01-13 James E. Owen , Marcelo A. Alvarez

To correctly model the abundances of interstellar complex organic molecules (iCOMS) in different environments, both formation and destruction routes should be appropriately accounted for. While several scenarios have been explored for the…

Solar and Stellar Astrophysics · Physics 2019-05-15 Daniela Ascenzi , Andrea Cernuto , Nadia Balucani , Paolo Tosi , Cecilia Ceccarelli , Luca Matteo Martini , Fernando Pirani

Some astrophysical observations of molecular hydrogen point to a broadening of the velocity distribution for molecules at excited rotational levels. This effect is observed in both Galactic and high redshift clouds. Analysis of H_2, HD, and…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-21 S. A. Balashev , D. A. Varshalovich , A. V. Ivanchik

We create a photoionization model embedded in the turbulent ISM by using the state-of-the-art Messenger Monte-Carlo MAPPINGS~V code (M$^3$) in conjunction with the CMFGEN stellar atmosphere model. We show that the turbulent ISM causes the…

Astrophysics of Galaxies · Physics 2022-08-03 Yifei Jin , Lisa J. Kewley , Ralph S. Sutherland

We present three-dimensional astrochemical simulations and synthetic observations of magnetised, turbulent, self-gravitating molecular clouds. We explore various galactic interstellar medium environments, including cosmic-ray ionization…

Astrophysics of Galaxies · Physics 2021-01-20 Thomas G. Bisbas , Jonathan C. Tan , Kei E. I. Tanaka

We use a sample of 47 homogeneous and high sensitivity CO images taken from the Nobeyama and BIMA surveys to demonstrate that, contrary to common belief, a significant number (~40%) of HI-deficient nearby spiral galaxies are also depleted…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Michele Fumagalli , Mark R. Krumholz , J. Xavier Prochaska , Giuseppe Gavazzi , Alessandro Boselli

The aim of this work is to draw attention to the processes of radiative charge exchange in non-symmetric ion-atom collisions as a factor of influence on the opacity of stellar atmospheres in VUV region. For that purpose calculations of the…

Solar and Stellar Astrophysics · Physics 2013-11-05 V. A. Sreckovic , A. A. Mihajlov , Lj. M. Ignjatovic , M. S. Dimitrijevic

We develop a flexible one-dimensional code to model the escape of hydrogen and helium from a hot Jupiter as a result of photoionization from extreme-ultraviolet (EUV) radiation. We include stellar spectrum heating and ionization, radiative…

Earth and Planetary Astrophysics · Physics 2025-11-21 Renata Frelikh , Ruth A. Murray-Clay

We present, for the first time, direct evidence that, in a merger of disk galaxies, the preexisting central metallicities will mix as a result of gas being transported in the merger interface region, along the line that joins the two…

Astrophysics of Galaxies · Physics 2015-06-23 S. Torres-Flores , C. Mendes de Oliveira , P. Amram , M. Alfaro-Cuello , E. R. Carrasco , D. F. de Mello