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Cross-sections for dissociative recombination and electron-impact vibrational excitation of the BF$^+_2$ molecular ion are computed using a theoretical approach that combines the normal modes approximation for the vibrational states of the…

Plasma Physics · Physics 2024-05-03 V. Kokoouline , M. Ayouz , J. Zs. Mezei , K. Hassouni , I. F. Schneider

Transition of an electron from a free to a bound state is critical in determining the qualitative shape of the spectrum in high-order harmonic generation (HHG), and in tomographic imaging of orbitals. We calculate and compare the…

In astronomical environments, the high-temperature emission of plasma mainly depends on ion charge states, which requires accurate analysis of the ionization and recombination processes. For various phenomena involving energetic particles,…

Solar and Stellar Astrophysics · Physics 2025-06-18 Chengcai Shen , Xiaocan Li , Yuan-Kuen Ko , John C. Raymond , Fan Guo , Vanessa Polito , Viviane Pierrard

We present new observations of O II recombination lines in ten bright planetary nebulae, along with spatially-resolved measurements of O II and [O III] in the Ring nebula NGC 6720, to study the discrepancy between abundances derived from O…

Astrophysics · Physics 2007-05-23 D. R. Garnett , H. L. Dinerstein

We present spatially-resolved spectral of O II permitted lines and [O III] forbidden lines in the Ring Nebula NGC 6720. We find significant differences in the spatial distribution of the O II and [O III] lines. The [O III] emission follows…

Astrophysics · Physics 2009-11-06 D. R. Garnett , H. L. Dinerstein

The spatial structure of the emission lines and continuum over the 50 arcsecond extent of the nearby, O-rich, planetary nebula NGC 7009 (Saturn Nebula) have been observed with the MUSE integral field spectrograph on the ESO Very Large…

The level-resolved radiative recombination (RR) rate coefficients for H-like to Na-like ions from H (Z = 1) up to and including Zn (Z = 30) are studied here. For H-like ions, the quantum-mechanical exact photoionization cross sections for…

High Energy Astrophysical Phenomena · Physics 2016-02-24 Junjie Mao , Jelle Kaastra

Relativistically broadened and redshifted 6.4 -- 6.9 keV iron K lines are observed from many accretion powered objects, including X-ray binaries and active galactic nuclei (AGN). Existence of gas close to the central engine implies large…

High Energy Astrophysical Phenomena · Physics 2021-02-24 T. Kallman , M. Bautista , J. Deprince , J. A. Garcia , C. Mendoza , A. Ogorzalek , P. Palmeri , P. Quinet

In the first paper of this series, we study the level population problem of recombining carbon ions. We focus our study on high quantum numbers anticipating observations of Carbon Radio Recombination Lines to be carried out by the LOw…

Astrophysics of Galaxies · Physics 2017-03-22 F. Salgado , L. K. Morabito , J. B. R. Oonk , P. Salas , M. C. Toribio , H. J. A. Rottgering , A. G. G. M. Tielens

Being the backbone element of DNA, phosphorus is a key component in the search for life in the Universe. To aid in its detection, we present line emissivity ratios for the five lowest-lying forbidden [P~II] transitions, namely those among…

Earth and Planetary Astrophysics · Physics 2023-03-01 Kevin Hoy , Sultana N. Nahar , Anil K. Pradhan

Late-time spectra of stripped-envelope CC-SNe are dominated by strong [O {\sc i}] $\lambda\lambda$6300,6363 emission, caused by thermal electron excitation of forbidden [O {\sc i}] transitions. The permitted O {\sc i} 7774 \AA\ line is also…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Immanuel Maurer , Paolo Mazzali

We present Maxwellian-averaged effective collision strengths for the electron-impact excitation of S III over a wide range of electron temperatures of astrophysical importance, log T(K) = 3.0-6.0. The calculation incorporates 53…

Solar and Stellar Astrophysics · Physics 2015-06-16 M. F. R. Grieve , C. A. Ramsbottom , C. E. Hudson , F. P. Keenan

We have obtained deep optical, long-slit spectrophotometry of the Galactic HII regions M 17, NGC 3576 and of the Magellanic Cloud HII regions 30 Doradus, LMC N11B and SMC N66, recording the optical recombination lines (ORLs) of CII, NII and…

Astrophysics · Physics 2009-11-07 Yiannis G. Tsamis , M. J. Barlow , X. -W. Liu , I. J. Danziger , P. J. Storey

Sensitive spectral observations made in two frequency bands near 6.0 and 17.6 GHz are described for Orion and W51. Using frequency switching we were able to achieve a dynamic range in excess of 10,000 without fitting sinusoidal or…

Astrophysics of Galaxies · Physics 2013-01-23 M. B Bell , L. W. Avery , J. M. MacLeod , J. P. Vallee

Thermodynamic quantities of Coulomb plasmas consisting of point-like ions immersed in a compressible, polarizable electron background are calculated for ion charges Z=1 to 26 and for a wide domain of plasma parameters ranging from the…

Plasma Physics · Physics 2016-09-08 G. Chabrier , A. Y. Potekhin

We present the results of 3D particle-in-cell (PIC) simulations that explore relativistic magnetic reconnection in pair plasma with strong synchrotron cooling and a small mass fraction of non-radiating ions. Our results demonstrate that the…

High Energy Astrophysical Phenomena · Physics 2023-10-03 Alexander Chernoglazov , Hayk Hakobyan , Alexander A. Philippov

We aim to present a comprehensive theoretical investigation of dielectronic recombination (DR) of the silicon-like isoelectronic sequence and provide DR and radiative recombination (RR) data that can be used within a generalized…

Atomic Physics · Physics 2018-03-14 Jagjit Kaur , T. W. Gorczyca , N. R. Badnell

We present spectrophotometry of 12 Galactic and 3 Magellanic Cloud planetary nebulae (PNe). Nine of the Galactic PNe were observed by scanning the slit across the PN. We use the fluxes of collisionally excited lines (CELs) to derive…

Astrophysics · Physics 2009-11-07 Y. G. Tsamis , M. J. Barlow , X. -W. Liu , I. J. Danziger , P. J. Storey

Highly excited eigenstates of atoms and ions with open f shell are chaotic superpositions of thousands, or even millions of Hartree-Fock determinant states. The interaction between dielectronic and multielectronic configurations leads to…

Atomic Physics · Physics 2015-06-17 V. A. Dzuba , V. V. Flambaum , G. F. Gribakin , C. Harabati , M. G. Kozlov