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Related papers: Water Ice Deposition and Growth in Molecular Cloud…

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(abridged) Our project endeavors to obtain a robust view of multiplicity among embedded Class I and Flat Spectrum protostars in a wide array of nearby molecular clouds to disentangle ``universal'' from cloud-dependent processes. We have…

Astrophysics · Physics 2008-11-26 G. Duchêne , S. Bontemps , J. Bouvier , P. André , A. A. Djupvik , A. M. Ghez

It has been implicitly assumed that ices on grains in molecular clouds and proto planetary disks are formed by homogeneous layers regardless of their composition or crystallinity. To verify this assumption, we observed the H2O deposition…

Water is a crucial molecule in molecular astrophysics as it controls much of the gas/grain chemistry, including the formation and evolution of more complex organic molecules in ices. Pre-stellar cores provide the original reservoir of…

Starless molecular cores are natural laboratories for interstellar molecular chemistry research. The chemistry of ices in such objects was investigated with a three-phase (gas, surface, and mantle) model. We considered the center part of…

Astrophysics of Galaxies · Physics 2015-04-24 Juris Kalvans

We construct a new set of self-consistent analytical disk models by taking into account both viscous and radiative sources of thermal energy. We analyze the non-isothermal structure of the disk across the mid-plane for optically thick…

Astrophysics · Physics 2008-11-26 Pascale Garaud , Douglas N. C. Lin

One of the major obstacles to accurately model the interstellar chemistry is an inadequate knowledge about the binding energy (BE) of interstellar species with dust grains. In denser region of molecular cloud, where very complex chemistry…

Astrophysics of Galaxies · Physics 2018-07-25 Ankan Das , Milan Sil , Prasanta Gorai , Sandip K. Chakrabarti , Jean-Christophe Loison

Context. Interstellar ice is the main form of metal species in dark molecular clouds. Experiments and observations have shown that the ice is significantly processed after the freeze-out of molecules onto grains. The processing is caused by…

Astrophysics of Galaxies · Physics 2013-06-14 Juris Kalvāns , Ivar Shmeld

Maps of estimated dust column density in molecular clouds are usually assumed to reliably trace the total gas column density structure. In this work we present results showing a clear discrepancy between the dust and the gas distribution in…

We construct detailed vertical structure models of irradiated accretion disks around T Tauri stars with interstellar medium dust uniformly mixed with gas. The dependence of the structure and emission properties on mass accretion rate,…

Astrophysics · Physics 2009-10-31 Paola D'Alessio , Nuria Calvet , Lee Hartmann , Susana Lizano , Jorge Canto

We investigated the behavior of H$_2$, main constituent of the gas phase in dense clouds, after collision with amorphous solid water (ASW) surfaces, one of the most abundant chemical species of interstellar ices. We developed a general…

Chemical Physics · Physics 2020-03-20 G. Molpeceres , J. Kästner

We argue that impact velocities between dust grains with sizes less than $\sim 0.1$ $\mu m$ in molecular cloud cores are dominated by drift arising from ambipolar diffusion. This effect is due to the size dependence of the dust coupling to…

Astrophysics of Galaxies · Physics 2020-09-30 Kedron Silsbee , Alexei Ivlev , Paola Caselli , Olli Sipila , Bo Zhao

We measure the parsec-scale relationship between integrated CO intensity (I_CO) and visual extinction (A_V) in 24 local molecular clouds using maps of CO emission and dust optical depth from Planck. This relationship informs our…

Aims: Our aim is to determine the critical parameters in water chemistry and the contribution of water to the oxygen budget by observing and modelling water gas and ice for a sample of eleven low-mass protostars, for which both forms of…

Astrophysics of Galaxies · Physics 2014-12-03 M. Schmalzl , R. Visser , C. Walsh , T. Albertsson , E. F. van Dishoeck , L. E. Kristensen , J. C. Mottram

We study infrared emission of 17 isolated, diffuse clouds with masses of order solar masses, to test the hypothesis that grain property variations cause the apparently low gas-to-dust ratios that have been measured in those clouds. Maps of…

Astrophysics of Galaxies · Physics 2018-08-13 William T. Reach , Jean-Philippe Bernard , Thomas Jarrett , Carl Heiles

For aspherical interstellar dust grains aligned with their short axes preferentially parallel to the local magnetic field, the amount of extinction per grain is larger when the magnetic field is along the line of sight and smaller when in…

Astrophysics of Galaxies · Physics 2024-11-27 Brandon S. Hensley

We present a systematic analysis of scale-dependent properties of filamentary structures in seven nearby molecular clouds $-$ Taurus, Ophiuchus, Perseus, Orion A, California, IC 5146, Vela C $-$ using the multiscale extraction method…

Astrophysics of Galaxies · Physics 2026-05-06 Guo-Yin Zhang , Alexander Men'shchikov , Jin-Zeng Li

The nuclear-spin chemistry of interstellar water is investigated using the University of Grenoble Alpes Astrochemical Network (UGAN). This network includes reactions involving the different nuclear-spin states of the hydrides of carbon,…

Astrophysics of Galaxies · Physics 2022-01-07 A. Faure , P. Hily-Blant , C. Rist , G. Pineau des Forêts , A. Matthews , D. R. Flower

Single-dish spectra and interferometric maps of (sub)mm lines of H2O-18 and HDO are used to study the chemistry of water in eight regions of high-mass star formation. The spectra indicate HDO excitation temperatures of ~110 K and column…

Astrophysics · Physics 2009-11-11 Floris van der Tak , Malcolm Walmsley , Fabrice Herpin , Cecilia Ceccarelli

AA Tau, a classical T Tauri star in the Taurus cloud, has been the subject of intensive photometric monitoring for more than two decades due to its quasi-cyclic variation in optical brightness. Beginning in 2011, AA Tau showed another…

Solar and Stellar Astrophysics · Physics 2015-05-27 Ke Zhang , Nathan Crockett , Colette Salyk , Klaus Pontoppidan , Neal J. Turner , John M. Carpenter , Geoffrey A. Blake

Water is essential to our understanding of the planet-formation process and habitability on Earth. Although trace amounts of water are seen across all phases of star and planet formation, the bulk of the water reservoir often goes…

Earth and Planetary Astrophysics · Physics 2025-10-24 Margot Leemker , John J. Tobin , Stefano Facchini , Pietro Curone , Alice S. Booth , Kenji Furuya , Merel L. R. van 't Hoff