3.1.2. Ascdump: ascii output of plasma properties

3.1.2.1. Overview

One of the drivers in developing SPEX is the desire to be able to get insight into the astrophysics of X-ray sources, beyond merely deriving a set of best-fit parameters like temperature or abundances. The general user might be interested to know ionic concentrations, recombination rates etc. In order to facilitate this SPEX contains options for ascii-output.

Ascii-output of plasma properties can be obtained for any spectral component that uses the basic plasma code of SPEX; for all other components (like power law spectra, gaussian lines, etc.) this sophistication is not needed and therefore not included. There is a choice of properties that can be displayed, and the user can either display these properties on the screen or write it to file.

The possible output types are listed below. Depending on the specific spectral model, not all types are allowed for each spectral component. The keyword in front of each item is the one that should be used for the appropriate syntax.

plas:

basic plasma properties like temperature, electron density etc.

heat:

heating and cooling rates for various processes (for photoionised models only)

abun:

elemental abundances and average charge per element.

icon:

ion concentrations, both with respect to Hydrogen and the relevant elemental abundance.

rion:

ionization rates per atomic subshell, specified according to the different contributing processes.

rate:

total ionization, recombination and charge-transfer rates specified per ion.

time:

recombination time scale per ion according to Bottorf et al. (2000) definition, and relative ion concentrations. Note that the recombination time scale depends upon the hydrogen density, so do not forget to set the relevant density in the model.

grid:

the energy and wavelength grid used in the last evaluation of the spectrum.

con:

list of the ions that contribute to the free-free, free-bound and two-photon continuum emission, followed by the free-free, free-bound, two-photon and total continuum spectrum, for the last plasma layer of the model.

clin:

the continuum, line and total spectrum for each energy bin for the last plasma layer of the model.

line:

the line energy and wavelength, as well as the total line emission (photons/s) for each line contributing to the spectrum, for the last plasma layer of the model. Also given is the natural line width and the Doppler broadening (including thermal and turbulent broadening), expressed as a FWHM in keV. Optionally, the results can be sorted according to various columns as follows (first description, between brackets the acronym): energy (ener), wavelength (wav), ion (ion), line power (powe), natural line width (wid).

ebal:

the energy balance contributions of each layer (only for photoionized plasmas).

nei:

the history of ionisation parameter and temperature in NEI calculations.

snr:

hydrodynamical and other properties of the supernova remnant (only for supernova remnant models such as Sedov, Chevalier etc.).

tcon:

list of the ions that contribute to the free-free, free-bound and two-photon continuum emission, followed by the free-free, free-bound, two-photon and total continuum spectrum, added for all plasma layers of the model.

tcl:

the continuum, line and total spectrum for each energy bin added for all plasma layers of the model.

tlin:

the line energy and wavelength, as well as the total line emission (photons/s) for each line contributing to the spectrum, added for all plasma layers of the model.

pop:

the occupation numbers as well as upwards/downwards loss and gain rates to all quantum levels included.

lev:

the contributions to the population of the energy levels by various processes: positive for gain, negative for loss

elex:

the collisional excitation and de-excitation rates for each level, due to collisions with electrons.

prex:

the collisional excitation and de-excitation rates for each level, due to collisions with protons.

rad:

the radiative transition rates from each level.

two:

the two-photon emission transition rates from each level.

rec:

writes for each atomic level the populating contributions from radiative, dielectronic and charge exchange recombination, as well as inner-shell ionisation

dem:

the emission measure distribution (for the pdem model)

col:

the ionic column densities for the hot, pion, slab, xabs and warm models

tran:

In two subsequent tables, the transmission and equivalent width of absorption lines (first table) and absorption edges (second table) are listed for the hot, pion, slab, xabs and warm models. Optionally, the results (lines only) can be sorted according to various columns as follows (first description, between brackets the acronym): energy (ener), wavelength (wav), ion (ion), optical depth at line center (tau), equivalent width in keV (ewk), equivalent width in Å (ewa), Voigt a parameter (avo).

warm:

the column densities, effective ionization parameters and temperatures of the warm model

3.1.2.2. Syntax

The following syntax rules apply for ascii output:

ascdump terminal #i1 #i2 #a : Dump the output for sky sector #i1 and component #i2 to the terminal screen; the type of output is described by the parameter #a which is listed in the table above.
ascdump file #a1 #i1 #i2 #a2 : As above, but output written to a file with its name given by the parameter #a1. The suffix “.asc” will be appended automatically to this filename.
ascdump terminal #i1 #i2 #a1 sort #a2 : Dump the output for sky sector #i1 and component #i2 to the terminal screen; the type of output is described by the parameter #a1 which is listed in the table above; the results are sorted according to parameter #a2. Sorting is only possible for the “line” and “tran” options; see there for allowed entries.
ascdump file #a1 #i1 #i2 #a2 : As above, but output written to a file with its name given by the parameter #a1. The suffix “.asc” will be appended automatically to this filename.
ascdump set range #r1: unit #a1 : Set the output energy range for the ascii output of: con, clin, lev, line, pop, tcon, tcl, tlin, tran.
ascdump set flux #r1 : Set the minimum line flux/tau to display in the ascii output of: line, tlin and tran.

Warning

Any existing files with the same name will be overwritten.

Warning

Sorting only possible for the line and tran options.

3.1.2.3. Examples

ascdump terminal 3 2 icon : dumps the ion concentrations of component 2 of sky sector 3 to the terminal screen.
ascdump file mydump 3 2 icon : dumps the ion concentrations of component 2 of sky sector 3 to a file named mydump.asc.
ascdump terminal 3 2 line sort pow : dumps the emission line power of component 2 of sky sector 3 to the terminal screen, sorted according to line strength.
ascdump set range 0.1:1.0 unit kev : sets the output energy range to 0.1 to 1.0 keV.
ascdump set flux 1E+35 : sets the minimum line strength for the line and tlin output to 1E+35.