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Related papers: Atomic data and the density structures of planetar…

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A review of some of the papers that discuss the relevance of the temperature structure present in H II regions and planetary nebulae is presented. Particular attention is given to the determination of the chemical abundances of these…

Astrophysics of Galaxies · Physics 2019-05-08 Manuel Peimbert

The increasing richness of data related to cold dense matter, from laboratory experiments to neutron-star observations, requires a framework for constraining the properties of such matter that makes use of all relevant information. Here, we…

High Energy Astrophysical Phenomena · Physics 2020-01-08 M. Coleman Miller , Cecilia Chirenti , Frederick K. Lamb

Optical integral-field spectroscopy was used to investigate the planetary nebula NGC 3242. We analysed the main morphological components of this source, including its knots, but not the halo. In addition to revealing the properties ofthe…

Astrophysics of Galaxies · Physics 2015-06-17 H. Monteiro , D. R. Gonçalves , M. L. Leal-Ferreira , R. L. M. Corradi

We have used the ionisation equilibrium equation to derive the electron density in interstellar clouds in the direction to 13 stars. A linear relation was found, that allows the determination of the electron density from the Mg I and Mg II…

Astrophysics · Physics 2010-04-28 P. Gnacinski , J. K. Sikorski , G. A. Galazutdinov

The discovery of solar neutrinos confirmed that the inner workings of the Sun generally match our theoretical understanding of the fusion process. Solar neutrinos have also played a role in discovering that neutrinos have mass and that they…

High Energy Physics - Phenomenology · Physics 2025-05-19 Peter B. Denton , Charles Gourley

The determination of accurate chemical abundances of planetary nebulae (PN) in different galaxies allows us to obtain important constraints of chemical evolution models for these systems. We have a long term program to derive abundances in…

Cosmology and Nongalactic Astrophysics · Physics 2009-04-17 W. J. Maciel , R. D. D. Costa , T. E. P. Idiart

Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores…

Spectrophotometry constitutes a unique way to obtain the whole diagnostics (density, temperature, ionic abundances) of ionized gas nebulae, thus providing invaluable information about the objects where they reside. If such nebulae are in…

Astrophysics · Physics 2007-05-23 E. Perez-Montero , A. I. Diaz

Many of the fundamental questions in astrophysics can be addressed using spectroscopic observations of photoionized cosmic plasmas. However, the reliability of the inferred astrophysics depends on the accuracy of the underlying atomic data…

Astrophysics · Physics 2007-05-23 Daniel Wolf Savin

Closed analytical formulas are derived for the differential and total cross sections of the non-relativistic photoelectric effect in the three main classes of few-electron atomic systems: (1) neutral atoms and positively charged atomic ions…

Atomic Physics · Physics 2022-09-28 Alexei M. Frolov

The appearance and disappearance of shells and subshells are determined using a previously introduced method of structural analysis. This work extends the approach and applies it to protons, in addition to neutrons, in an attempt to provide…

Nuclear Theory · Physics 2016-04-28 I. Bentley , Y. Colon Rodrıguez , S. Cunningham , A. Aprahamian

Mid-IR observations of planetary nebulae (PNe) have revealed diffuse emission associated to their main nebular shells and outer envelopes or haloes. The interpretation of this emission is uncertain because the broad-band mid-IR images may…

Astrophysics of Galaxies · Physics 2016-11-26 R. A. Marquez-Lugo , G. Ramos-Larios , M. A. Guerrero , R. Vazquez

The role of planetary nebulae as probes for the galactic chemical evolution is reviewed. Their abundances throughout the Galaxy are discussed for key elements, in particular oxygen and other alpha elements. The abundance distribution…

Astrophysics · Physics 2009-11-11 Roberto D. D. Costa , Walter J. Maciel

I review the observational data most relevant for large scale structure. These data determine the system of cosmological parameters: the Hubble parameter, densities of various populations of the Universe, parameters characterizing the power…

Astrophysics · Physics 2007-05-23 Jaan Einasto

We present observations of planetary nebulae with the LOw Frequency ARray (LOFAR) between 120 and 168 MHz. The images show thermal free-free emission from the nebular shells. We have determined the electron temperatures for spatially…

We determine and compare structural, dynamical, and electronic properties of liquid water at near ambient conditions through density-functional molecular dynamics simulations, when using either plane-wave or atomic-orbital basis sets. In…

Chemical Physics · Physics 2016-09-26 Giacomo Miceli , Jürg Hutter , Alfredo Pasquarello

Purpose: In treatment planning of charged-particle radiotherapy, patient heterogeneity is conventionally modeled as variable-density water converted from CT images to best reproduce the stopping power, which may lead to inaccuracies in the…

Medical Physics · Physics 2013-01-08 Nobuyuki Kanematsu , Taku Inaniwa , Yusuke Koba

Absorption-line spectroscopy is a powerful tool used to estimate element abundances in the nearby as well as distant universe. The accuracy of the abundances thus derived is, naturally, limited by the accuracy of the atomic data assumed for…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Romas Kisielius , Varsha P. Kulkarni , Gary J. Ferland , Pavel Bogdanovich , Matt L. Lykins

We use Pantheon Type Ia supernova (SN Ia) apparent magnitude, DES-3yr binned SN Ia apparent magnitude, Hubble parameter, and baryon acoustic oscillation measurements to constrain six spatially flat and non-flat cosmological models. These…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-21 Shulei Cao , Joseph Ryan , Bharat Ratra

Accurate three dimensional reconstructions of atomic positions, and full quantification of the information contained in atom probe tomography data relies on understanding the physical processes taking place during field evaporation of atoms…

Atomic Physics · Physics 2016-01-20 Lan Yao , Travis Withrow , Oscar D. Restrepo , Wolfgang Windl , Emmanuelle A. Marquis