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The Diffuse Ionised Gas (DIG) in galaxies traces photoionisation feedback from massive stars. Through three dimensional photoionisation simulations, we study the propagation of ionising photons, photoionisation heating and the resulting…

Astrophysics of Galaxies · Physics 2015-06-19 J. E. Barnes , Kenneth Wood , Alex S. Hill , L. M. Haffner

We suggest that three-body chemistry may occur in warm high density gas evaporating in transient co\textendash desorption events on interstellar ices. Using a highly idealised computational model we explore the chemical conversion from…

Astrophysics of Galaxies · Physics 2015-05-20 Cesare Cecchi-Pestellini , Jonathan M. C. Rawlings , Serena Viti , David A. Williams

Context. The presence of dust in the interstellar medium has profound consequences on the chemical composition of regions where stars are forming. Recent observations show that many species formed onto dust are populating the gas phase,…

Solar and Stellar Astrophysics · Physics 2015-12-16 M. Minissale , F. Dulieu , S. Cazaux , S. Hocuk

We perform the first measurement of the thermal and ionization state of the intergalactic medium (IGM) across 0.9 < z < 1.5 using 301 \lya absorption lines fitted from 12 HST STIS quasar spectra, with a total pathlength of \Delta z=2.1. We…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-06 Teng Hu , Vikram Khaire , Joseph F. Hennawi , Todd M. Tripp , Jose Oñorbe , Michael Walther , Zarija Lukic

This work aims to study the unexplained sulfur depletion observed toward dense clouds and protostars. We made simulation experiments of the UV-photoprocessing and sublimation of H2S and H2S:H2O ice in dense clouds and circumstellar regions,…

Earth and Planetary Astrophysics · Physics 2015-06-03 A. Jiménez-Escobar , G. M. Muñoz Caro

Currently ~36 different absorption bands have been detected in the infrared spectra of cold, dense interstellar and circumstellar environments. These are attributed to the vibrational transitions of ~17 different molecules frozen on dust…

Astrophysics · Physics 2007-05-23 A. C. A. Boogert , P. Ehrenfreund

Context. The level of porosity of interstellar ices - largely comprised of amorphous solid water (ASW) - contains clues on the trapping capacity of other volatile species and determines the surface accessibility that is needed for solid…

Solar and Stellar Astrophysics · Physics 2014-12-10 S. Cazaux , J. -B. Bossa , H. Linnartz , A. G. G. M. Tielens

Circumstellar disks are exposed to intense ultraviolet radiation from the young star. In the inner disks, the UV radiation can be enhanced by more than seven orders of magnitude compared with the average interstellar field, resulting in a…

Astrophysics · Physics 2009-07-30 E. F. van Dishoeck , B. Jonkheid , M. C. van Hemert

Interstellar ices play a fundamental role in the physical and chemical evolution of molecular clouds and star-forming regions, yet their large-scale distribution and abundance remain challenging to map. In this work, I present the ice color…

Astrophysics of Galaxies · Physics 2025-10-15 Stefan Meingast

We present a technique to treat systems with very many levels, like molecules, in non-LTE. This method is based on a superlevel formalism coupled with rate operator splitting. Superlevels consist of many individual levels that are assumed…

Astrophysics · Physics 2009-10-31 Andreas Schweitzer , Peter H. Hauschildt , E. Baron

The detection of various molecular species, including complex organic molecules relevant to biochemical and geochemical processes, in astronomical settings such as the interstellar medium or the outer Solar System has led to the increased…

Instrumentation and Methods for Astrophysics · Physics 2024-11-19 R. Rácz , S. T. S. Kovács , G. Lakatos , K. K. Rahul , D. V. Mifsud , P. Herczku , B. Sulik , Z. Juhász , Z. Perduk , S. Ioppolo , N. J. Mason , T. A. Field , S. Biri , R. W. McCullough

Up to 90% of the chemical reactions during star formation occurs on ice surfaces, probably including the formation of complex organics. Only the most abundant ice species are however observed directly by infrared spectroscopy. This study…

Solar and Stellar Astrophysics · Physics 2015-05-13 Karin I. Oberg , Sandrine Bottinelli , Ewine F. van Dishoeck

We present a series of 2-d ($r,\phi$) hydrodynamic simulations of marginally self gravitating disks around protostars using an SPH code. We implement simple dynamical heating and we cool each location as a black body, using a photosphere…

Astrophysics · Physics 2011-02-11 Andrew F. Nelson , Willy Benz , Tamara Ruzmaikina

We demonstrate the production of ultracold polar RbCs molecules in their vibronic ground state, via photoassociation of laser-cooled atoms followed by a laser-stimulated state transfer process. The resulting sample of $X ^1\Sigma^+ (v=0)$…

Atomic Physics · Physics 2009-11-11 J. M. Sage , S. Sainis , T. Bergeman , D. DeMille

Ice-templating is a well-established processing route for porous ceramics. Because of the structure/properties relationships, it is essential to better understand and control the solidification microstructures. Ice-templating is based on…

Soft Condensed Matter · Physics 2017-12-22 Dmytro Dedovets , Sylvain Deville

We present a novel framework to self-consistently model the effects of radiation fields, dust physics and molecular chemistry (H$_2$) in the interstellar medium (ISM) of galaxies. The model combines a state-of-the-art radiation…

Complex organic molecules (COMs) can be produced by energetic processing of interstellar ice mantles accreted on top of dust grains. Two COMs with proposed energetic ice formation pathways are formamide and acetaldehyde. Both have been…

Solar and Stellar Astrophysics · Physics 2020-05-20 Rafael Martin-Domenech , Karin I. Oberg , Mahesh Rajappan

In this work we present a new hybrid method to simulate the thermal effects of the reionization in cosmological hydrodynamical simulations. The method improves upon the standard approach used in simulations of the intergalactic medium (IGM)…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-11 Jose Oñorbe , F. B. Davies , Z. Lukić , J. F. Hennawi , D. Sorini

Methanol and formaldehyde are two simple organic molecules that are ubiquitously detected in the interstellar medium. An origin in the solid phase and a subsequent nonthermal desorption into the gas phase is often invoked to explain their…

Astrophysics of Galaxies · Physics 2016-04-20 R. Martín-Doménech , G. M. Muñoz Caro , G. A. Cruz-Díaz

Under cold conditions in dense cores, gas-phase molecules and atoms are depleted from the gas-phase to the surface of interstellar grains. Considering the time scales and physical conditions within these cores, a portion of these molecules…

Astrophysics of Galaxies · Physics 2021-08-11 V. Wakelam , E. Dartois , M. Chabot , S. Spezzano , D. Navarro-Almaida , J. -C. Loison , A. Fuente