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Context. Millimetric observations have measured high degrees of molecular deuteration in several species seen around low-mass protostars. The Herschel Space Telescope, launched in 2009, is now providing new measures of the deuterium…

The formation of water molecules from the reaction between ozone (O3) and D-atoms is studied experimentally for the first time. Ozone is deposited on non-porous amorphous solid water ice (H2O), and D-atoms are then sent onto the sample held…

Astrophysics of Galaxies · Physics 2015-05-13 H. Mokrane , H. Chaabouni , M. Accolla , E. Congiu , F. Dulieu , M. Chehrouri , J. L. Lemaire

We carry out Monte-Carlo simulation to study deuterium enrichment of interstellar grain mantles under various physical conditions. Based on the physical properties, various types of clouds are considered. We find that in diffuse cloud…

Astrophysics of Galaxies · Physics 2015-10-06 Ankan Das , Dipen Sahu , Liton Majumdar , Sandip K. Chakrabarti

We analyze recently-measured total reaction cross sections for 24-38Mg isotopes incident on 12C targets at 240 MeV/nucleon by using the folding model and antisymmetrized molecular dynamics(AMD). The folding model well reproduces the…

Deuterium enhancement of monodeuterated species has been recognized for more than 30 years as a result of the chemical fractionation that results from the difference in zero point energies of deuterated and hydrogenated molecules. The key…

Astrophysics · Physics 2009-11-11 Charlotte Vastel , T. G. Phillips , P. Caselli , C. Ceccarelli , L. Pagani

High-mass stars are expected to form from dense prestellar cores. Their precise formation conditions are widely discussed, including their virial condition, which results in slow collapse for super-virial cores with strong support by…

Astrophysics of Galaxies · Physics 2017-06-21 Bastian Körtgen , Stefano Bovino , Dominik R. G. Schleicher , Andrea Giannetti , Robi Banerjee

We study collisions between neutral, deuterated ammonia molecules (ND$_3$) stored in a 50 cm diameter synchrotron and argon atoms in co-propagating supersonic beams. The advantages of using a synchrotron in collision studies are twofold:…

Tritium permeation into and through materials poses a critical challenge for the development of nuclear fusion reactors. Minimizing tritium permeation is essential for the safe and efficient use of available fuel supplies. In this work, we…

Context. The deuterium fraction in low-mass prestellar cores is a good diagnostic indicator of the initial phases of star formations, and it is also a fundamental quantity to infer the ionisation degree in these objects. Aims. With the…

Solar and Stellar Astrophysics · Physics 2019-08-28 Elena Redaelli , Luca Bizzocchi , Paola Caselli , Olli Sipilä , Valerio Lattanzi , Barbara Michela Giuliano , Silvia Spezzano

We present N2D+ 3-2 (IRAM) and H2D+ 1_11 - 1_10 and N2H+ 4-3 (JCMT) maps of the small cluster-forming Ophiuchus B2 core in the nearby Ophiuchus molecular cloud. In conjunction with previously published N2H+ 1-0 observations, the N2D+ data…

Astrophysics of Galaxies · Physics 2015-05-19 R. K. Friesen , J. Di Francesco , P. C. Myers , A. Belloche , Y. L. Shirley , T. L. Bourke , P. André

New interlayer intermolecular potential model was proposed and it represented ``ABAB'' staking of graphite. Hydrogen atom sputtering on graphite surface was investigated using molecular dynamics simulation. In the initial short time period,…

Materials Science · Physics 2007-11-26 Atsushi Ito , Hiroaki Nakamura

Seven rotational and fine-structure transitions of the deuterated molecular ion SD+ in the X 3S- ground electronic state have been measured in the 271-863 GHz region in the laboratory. This ion has been produced by DC-glow discharge using a…

Astrophysics of Galaxies · Physics 2024-03-25 Mitsunori Araki , Valerio Lattanzi , Christian P. Endres , Paula Caselli

Radioastronomical observations have recently discovered PAHs of moderate size (up to 24 carbon atoms) in cold dark clouds, although it is currently unknown whether they are formed in situ through a bottom-up mechanism or from larger PAHs…

The dissociation of hydrogen molecules on the \gamma-U(100) surface is systematically studied with the density functional theory method. Through potential energy surface calculations, we find that hydrogen molecules can dissociate without…

Materials Science · Physics 2011-10-27 Yu Yang , Ping Zhang , Peng Shi , Xiaolin Wang

Nickel vapor-deposited on the SrTiO$_3$(110) surface was studied using scanning tunneling microscopy, photoemission spectroscopy (PES), and density functional theory calculations. This surface forms a (4 $\times$ 1) reconstruction, composed…

We determine the relative ionization of deuterium and hydrogen in low metallicity damped Lyman-alpha (DLA) and sub-DLA systems using a detailed suite of photoionization simulations. We model metal-poor DLAs as clouds of gas in pressure…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-15 Ryan Cooke , Max Pettini

Formamide (NH2CHO) and methylamine (CH3NH2) are known to be the most abundant amine-containing molecules in many astrophysical environments. The presence of these molecules in the gas phase may result from thermal desorption of interstellar…

Astrophysics of Galaxies · Physics 2018-05-02 Henda Chaabouni , Stephan Diana , Thanh Nguyen , François Dulieu

There is only a handful of scanning techniques that can provide surface topography at nanometre resolution. At the same time, there are no methods that are capable of non-invasive imaging of the three-dimensional surface topography of a…

Instrumentation and Detectors · Physics 2017-03-07 Tatiana Latychevskaia , Wei-Hao Hsu , Wei-Tse Chang , Chun-Yueh Lin , Ing-Shouh Hwang

We present the results of formaldehyde and methanol deuteration measurements towards the Class I low-mass protostar SVS13-A, in the framework of the IRAM 30-m ASAI (Astrochemical Surveys At IRAM) project. We detected emission lines of…

Solar and Stellar Astrophysics · Physics 2017-03-22 E. Bianchi , C. Codella , C. Ceccarelli , F. Fontani , L. Testi , R. Bachiller , B. Lefloch , L. Podio , V. Taquet

Deuterated methanol is one of the most robust windows astrochemists have on the individual chemical reactions forming deuterium-bearing molecules and the physicochemical history of the regions where they reside. The first-time detection of…