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Related papers: Revisiting He-like X-ray Emission Line Plasma Diag…

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Most studies of highly ionized plasmas have historically assumed ions are either in photoionization equilibrium, PIE, or collisional ionization equilibrium, CIE, sometimes including multiple phases with different relevant mechanisms.…

Astrophysics of Galaxies · Physics 2022-12-21 Clayton Strawn , Santi Roca-Fàbrega , Joel Primack

We study the ionization and thermal evolution of the intergalactic medium during the epoch of \heii reionization by means of radiation hydrodynamical cosmological simulations. We post-process baryonic density fields from a standard…

Astrophysics · Physics 2007-11-14 Pascal Paschos , Michael L. Norman , James O. Bordner , Robert Harkness

We have developed a modular semi-numerical code that computes the time and spatially dependent ionization of neutral hydrogen (HI), neutral (HeI) and singly ionized helium (HeII) in the intergalactic medium (IGM). The model accounts for…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-02 Anne Hutter

The accepted explanation of the observed dichotomy of two orders of magnitude between in situ measurements of electron density in HII regions, derived from emission line ratios, and average measurements based on integrated emission measure,…

Astrophysics · Physics 2016-08-16 C. Giammanco , J. E. Beckman , A. Zurita , M. Relaño

With the launch of the XRISM microcalorimeter mission, space-based X-ray observations will achieve a record spectral resolving power of $R\equiv E/\Delta E\sim$1200. With this resolving power, emission features associated with…

High Energy Astrophysical Phenomena · Physics 2025-07-31 Chamani M. Gunasekera , Peter A. M. van Hoof , Marios Chatzikos , Gary J. Ferland

Coherent diffraction imaging (CDI) of single molecules at atomic resolution is a major goal for the x-ray free electron lasers (XFELs). However, during an imaging pulse, the fast laser-induced ionization may strongly affect the recorded…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Zoltan Jurek , Robert Thiele , Beata Ziaja , Robin Santra

We present a set of photoionization models that reproduce simultaneously the observed optical and mid-infrared spatial distribution of the HII region NGC595 in the disk of M33 using the code CLOUDY. Both optical (PMAS-Integral Field…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Enrique Perez-Montero , Monica Relano , Jose M. Vilchez , Ana Monreal-Ibero

The hardness of the ionizing continuum from the first sources of UV radiation plays a crucial role in the reionization of the intergalactic medium (IGM). While usual stellar populations have soft spectra, mini-quasars or metal-free stars…

Astrophysics · Physics 2009-10-31 S. Peng Oh , Zoltan Haiman , Martin J. Rees

We analyze the high-resolution X-ray spectrum of the supergiant O-star delta Orionis (O9.5II) with line ratios of He-like ions and a thermal plasma model, and we examine its variability. The O-supergiant delta Ori was observed in the…

Solar and Stellar Astrophysics · Physics 2013-01-30 A. J. J. Raassen , A. M. T. Pollock

We present $[OIII]/H_{\rm \beta}$ emision line flux ratio predictions for galaxies at $z \sim 7-9$ using the MAPPINGS V v5.2.0 photoionization modelling code combined with an analytic galaxy formation model. Properties such as pressure and…

Astrophysics of Galaxies · Physics 2025-04-08 Aadarsh Pathak , J. Stuart B. Wyithe , Ralph S. Sutherland , L. J Kewley

HELicon Experiment for Negative ion source (HELEN-I) with single driver is developed with a focus on the production of negative hydrogen ions. In the Helicon wave heated plasmas, very high plasma densities ($\sim10^{19} m^{-3}$) can be…

Time dependent numerical simulations of the K ALPHA complex of Fe XXV are carried out as a function of temperature/density/radiation field variations in high-temperature astrophysical and laboratory plasmas. In addition to several well…

Astrophysics · Physics 2008-11-26 Justin Oelgoetz , Anil K. Pradhan

K-line profiles emitted from a warm dense plasma environment are used for diagnostics of Ar droplet plasmas created by high energy laser pulses. Analyzing the temporally and spacially integrated spectra, we infer temperature gradients…

Plasma Physics · Physics 2017-09-26 A Sengebusch , H Reinholz , G Röpke

X-ray lasers based on transitions in highly charged \textit{Ni}-like ions generating in the "water window" wavelength range can be pumped by compact laboratory discharge sources. This makes them promising candidates for use as compact…

Plasma Physics · Physics 2021-05-21 N. V. Kalinin , R. M. Feshchenko , I. A. Artyukov , V. A. Burtsev

Charge state distributions of various projectile ions passing through thin carbon foils have been studied in the energy range of 0.7-3.0 MeV/u using x-ray spectroscopy. This technique is found to be appropriate to segregate the charge state…

Plasma Physics · Physics 2015-06-29 Prashant Sharma , Tapan Nandi

Ideal MHD provides an accurate description of low-frequency Alfv\'en waves in fully ionized plasmas. However, higher frequency waves in many plasmas of the solar atmosphere cannot be correctly described by ideal MHD and a more accurate…

Solar and Stellar Astrophysics · Physics 2016-12-07 David Martínez-Gómez , Roberto Soler , Jaume Terradas

This work presents a Bayesian algorithm to fit the recombination and collisionally excited line spectra of gas photoionized by clusters of young stars. The current model consists in fourteen dimensions: two electron temperatures, one…

Astrophysics of Galaxies · Physics 2019-06-05 Vital Fernández , Elena Terlevich , Angeles I. Díaz , Roberto Terlevich

We report the multi-temperature structure of the intracluster medium (ICM) in the Centaurus cluster core observed with XRISM/Resolve. Thanks to its high energy resolution, Resolve enables us to measure fine structures of highly ionized…

We present a new method for inferring the metallicity (Z) and ionization parameter (q) of HII regions and star-forming galaxies using strong nebular emission lines (SEL). We use Bayesian inference to derive the joint and marginalized…

Astrophysics of Galaxies · Physics 2015-06-23 Guillermo A. Blanc , Lisa Kewley , Frédéric P. A. Vogt , Michael A. Dopita