相关论文: Charge Exchange Spectra of Hydrogenic and He-like …

Charge exchange is an important process for the modeling of X-ray spectra obtained by the Chandra, XMM-Newton, and Suzaku X-ray observatories, as well as the anticipated Astro-H mission. The understanding of the observed X-ray spectra…

Recent X-ray observations of star-forming galaxies such as M82 have shown the Ly beta/Ly alpha line ratio of Ne X to be in excess of predictions for thermal electron impact excitation. Here we demonstrate that the observed line ratio may be…

Properties of hot gas outflows from galaxies are generally measured from associated X-ray line emission assuming that it represents atomic transitions in thermally excited hot gas. X-ray line emission, however, can also arise from the…

Lyman x-ray spectra following charge exchange between C$^{6+}$ and H$_2$ are presented for collision velocities between 400 and 2300 km/s (1--30 keV/amu). Spectra were measured by a microcalorimeter x-ray detector capable of fully resolving…

Absolute cross sections are measured for charge-exchange, ionization, and excitation within the same experimental setup for the Li$^{+}-$Ar, K$^{+}-$ Ar, and Na$^{+}-$ He collisions in the ion energy range $0.5-10$ keV. Results of our…

We present a high resolution spectrum of the diffuse X-ray background from 0.1 to 1 keV for a ~1 region of the sky centered at l=90, b=+60 using a 36-pixel array of microcalorimeters flown on a sounding rocket. With an energy resolution of…

The electron capture process was studied for Xe$^{54+}$ colliding with H$_2$ molecules at the internal gas target of the ESR storage ring at GSI, Darmstadt. Cross section values for electron capture into excited projectile states were…

It is shown that the dielectronic satellites (DES) dominate X-ray spectral formation in the 6.7 keV K-alpha complex of Fe XXV at temperatures below that of maximum abundance in collisional ionization equilibrium T_m. Owing to their extreme…

We have measured K-shell x-ray spectra of highly ionized argon and phosphorus following charge exchange with molecular hydrogen at low collision energy in an electron beam ion trap using an x-ray calorimeter array with $\sim$6 eV…

We present the first high-resolution laboratory spectra of X-ray emission following L-shell charge exchange between nickel ions and neutral H2 and He. We employ the commonly used charge exchange models found in XSPEC and SPEX, ACX and…

The reported observations of an unidentified X-ray line feature at $\sim$3.5 keV have driven a lively discussion about its possible dark matter origin. Motivated by this, we have measured the \emph{K}-shell X-ray spectra of highly ionized…

We present an analysis of XRISM and NuSTAR data obtained for the nearby low-Eddington active galactic nucleus NGC 7213. Our goal is to examine whether its He-like and H-like iron emission lines can be reproduced by photoionization or…

We have calculated the equivalent widths of the absorption lines produced by Fe XXV and Fe XXVI in a Compton-thin, low-velocity photoionised material illuminated by the nuclear continuum in AGN. The results, plotted against the ionisation…

We analyze features of the Fe K spectrum of the high-mass X-ray binary Cygnus X-3. The spectrum was obtained with the Chandra High Energy Transmission Grating Spectrometer in the third diffraction order. The increased energy resolution of…

Using the Livermore X-ray Spectral Synthesizer, which calculates spectral models of highly charged ions based on HULLAC atomic data, we investigate the temperature, density, and photoexcitation dependence of the I(11.92 A)/I(11.77 A) line…

Charge exchange between highly charged ions and neutral atoms and molecules has been considered as one of the important mechanisms controlling soft X ray emissions in many astrophysical objects and environments. However, for modeling charge…

Theoretical emission-line ratios involving Fe XI transitions in the 257-407 A wavelength range are derived using fully relativistic calculations of radiative rates and electron impact excitation cross sections. These are subsequently…

The high energy proton-neutron charge exchange scattering reaction is studied in an effective hadron model for the energy range of s from 45.9 to 414.61 GeV*GeV. The main features of the observed differential cross section, the forward peak…

We report the diffuse X-ray emissions from the Sgr A and B regions observed with Suzaku. From the Sgr A region, we found many K-shell transition lines of iron and nickel. The brightest are K alpha lines from FeI, FeXXV and FeXXVI at 6.4…

Aims: Temperature uncertainties plague our understanding of abundance variations within the ISM. Using the PHANGS-MUSE large program, we develop and apply a new technique to model the strong emission lines arising from HII regions in 19…