Related papers: A photoionization model grid for novae: estimation…
Photoionization models of HII regions require as input a description of the ionizing SED and of the gas distribution, in terms of ionization parameter U and chemical abundances (e.g. O/H and N/O). A strong degeneracy exists between the…
We present results of study, using observed and published spectra in optical region, of few novae (T CrB, GK Per, RS Oph, V3890 Sgr and V745 Sco) in their quiescence phase and a symbiotic star (BX Mon). Observations were made using the…
A near-infrared spectrum of nova V1716 Scorpii (PNV J17224490-4137160), a recent bright (V_max = 7.3 mag), Fermi-LAT detected gamma-ray source, was modeled using the photoionization code CLOUDY. Abundances were estimated for He, C, N, O,…
We present a code for modelling the ionization conditions of optically thin astrophysical gas structures. Given the gas hydrogen density, equilibrium temperature, elemental abundances, and the ionizing spectrum, the code solves the…
We present modeling and analysis of the ejecta of nova V723 Cas based on spatially resolved IR spectroscopic data from Keck-OSIRIS, with LGSAO (adaptive optics module). The 3D photoionization models include the shell geometry taken from the…
We introduce a new general-purpose time-dependent ionisation network (IN) and a radiation transport (RT) module in the magneto-hydrodynamic (MHD) code PLUTO. Our ionisation network is reliable for temperatures ranging from 5e3 to 3e8 K, and…
The errors inherent to the use of the standard "ionization correction factor" ("i_CF") method of calculating nebular conditions and relative abundances of H, He, N, O, Ne, S, and Ar in emission line nebulae have been investigated under…
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…
Classical novae are significant sources of interstellar material, especially carbon, nitrogen and oxygen. These standard candles are only behind supernovae and $\gamma$-ray bursts as the third brightest objects in the sky, and the most…
A new, fully dynamic and self-consistent radiation hydrodynamics code, suitable for the calculation of supernovae light curves and continuum spectra, is described. It is a multigroup (frequency-dependent) code and includes all important…
Analyses of stellar spectra, stellar populations, and transit light curves rely on grids of synthetic spectra and center-to-limb variations (limb darkening) from model stellar atmospheres. Extensive model grids from PHOENIX, a generalized…
Optical observations of nova V1974 Cygni (Cygni 1992), spanning a 4 year period, have been used to study its spectroscopic evolution. The data cover a wavelength range from $\sim 3200 - 8000$ \AA and follows the nebular evolutionary phase…
We compute a large grid of photoionization models that covers a wide range of physical parameters and is representative of most of the observed PNe. Using this grid, we derive new formulae for the ionization correction factors (ICFs) of He,…
The gas that is present in the interstellar medium is usually very far removed from (local) thermodynamic equilibrium, and in some cases may also not be in a steady-state equilibrium with its surroundings. The physics of this material is…
We present the implementation of dusty, radiation pressure dominated photoionization models applicable to the Narrow Line Regions (NLRs) of Active Galactic Nuclei, using the \mapiii code. We give a grid of the predicted intensities of the…
We perform photoionization modeling of the dusty nova V1280 Scorpii (V1280 Sco) with an aim to study the changes in the physical and chemical parameters. We model pre and post dust phase, optical and near-Infrared (NIR), spectra using the…
We use our new optical-imaging and spectrophotometric survey of key diagnostic emission lines in 30 Doradus, together with CLOUDY photoionization models, to study the physical conditions and ionization mechanisms along over 4000 individual…
Diagnostic diagrams of forbidden lines have been a useful tool for observers in astrophysics for many decades now. They are used to obtain information on the basic physical properties of thin gaseous nebulae. Some diagnostic diagrams are in…
We present bolometric light curves of Type II-plateau supernovae (SNe II-P) obtained using a newly developed, one-dimensional Lagrangian hydrodynamic code with flux-limited radiation diffusion. Using our code we calculate the bolometric…
Here we report new ${\it ab initio}$ calculations of the effective recombination coefficients for the \ion{N}{ii} recombination spectrum. We have taken into account the density dependence of the coefficients arising from the relative…