Related papers: Helium-like triplet diagnostics
We present Very Large Telescope/Xshooter spectrophotometric observations of eleven low-redshift (z<0.085) compact star-forming galaxies (`high O32 sample'). These galaxies are characterised by extremely high emission-line ratios…
New theoretical results from large-scale relativistic close coupling calculations reveal the precise effect of resonances in collisional excitation of x-ray lines of Ne-like Fe XVII. Employing the Breit-Pauli R-matrix method and a 89-level…
Line ratio of O IV 1407.3 \AA/1401.1 \AA\- is calculated using mostly our own atomic and collisional data. Energy levels and oscillator strengths needed for this calculation have been calculated using a Hartree-Fock relativistic (HFR)…
We derive new self-consistent theoretical UV, optical, and IR diagnostics for the ISM pressure and electron density in the ionized nebulae of star-forming galaxies. Our UV diagnostics utilize the inter-combination, forbidden and resonance…
Relativistic corrections to the hyperfine splitting are calculated for the triplet $2^3S_1$ state of the helium isotope He$^3$. High precision variational wave functions are employed, where the electron-electron correlations are well…
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…
To get insight in the nature of the ionized gas in the nuclear region of LINERs we have performed a study of HST Halpha imaging of 32 LINERs. The main conclusion from this analysis is that for the large majority of LINERs (84%) an…
The cTTS TW Hya has been observed with high-resolution X-ray spectrometers. Previously found high densities inferred from He-like f/i triplets strongly suggested the detected X-ray emission to be dominated by an accretion shock. Because of…
Chandra High-Energy Transmission Grating (HETG) X-ray spectra are extracted from 17 bright, narrow regions of Cas A and provide unique measurements of their kinematic and plasma states. From the dominant emission lines, e.g. He-like Si, we…
We report a joint experimental and theoretical study using a combination of polarization-controlled free-electron-laser (FEL) and near-infra\-red (NIR) pulses in a synchronized two-color photo\-ionization scheme. Excited He$^+$ ions,…
The Green Bank Telescope H II Region Discovery Survey (GBT HRDS) found hundreds of previously unknown Galactic regions of massive star formation by detecting hydrogen radio recombination line (RRL) emission from candidate H II region…
High-resolution tunable laser spectroscopy is used to measure time-resolved absorption spectra for ten neutral uranium transitions and six singly-ionized transitions in a laser produced plasma. Spectral lineshapes are analyzed to determine…
A sensitive laser spectroscopic method has been applied to the quantitative determination of the isotope ratio of helium at the level of 3He/4He = 10^-7 - 10^-5. The resonant absorption of 1083 nm laser light by the metastable 3He atoms in…
The laser-induced fragmentation dynamics of this most fundamental polar molecule HeH$^+$ are measured using an ion beam of helium hydride and an isotopologue at various wavelengths and intensities. In contrast to the prevailing…
We present a first emission line analysis of a high resolution X-ray spectrum of the stellar wind of theta 1 Ori C obtained with the High Energy Transmission grating Spectrometer onboard the Chandra X-ray Observatory. The spectra are…
The abundance of potassium is derived from X-ray lines observed during flares by the RESIK instrument on the solar mission CORONAS-F between 3.53 A and 3.57 A. The lines include those emitted by He-like K and Li-like K dielectronic…
In order to test the robustness and reliability of the new generation spectral-line identifier PyEMILI, as initially introduced in Paper I, in line identification and establish a reference/benchmark dataset for future spectroscopic studies,…
We present a coherent database of spectroscopic observations of far-IR fine-structure lines from the Herschel/PACS archive for a sample of 170 local AGN, plus a comparison sample of 20 starburst galaxies and 43 dwarf galaxies. Published…
We present the soft X-ray spectrum of the LINER galaxy M81 derived from a long observation with the XMM RGS. The spectrum is dominated by continuum emission from the active nucleus, but also contains emission lines from Fe L, and H-like and…
We present $J$-band ($1.15-1.35 \mu$m) spectroscopy of a sample of nine galaxies showing some degree of LINER activity (classical LINERs, weak-[O {\sc i}] LINERs and transition objects), together with $H$-band spectroscopy for some of them.…