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Related papers: CO diffusion and desorption kinetics in CO$_2$ ice…

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Carbon dioxide (CO$_2$) sequestration in saline aquifers has been introduced as one of the most practical, long-term, and safe solutions to tackle a growing threat originating from the emission of CO$_2$. Successfully executing and planning…

Mesoscale and Nanoscale Physics · Physics 2021-09-07 Sina Omrani , Mehdi Ghasemi , Saeed Mahmoodpour , Ali Shafiei , Behzad Rostami

We develop a simple iterative scheme to include vertical turbulent mixing and diffusion in ProDiMo thermo-chemical models for protoplanetary discs. The models are carefully checked for convergence toward the time-independent solution of the…

Earth and Planetary Astrophysics · Physics 2022-12-21 P. Woitke , A. M. Arabhavi , I. Kamp , W. -F. Thi

Context. The dust and gas temperature in proto-planetary disks play critical roles in determining their chemical evolution and influencing planet formation processes. Aims. We attempted an accurate measurement of the dust and CO temperature…

The typical amount of molecular hydrogen (${\rm H_2}$) in interstellar ices is not known, but significant freeze-out of ${\rm H_2}$ on dust grains is not expected. However, chemical models ubiquitously predict large amounts of $\rm H_2$…

Astrophysics of Galaxies · Physics 2025-07-03 O. Sipilä , K. Silsbee , N. Carbajal , P. Caselli , M. Padovani

Laboratory results of the optical properties of vapor-deposited water ice, specifically the refractive index and extinction coefficient, are available mainly for a selective set of wavelengths and a limited number of deposition…

Instrumentation and Methods for Astrophysics · Physics 2022-02-09 Jiao He , Sharon J. M. Diamant , Siyu Wang , Haochuan Yu , Will R. M. Rocha , Marina Rachid , Harold Linnartz

We investigate the bright CO fundamental emission in the central regions of five protostars in their primary mass assembly phase using new observations from JWST's Near-Infrared Spectrograph (NIRSpec) and Mid-Infrared Instrument (MIRI). CO…

We measured the binding energy of N$_2$, CO, O$_2$, CH$_4$, and CO$_2$ on non-porous (compact) amorphous solid water (np-ASW), of N$_2$ and CO on porous amorphous solid water (p-ASW), and of NH$_3$ on crystalline water ice. We were able to…

Instrumentation and Methods for Astrophysics · Physics 2016-07-13 Jiao He , Kinsuk Acharyya , Gianfranco Vidali

N131 is a typical infrared dust bubble showing an expanding ringlike shell. We study what kinds of CO line ratios can be used to trace the interaction in the expanding bubble. We carry out new $\rm CO\,(3-2)$ observations towards bubble…

Astrophysics of Galaxies · Physics 2019-11-06 Chuan-Peng Zhang , Guang-Xing Li , Chenlin Zhou , Lixia Yuan , Ming Zhu

The abundance of H2 in molecular clouds, relative to the commonly used tracer CO, has only been measured toward a few embedded stars, which may be surrounded by atypical gas. We present observations of near-infrared absorption by H2, CO,…

Astrophysics of Galaxies · Physics 2017-03-30 John H. Lacy , Christopher Sneden , Hwihyun Kim , Daniel T. Jaffe

CO is the most widely used gas tracer of protoplanetary disks. Its abundance is usually assumed to be an interstellar ratio throughout the warm molecular layer of the disk. But recent observations of low CO gas abundance in many…

Earth and Planetary Astrophysics · Physics 2019-10-02 Ke Zhang , Edwin A. Bergin , Kamber R. Schwarz , Sebastiaan Krijt , Fred Ciesla

Using IRAM 30m, SEST 15m, and Nancay radiotelescopes, we have gathered the 1mm continuum emission, spectra of the J=1--0 CO line and of the HI line at 21cm for two samples of IRAS galaxies. Using these data, we have estimated the HI masses,…

Astrophysics · Physics 2016-08-30 Paola Andreani , Fabienne Casoli , Maryvonne Gerin

The astronomical gas-phase detection of simple species and small organic molecules in cold pre-stellar cores, with abundances as high as $\sim$$10^{-8}-10^{-9}$ n$_\text{H}$, contradicts the generally accepted idea that at $10$ K, such…

Astrophysics of Galaxies · Physics 2018-06-19 K-J Chuang , G Fedoseev , D Qasim , S Ioppolo , EF van Dishoeck , H Linnartz

The adsorption of $CO_2$ on the $Fe_3$$O_4$(001)-($\sqrt{2}$ $\times$ $\sqrt{2}$)R45{\deg} surface was studied experimentally using temperature programmed desorption (TPD), electron spectroscopies (UPS and XPS), and scanning tunneling…

Ultraviolet (UV) photodissociation of CO controls the abundances and distribution of CO and its photodissociation products. This significantly influences the gas-phase chemistry in the circumstellar envelope (CSE) around evolved stars. A…

Solar and Stellar Astrophysics · Physics 2019-05-22 Maryam Saberi , Wouter Vlemmings , Elvire De Beck

Ice-coated dust grains provide the main reservoir of volatiles that play an important role in planet formation processes and may become incorporated into planetary atmospheres. However, due to observational challenges, the ice abundance…

Dust grains in cold circumstellar regions and dark-cloud interiors at 10-20 K are covered by ice mantles. A nonthermal desorption mechanism is invoked to explain the presence of gas-phase molecules in these environments, such as the…

Solar and Stellar Astrophysics · Physics 2014-06-02 G. A. Cruz-Diaz , G. M. Muñoz Caro , Y. -J. Chen , T. -S. Yih

We have investigated the thermally induced proton/deuteron exchange in mixed amorphous H$_2$O:D$_2$O ices by monitoring the change in intensity of characteristic vibrational bending modes of H$_2$O, HDO, and D$_2$O with time and as function…

Astrophysics of Galaxies · Physics 2015-06-23 Thanja Lamberts , Sergio Ioppolo , Herma Cuppen , Gleb Fedoseev , Harold Linnartz

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 study the emission and absorption of CO ro-vibrational lines in the spectra of intermediate mass pre-main-sequence stars with the aim to determine both the spatial distribution of the CO gas and its physical properties. We also aim to…

Solar and Stellar Astrophysics · Physics 2015-01-28 G. van der Plas , M. E. van den Ancker , L. B. F. M. Waters , C. Dominik

CO gas emission is a fundamental tool for measuring column density, but in cold, dark clouds, much of the CO is locked away in ice. We present JWST results from observations of a star forming filament (G0.342+0.024) that that appears to be…