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Hydrogenated amorphous carbon (a-C:H) has been proposed as one of the carbonaceous solids detected in the interstellar medium. Energetic processing of the a-C:H particles leads to the dissociation of the C-H bonds and the formation of…

Earth and Planetary Astrophysics · Physics 2016-06-22 Rafael Martín-Doménech , Emmanuel Dartois , Guillermo M. Muñoz Caro

The ULIRG Mrk 231 exhibits very strong water rotational lines between \lambda = 200-670\mu m, comparable to the strength of the CO rotational lines. High redshift quasars also show similar CO and H2O line properties, while starburst…

Astrophysics of Galaxies · Physics 2015-06-03 R. Meijerink , S. Cazaux , M. Spaans

We present results from three-dimensional hydrodynamic simulations of the high redshift collapse of pregalactic clouds including feedback effects from a soft H2 photodissociating UV radiation field. The simulations use an Eulerian adaptive…

Astrophysics · Physics 2009-10-31 Marie E. Machacek , Greg L. Bryan , Tom Abel

Chloronium (H$_2$Cl$^+$) is an important intermediate of Cl-chemistry in space. The accurate knowledge of its collisional properties allows a better interpretation of the corresponding observations in interstellar clouds and therefore a…

Chemical Physics · Physics 2024-12-31 Sándor Demes , Dariusz Kędziera , Alexandre Faure , François Lique

We study a fragment of a large quiescent filament observed on May 29, 2017 by the Interferometric BIdimensional Spectropolarimeter (IBIS) mounted at the Dunn Solar Telescope. We focus on its quiescent stage prior to its eruption. We analyse…

Solar and Stellar Astrophysics · Physics 2019-11-13 P. Schwartz , S. Gunar , J. M. Jenkins , D. M. Long , P. Heinzel , D. P. Choudhary

The first JWST observations of TRAPPIST-1 c showed a secondary eclipse depth of 421+/-94 ppm at 15 um, which is consistent with a bare rock surface or a thin, O2-dominated, low CO2 atmosphere (Zieba et al. 2023). Here, we further explore…

We introduce a sub-grid model for the non-equilibrium abundance of molecular hydrogen in cosmological simulations of galaxy formation. We improve upon previous work by accounting for the unresolved structure of molecular clouds in a…

Astrophysics of Galaxies · Physics 2015-06-19 Matteo Tomassetti , Cristiano Porciani , Emilio Romano-Diaz , Aaron D. Ludlow

We propose a classification of exoplanet atmospheres based on their H, C, O, N element abundances below about 600 K. Chemical equilibrium models were run for all combinations of H, C, N, O abundances, and three types of solutions were…

Earth and Planetary Astrophysics · Physics 2021-02-10 P. Woitke , O. Herbort , Ch. Helling , E. Stüeken , M. Dominik , P. Barth , D. Samra

Atomic hydrogen loss at the top of HD 209458b's atmosphere has been recently detected Vidal-Madjar et al. 2003. We have developed a 1-dimensional model to study the chemistry in the upper atmosphere of this extrasolar "hot jupiter". The 3…

Astrophysics · Physics 2009-11-10 Mao-Chang Liang , Christopher D. Parkinson , Anthony Y. -T. Lee , Yuk L. Yung

Light-matter interactions lie at the heart of our exploration of exoplanetary atmospheres. Interpreting data obtained by remote sensing is enabled by meticulous, time- and resource-consuming work aiming at deepening our understanding of…

Earth and Planetary Astrophysics · Physics 2025-03-06 Laurent Wiesenfeld , Prajwal Niraula , Julien de Wit , Nejmeddine Jaïdane , Iouli E. Gordon , Robert J. Hargreaves

The hydrogen abstraction reaction between H and H$_2$S, yielding HS and H$_2$ as products, has been studied within the framework of interstellar surface chemistry. High-temperature rate constants up to 2000 K are calculated in the gas phase…

Astrophysics of Galaxies · Physics 2017-12-07 Thanja Lamberts , Johannes Kästner

The existence of substellar cold H2 globules in planetary nebulae and the mere existence of comets suggest that the physics of cold interstellar gas might be much richer than usually envisioned. We study the case of a cold gaseous medium in…

Astrophysics of Galaxies · Physics 2016-08-08 Andreas Füglistaler , Daniel Pfenniger

Ultra-hot Jupiters have recently attracted interest from observers and theoreticians alike, as they provide observationally accessible test cases. We apply a hierarchical modelling approach as a virtual laboratory to study cloud formation…

Earth and Planetary Astrophysics · Physics 2020-01-08 Ch. Helling , N. Iro , L. Corrales , D. Samra , K. Ohno , M. K. Alam , M. Steinrueck , B. Lew , K. Molaverdikhani , R. J MacDonald , O. Herbort , P. Woitke , V. Parmentier

The TRAPPIST-1 system provides an extraordinary opportunity to study multiple terrestrial extrasolar planets and their atmospheres. Here we use the National Center for Atmospheric Research Community Atmosphere Model version 4 to study the…

Earth and Planetary Astrophysics · Physics 2018-04-03 Eric T. Wolf

We show that collision-induced absorption allows molecular hydrogen to act as an incondensible greenhouse gas, and that bars or tens of bars of primordial H2-He mixtures can maintain surface temperatures above the freezing point of water…

Earth and Planetary Astrophysics · Physics 2015-05-28 Raymond Pierrehumbert , Eric Gaidos

The detections of atomic hydrogen, heavy atoms and ions surrounding the extrasolar giant planet (EGP) HD209458b constrain the composition, temperature and density profiles in its upper atmosphere. Thus the observations provide guidance for…

Earth and Planetary Astrophysics · Physics 2015-06-11 T. T. Koskinen , M. J. Harris , R. V. Yelle , P. Lavvas

Understanding the surface temperature and interior structure of cold-to-temperate sub-Neptunes is critical for assessing their habitability, yet direct observations are challenging. In this study, we investigate the impact of water…

Earth and Planetary Astrophysics · Physics 2024-09-05 Ziyu Huang , Xinting Yu , Shang-Min Tsai , Julianne I. Moses , Kazumasa Ohno , Joshua Krissansen-Totton , Xi Zhang , Jonathan Fortney

The atmospheric characterisation of temperate exoplanets is becoming accessible with JWST, providing a critical connection between Solar System planets and the more commonly observed hot-Jupiters. K2-18 b, a temperate sub-Neptune orbiting…

Earth and Planetary Astrophysics · Physics 2026-05-27 P. Lavvas , R. Liu , G. Tinetti , S. Paraskevaidou , P. Drossart , A. Coustenis

Understanding the deep atmospheric composition of Jupiter provides critical constraints on its formation and the chemical evolution of the solar nebula. In this study, we combine one-dimensional thermochemical kinetic-transport modeling…

Earth and Planetary Astrophysics · Physics 2025-12-09 Jeehyun Yang , Ali Hyder , Renyu Hu , Jonathan I. Lunine

We constrain Europa's tenuous atmosphere on the subsolar hemisphere by combining two sets of observations: oxygen emissions at 1304 {\AA} and 1356 {\AA} from Hubble Space Telescope (HST) spectral images, and Galileo magnetic field…

Space Physics · Physics 2022-11-16 Sebastian Cervantes , Joachim Saur