Related papers: Inner-shell 1s - 2p Soft X-ray Absorption Lines
I present a study of the X-ray spectral properties of a sample containing 24 type-1 active galactic nuclei using the medium spectral resolution of ``ASCA''. The sample consists of 20 radio-quiet objects and 4 radio-loud objects. A simple…
In this work, the controversy between the interpretations of recent measurements on dense aluminum plasma created with Linac coherent light sources (LCLS) X-ray free electron laser (FEL) and Orion laser has been addressed. In both kind of…
Moderate and high-resolution measurements (R ~ 40,000) of interstellar resonance lines of D I, C II, N I, O I, Al II, and Si II (light ions) are presented for all available observed targets located within 100 pc which also have…
We present X-ray spectra of four ultraluminous infrared galaxies (ULIRGs) with detectable broad near-infrared emission lines produced by active galactic nuclei (AGNs): Mrk 463, PKS 1345+12, IRAS 05189-2524, and IRAS 07598+6508. With the…
Absorption imaging of ultracold atoms is the foundation for quantitative extraction of information from experiments with ultracold atoms. Due to the limited exposure time available in these systems, the signal-to-noise ratio is largest for…
We use very deep spectra obtained with the Ultraviolet-Visual Echelle Spectrograph in the Very Large Telescope in order to determine the physical conditions, the chemical abundances and the iron depletion factors of four H II regions of the…
High resolution spectra of the hot central star of the planetary nebula (CSPN) M27, acquired with the Far Ultraviolet Spectroscopic Explorer (\FUSE), have revealed an unusually rich set of narrow molecular hydrogen absorption features. This…
Photoionization cross sections and partial ion yields of Xe and XeF$_2$ from Xe 3d$_{5/2}$, Xe 3d$_{3/2}$, and F 1s subshells in the 660--740 eV range are compared to explore effects of the F ligands. The Xe 3d - $\epsilon$f continuum shape…
We present high-resolution soft-X-ray spectra of the prototypical Seyfert 2 galaxy, NGC 1068, taken with XMM-Newton RGS and Chandra LETGS. Its rich emission-line spectrum is dominated by recombination in a warm plasma (bright, narrow…
This paper provides a general reference for deriving the ionizations and metal abundances for absorption-line clouds in photoionization equilibrium with a QSO spectrum. The results include a quantitative assessment of the theoretical…
The nucleus of M87 displays a LINER spectrum at optical wavelengths, with a nuclear disk of nebulosity that is resolved by the Hubble Space Telescope. We present new results from optical and ultraviolet spectra of the central ~40pc as…
Wavelengths of absorption lines in the spectra of galaxies along the line-of-sight to distant quasars can be used to probe the variablility of the fine structure constant, $\alpha$, at high redshifts, provided that the laboratory…
The neutron dose distributions on observation distances and on observation angles were measured using a Wendi-II neutron dose-meter at the deep tumor therapy terminal at HIRFL (Heavy Ion Research Facility in Lanzhou) as 12C ions with…
We report sub-arcsecond resolution X-ray imaging spectroscopy of the low luminosity active galactic nucleus of NGC 4258 and its immediate surroundings with the Chandra X-ray Observatory. NGC 4258 was observed four times, with the first two…
We present near-infrared and millimeter investigations of the nucleus of the infrared luminous galaxy NGC 4418, which previous observations suggest possesses a powerful buried AGN. We found the following main results: (1) The infrared…
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 present X-ray observations of nine Weak-Line Radio Galaxies (WLRGs), optically classified as confirmed or possible Low Ionization Nuclear Emission-line Regions (LINERs). The data were taken from the Chandra, XMM, and BeppoSax archives.…
We present results from a program of optical spectroscopy for 23 nearby galaxy emission-line nuclei. This investigation takes advantage of the spatial resolution of the Hubble Space Telescope to study the structure and energetics of the…
Hydrogen recombination lines (HRLs) are valuable diagnostics of the physical conditions in ionized regions around high-mass stars. Understanding their broadening mechanisms and intensity trends can provide insights into the densities,…
In this paper, we report VLBA radio maps at three frequencies and an ASCA X-ray spectrum of the water megamaser galaxy NGC 2639, which is believed to contain an edge-on viewed accretion disk. The radio observations reveal a compact ($<$ 0.2…