English
Related papers

Related papers: Molecular photodissociation

200 papers

The physical and chemical conditions in photodissociation regions (PDRs) are largely determined by the influence of far ultraviolet radiation. Far-UV photons can efficiently dissociate molecular hydrogen, a process that must be balanced at…

Astrophysics of Galaxies · Physics 2018-06-08 P. Castellanos , A. Candian , H. Andrews , A. G. G. M. Tielens

UV-induced photodesorption of ice is a non-thermal evaporation process that can explain the presence of cold molecular gas in a range of interstellar regions. Information on the average UV photodesorption yield of astrophysically important…

We present high-resolution spectroscopy and images of a photodissociation region (PDR) in M16 obtained during commissioning of NIRSPEC on the Keck II telescope. PDRs play a significant role in regulating star formation, and M16 offers the…

Some astrophysical observations of molecular hydrogen point to a broadening of the velocity distribution for molecules at excited rotational levels. This effect is observed in both Galactic and high redshift clouds. Analysis of H_2, HD, and…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-21 S. A. Balashev , D. A. Varshalovich , A. V. Ivanchik

In the interstellar medium, cosmic rays (CRs) generate a field of ultraviolet (UV) photons via the excitation and subsequent radiative decay of $\rm H_2$ molecules. This UV field is a major agent of ionization and dissociation in the inner…

Astrophysics of Galaxies · Physics 2026-01-15 O. Sipilä , P. Caselli , M. Padovani , D. Galli , T. Grassi , H. R. Hrodmarsson , S. S. Jensen , E. Roueff

The photodissociation of the HD+ molecular ion in intense short- pulsed linearly polarized laser fields is studied using a time- dependent wave-packet approach where molecular rotation is fully included. We show that applying a coherent…

chem-ph · Physics 2019-04-04 Eric Charron , Annick Giusti-Suzor , Frederick Mies

We demonstrate detection of NaRb Feshbach molecules at high magnetic field by combining molecular photodissociation and absorption imaging of the photofragments. The photodissociation process is carried out via a spectroscopically selected…

Atomic Physics · Physics 2020-12-02 Fan Jia , Zhichao Guo , Lintao Li , Dajun Wang

Benzene molecules, present in the proto-planetary nebula CRL 618, are ionized and dissociated by UV and X-ray photons originated from the hot central star and by its fast wind. Ionic species and free radicals produced by these processes can…

Astrophysics · Physics 2009-11-13 H. M. Boechat-Roberty , R. Neves , S. Pilling , A. F. Lago , G. G. B. de Souza

Accurate photodissociation cross sections have been computed for transitions from the X $^1\Sigma^+$ ground electronic state of CS to six low-lying excited electronic states. New ab initio potential curves and transition dipole moment…

Photochemical heating is analyzed with emphasis on the heating generated by chemical reactions initiated by the products of photodissociation and photoionization. The immediate products are slowed down by collisions with the ambient gas and…

Solar and Stellar Astrophysics · Physics 2015-10-21 A. E. Glassgold , J. R. Najita

Molecular clouds (MCs) are the birthplaces of new stars in galaxies. A key component of MCs are photodissociation regions (PDRs), where far-ultraviolet radiation plays a crucial role in determining the gas's physical and chemical state.…

We present results of classical dynamics calculations, performed to study the photodissociation of water in crystalline and amorphous ice surfaces at a surface temperature of 10 K. Dissociation in the top six monolayers is considered.…

Astrophysics · Physics 2009-11-11 Stefan Andersson , Ayman Al-Halabi , Geert-Jan Kroes , Ewine F. van Dishoeck

The photodissociation cross section of the molecular ion HeH$^+$ was calculated within the Born-Oppenheimer approximation for a parallel, a perpendicular, and an isotropic orientation of the molecular axis with respect to the field,…

Atomic Physics · Physics 2015-05-13 Irina Dumitriu , Alejandro Saenz

Far-ultraviolet photons from OB-type massive stars regulate the heating, ionization, and chemistry of much of the neutral interstellar gas in star-forming galaxies. The interaction of FUV radiation and interstellar matter takes place in…

Astrophysics of Galaxies · Physics 2022-09-21 Javier R. Goicoechea , Sara Cuadrado , Franck Le Petit

The system of CH$_3$I adsorbed on submonolayer, monolayer and multilayer thin films of D$_2$O on Cu(110) has been studied by measuring the time-of-flight (TOF) distributions of the desorbing CH$_3$ fragments after photodissociation using…

Chemical Physics · Physics 2021-01-18 E. R. Miller , G. D. Muirhead , E. T. Jensen

The evaporation of water is ubiquitous in nature and industrial technologies. The known mechanism for evaporation is "thermal evaporation" which highlights the energy input for evaporation is via heat. Due to the weak absorption of water to…

Atomic and Molecular Clusters · Physics 2024-04-24 Yaodong Tu , Gang Chen

Soft x-ray radiation from the sun is responsible for the production of high energy photoelectrons in the D and E regions of the ionosphere, where they deposit most of their ionization energy. The photoelectrons created by this process are…

Chemical Physics · Physics 2022-11-21 Srimoyee Samaddar , Karthik Venkataramani , Justin Yonker , Scott. M. Bailey

Phenomena involving electron transfer are ubiquitous in nature, photosynthesis and enzymes or protein activity being prominent examples. Their deep understanding thus represents a mandatory scientific goal. Moreover, controlling the…

Chemical Physics · Physics 2017-12-01 Carlo Andrea Rozzi , Filippo Troiani , Ivano Tavernelli

Molecular dynamics calculations have been performed to study the ultraviolet photodissociation of D2O in an amorphous D2O ice surface at 10-90 K, in order to investigate the influence of isotope effects on the photodesorption processes. As…

Chemical Physics · Physics 2011-05-06 C. Arasa , S. Andersson , H. M. Cuppen , E. F. van Dishoeck , G. J. Kroes

Planet-forming disc evolution is not independent of the star formation and feedback process in giant molecular clouds. In particular, OB stars emit UV radiation that heats and disperses discs in a process called 'external photoevaporation'.…

Earth and Planetary Astrophysics · Physics 2022-10-06 Andrew J. Winter , Thomas J. Haworth