Astrophysical computer programs

As part of my research work I develop and maintain a number of Fortran and IDL astrophysical software packages. Contact me if you are interested in using these codes for education or research. Some of these programs are already available for download from dedicated webpages (links below and in the left menu).

Doppler and Zeeman Doppler Imaging codes

Invers10 Magnetic (Zeeman) Doppler Imaging computer program for simultaneous and self-consistent reconstruction of the magnetic and chemical maps of the stellar surface using spectra in several Stokes parameters. This inversion procedure employs synthetic spectra calculated treating in detail polarized radiative transfer in the atmospheres of magnetic spotted stars. The code is written in Fortran and is designed to run on parallel computers using MPI libraries.
Invers12 Multi-element abundance Doppler Imaging code. It is able to reconstruct multiple chemical surface maps using high-resolution intensity observations of stellar spectra. The code is written in Fortran and is designed to run on parallel computers using MPI libraries.
Invers13 Doppler imaging computer program for simultaneous reconstruction of vector magnetic field maps and distribution of temperature inhomogeneities in the late-type active stars. It can also be used to perform chemical mapping of early-type stars self-consistently with atmospheric structure. The code can use both atomic and molecular lines and to work in either circular polarization or full four Stokes parameter mode.
InversV Computer program for mapping distribution of pulsation velocity field over the surfaces of non-radially pulsating stars. The geometry of pulsations is recovered without parameterizing velocity field with the spherical harmonic functions. This allows one to map the structure of non-radial pulsation modes distorted by magnetic field and/or stellar rotation.
InversLSD Code for performing regularized Zeeman Doppler Imaging inversions using least-squares deconvolved (LSD) profiles. The inversion procedure uses a library of precomputed synthetic LSD profiles obtained from full polarized spectrum synthesis calculations or using simplified analytical formulas. Magnetic field topology reconstruction is performed in terms of 2-D surface maps of poloidal and toroidal spherical harmonic components.

Least-squares deconvolution code

iLSD Fortran code to perform least-squares addition of the stellar intensity and polarization spectra yielding a high signal-to-noise ratio average line profile(s). Compared to standard LSD codes, iLSD includes a possibility to use multiple mean profiles (e.g. corresponding to spectral lines of different elements), iteratively adjust line weights, and smooth LSD profiles using regularization.

Spectrum synthesis codes

Synth3 This Fortran code calculates intensity stellar spectra for a given model atmosphere under the assumption of Local Thermodynamical Equilibrium (LTE). Synth3 is optimized for fast spectrum synthesis of large spectral intervals and includes molecular equilibrium solver. The latter enables a self-consistent computation of molecular absorption features as well as atomic spectral lines. A possibility to calculate spectra emergent from stellar atmospheres with a depth-dependent chemical composition and microturbulent velocity is included.
Synmast Further development of the Synthmag code by N. Piskunov. This code has the same capabilities as Synth3 but, in addition, allows one to calculate four Stokes parameter stellar spectra for arbitrary magnetic field strength and orientation. Four Stokes parameter calculations are carried out using numerical solution of the polarized radiative transfer equation in a given stellar atmosphere.

Vertical chemical inversion codes

DDAFit A graphical interface and optimization tool written in IDL for fitting parametrised vertical chemical stratification in the atmospheres of early-type stars. The code models multiple spectral lines using either Synmast or Synth3.
VIP A non-magnetic LTE spectrum synthesis code written in Fortran. This software is aimed at solving general vertical chemical inversion problem by reconstructing an arbitrary smooth vertical distribution of chemical abundances based on the simultaneous fit to many spectral line profiles.

IDL visualization programs

BinMag Widget program to examine theoretical stellar spectra computed with Synth/Synthmag/Synmast/Synth3 and compare them to observations. BinMag applies radial velocity shift and broadening to the theoretical spectra to account for the effects of stellar rotation, radial-tangential macroturbulence, instrumental smearing. The code can also simulate spectra of spectroscopic binary stars and can be used to measure equivalent width, fit line profile shapes, and automatically determine radial velocity and broadening parameters. BinMag interfaces with Synth3, Synmast/Synthmag and SME, allowing user to determine chemical abundances and stellar atmospheric parameters from the observed spectra.
FieldPlot A program to calculate and visualise surface distribution of vector magnetic field for several commonly used low-order multipolar field geometry models.
MapGui GUI package to visualise spherical distributions of scalar and vector fields and produce publication quality plots.
GStokes Widget program to calculate Stokes profile shapes and disk-integrated magnetic observables (mean longitudinal field, field modulus, etc.) using simple analytical line formation models.
DI_demo Widget program to illustrate key principles of Doppler Imaging. A user can construct surface distributions consisting of circular spots, generate simulated observations of line profile variability, and invert these observations using different assumptions and input parameters.