Related papers: Infrared [Fe II] Emission Lines from Radiative Ato…
We used a very large set of models of broad emission line (BEL) clouds in AGN to investigate the formation of the observed Fe II emission lines. We show that photoionized BEL clouds cannot produce both the observed shape and observed…
Emission line studies from Hii regions in galaxies require tools for the inversion of line ratios into desired physical properties. These tools generally come in form of diagnostic ratios/diagrams that are based on grids of photoionisation…
(abridged) Protostellar outflows exhibit large variations in their structure depending on the observed gas emission. This study analyzes the atomic jet and molecular outflow in the Class I protostar, TMC1A to characterize morphology and…
We present near-infrared emission-line flux distributions, excitation and kinematics, as well as stellar kinematics, of the inner 520x520 pc2$ of the Seyfert 2 galaxy NGC5929. The observations were performed with the Gemini's Near-Infrared…
We report four years of radio and X-ray monitoring of the Type IIn supernova SN 2006jd at radio wavelengths with the Very Large Array, Giant Metrewave Radio Telescope and Expanded Very Large Array; at X-ray wavelengths with {\em Chandra},…
Fe II radiative lifetimes were measured applying the time-resolved nonlinear laser-induced fluoresence technique. We investigated 21 levels of up to 47000 1/cm. The uncertainties are typically 2-3%. The lifetimes provide an improved…
Phosphorus (P) is one of the key ingredients for life, yet its origins in galaxies remain poorly understood. In order to investigate the production of P by supernovae, we performed near-infrared (IR) [P II] and [Fe II] line mapping of 26…
It is believed that type II radio bursts are generated by shock waves. In order to understand the generation conditions of type II radio bursts, in this paper, we analyze the physical parameters of a shock front. The type II radio burst we…
We study the low-contrast Fe II emission blends in the ultraviolet (1250--2200A) and optical (4000--6000A) spectra of the Seyfert 1 galaxy NGC 5548 and show that these features vary in flux and that these variations are correlated with…
Here we revisit line identifications of type I supernovae and highlight trace amounts of unburned hydrogen as an important free parameter for the composition of the progenitor. Most 1-dimensional stripped-envelope models of supernovae…
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…
Mg II lines represent one of the strongest emissions from the chromospheric plasma during solar flares. In this article, we studied the Mg II lines observed during the X1 flare on March 29 2014 (SOL2014-03-29T17:48) by IRIS. IRIS detected…
Aims: Ultraviolet (UV) lines of neutral carbon observed in absorption in the local diffuse interstellar medium (ISM) have long revealed that a substantial fraction of the mass of the gas lies at a thermal pressure one to three orders of…
We present spectroscopic observations of FIR fine-structure lines of 26 Seyfert galaxies obtained with the Herschel-PACS spectrometer. These observations are complemented by spectroscopy with Spitzer-IRS and Herschel-SPIRE. The ratios of…
Supernovae of type IIn possess spectral signatures that indicate an intense interaction between the supernova ejecta and surrounding dense circumstellar material cast off by the star in pre-explosion mass-loss episodes. Studying this…
Most Seyfert 1s show strong Fe II lines in their spectrum having the velocity and width of the broad emission lines. To remove the Fe II contribution in these objects, an accurate template is necessary. We used very high signal-to-noise,…
We report a discovery of shocked gas from the supernova remnant (SNR) G357.7+0.3. Our millimeter and submillimeter observations reveal broad molecular lines of CO(2-1), CO(3-2), CO(4-3), 13CO (2-1) and 13CO (3-2), HCO^+ and HCN using HHSMT,…
An object discovered during an infrared survey of the field near the quasar B2 0149+33 has an emission line at 2.25$\mu$m that we interpret as H$\alpha$ at a redshift of 2.43. The K-band image shows two compact components 10 kpc apart…
Using a limited, but representative sample of sources in the ISM of our Galaxy with published spectra from the Infrared Space Observatory, we analyze flux ratios between the major mid-IR emission features (EFs) centered around 6.2, 7.7, 8.6…
We have modeled the gas temperature structure in unstable C-type shocks and obtained predictions for the resultant CO and H2 rotational line emissions, using numerical simulations of the Wardle instability that were carried out by Stone…