# ChiantiPy.core package

## Subpackages

- ChiantiPy.core.tests package
  - Submodules
  - ChiantiPy.core.tests.test_Continuum module
  - ChiantiPy.core.tests.test_Ion module
  - ChiantiPy.core.tests.test_Ioneq module
  - ChiantiPy.core.tests.test_Spectrum module
  - Module contents

## Submodules

## ChiantiPy.core.Continuum module

Continuum module

class `ChiantiPy.core.Continuum.``continuum`(ionStr, temperature, abundance=None, em=None, verbose=0)

  Bases: `ChiantiPy.base._IonTrails.ionTrails`

  The top level class for continuum calculations. Includes methods for the calculation of the free-free and free-bound continua.

  Parameters

    - ionStr (str) – CHIANTI notation for the given ion, e.g. ‘fe_12’ that corresponds to the Fe XII ion.

    - temperature (array-like) – In units of Kelvin

  Keyword Arguments

    - abundance (float, str, optional) – Elemental abundance relative to Hydrogen or name of CHIANTI abundance file, without the ‘.abund’ suffix, e.g. ‘sun_photospheric_1998_grevesse’.

    - em (array-like, optional) – Line-of-sight emission measure (\(\int\mathrm{d}l\,n_en_H\)), in units of \(\mathrm{cm}^{-5}\), or the volumetric emission measure (\(\int\mathrm{d}V\,n_en_H\)) in units of \(\mathrm{cm}^{-3}\).

    - verbose (bool) – if True, prints additional info to the console

  Examples

      >>> import ChiantiPy.core as ch
      >>> import numpy as np
      >>> temperature = np.logspace(4,9,20)
      >>> cont = ch.continuum('fe_15',temperature)
      >>> wavelength = np.arange(1,1000,10)
      >>> cont.freeFree(wavelength)
      >>> cont.freeBound(wavelength, include_abundance=True, include_ioneq=False)
      >>> cont.calculate_free_free_loss()
      >>> cont.calculate_free_bound_loss()

  Notes

  The methods for calculating the free-free and free-bound emission and losses return their result to an attribute. See the respective docstrings for more information.

  References

  101(1,2,3)

    Sutherland, R. S., 1998, MNRAS, 300, 321

  102(1,2)

    Verner & Yakovlev, 1995, A&AS, 109, 125

  103(1,2,3,4,5,6)

    Karzas and Latter, 1961, ApJSS, 6, 167

  104(1,2,3,4,5)

    Itoh, N. et al., 2000, ApJS, 128, 125

  106(1,2,3,4,5,6,7,8,9,10)

    Mewe, R. et al., 1986, A&AS, 65, 511

  107(1,2,3,4)

    Rybicki and Lightman, 1979, Radiative Processes in Astrophysics, (Wiley-VCH)

  108(1,2,3,4)

    Gronenschild, E.H.B.M. and Mewe, R., 1978, A&AS, 32, 283

  `calculate_free_bound_loss`(**kwargs)

    Calculate the free-bound energy loss rate of an ion. The result is returned to the free_bound_loss attribute.

    The free-bound loss rate can be calculated by integrating the free-bound emission over the wavelength. This is difficult using the expression in calculate_free_bound_emission so we instead use the approach of 108 and 106. Eq. 1a of 106 can be integrated over wavelength to get the free-bound loss rate,

    \[\frac{dW}{dtdV} = C_{ff}\frac{k}{hc}T^{1/2}G_{fb},\]

    in units of erg \(\mathrm{cm}^3\,\mathrm{s}^{-1}\) where \(G_{fb}\) is the free-bound Gaunt factor as given by Eq. 15 of 106 (see mewe_gaunt_factor for more details) and \(C_{ff}\) is the numerical constant as given in Eq. 4 of 108 and can be written in terms of the fine structure constant \(\alpha\),

    \[C_{ff}\frac{k}{hc} = \frac{8}{3}\left(\frac{\pi}{6}\right)^{1/2}\frac{h^2\alpha^3}{\pi^2}\frac{k_B}{m_e^{3/2}} \approx 1.43\times10^{-27}\]
  `freeBound`(wvl, includeAbund=True, includeIoneq=True, verbose=False)

    Calculates the free-bound (radiative recombination) continuum emissivity of an ion. Provides emissivity in units of ergs \(\mathrm{cm}^{-2}\) \(\mathrm{s}^{-1}\) \(\mathrm{str}^{-1}\) \(\mathrm{\AA}^{-1}\) for an individual ion. If includeAbund is set, the abundance is included. If includeIoneq is set, the ionization equililibrium for the given ion is included

    Notes

    - Uses the Gaunt factors of 103 for recombination to the ground level

    - Uses the photoionization cross sections of 3 to develop the free-bound cross section

    - Does not include the elemental abundance or ionization fraction

    - The specified ion is the target ion

    - uses the corrected version of the K-L bf gaunt factors available in CHIANTI V10

    - revised to calculate the bf cross, fb cross section and the maxwell energy distribution

    - the Verner cross sections are not included for now

    References

    3

      Verner & Yakovlev, 1995, A&AS, 109, 125

  `freeBoundLoss`(includeAbund=True, includeIoneq=True, verbose=False)

    to calculate the free-bound (radiative recombination) energy loss rate coefficient of an ion, the ion is taken to be the target ion, including the elemental abundance and the ionization equilibrium population uses the Gaunt factors of 103 Karzas, W.J, Latter, R, 1961, ApJS, 6, 167 provides rate = erg cm^-2 s^-1 .. rubric:: Notes

    - Uses the Gaunt factors of 103 for recombination to the ground level

    - Uses the photoionization cross sections of 2 to develop the free-bound cross section

    - Does not include the elemental abundance or ionization fraction

    - The specified ion is the target ion

    - uses the corrected version of the K-L bf gaunt factors available in CHIANTI V10

    - revised to calculate the bf cross, fb cross section and the maxwell energy distribution

    - the Verner cross sections are not included for now

    - using the RESTART formulation

    References

    2

      Verner & Yakovlev, 1995, A&AS, 109, 125

  `freeBoundLossMao`(includeAbund=False, includeIoneq=False)

    to calculate the radiative loss rate from the parameters of Mao J., Kaastra J., Badnell N.R. <Astron. Astrophys. 599, A10 (2017)>=2017A&A…599A..10M

  `freeBoundLossMewe`(**kwargs)

    Calculate the free-bound energy loss rate of an ion. The result is returned to the free_bound_loss attribute.

    The free-bound loss rate can be calculated by integrating the free-bound emission over the wavelength. This is difficult using the expression in calculate_free_bound_emission so we instead use the approach of 108 and 106. Eq. 1a of 106 can be integrated over wavelength to get the free-bound loss rate,

    \[\frac{dW}{dtdV} = C_{ff}\frac{k}{hc}T^{1/2}G_{fb},\]

    in units of erg \(\mathrm{cm}^3\,\mathrm{s}^{-1}\) where \(G_{fb}\) is the free-bound Gaunt factor as given by Eq. 15 of 106 (see mewe_gaunt_factor for more details) and \(C_{ff}\) is the numerical constant as given in Eq. 4 of 108 and can be written in terms of the fine structure constant \(\alpha\),

    \[C_{ff}\frac{k}{hc} = \frac{8}{3}\left(\frac{\pi}{6}\right)^{1/2}\frac{h^2\alpha^3}{\pi^2}\frac{k_B}{m_e^{3/2}} \approx 1.43\times10^{-27}\]
  `freeFree`(wavelength, includeAbund=True, includeIoneq=True, **kwargs)

    Calculates the free-free emission for a single ion. The result is returned as a dict to the FreeFree attribute. The dict has the keywords intensity, wvl, temperature, em.

    The free-free emission for the given ion is calculated according Eq. 5.14a of 107, substituting \(\nu=c/\lambda\), dividing by the solid angle, and writing the numerical constant in terms of the fine structure constant \(\alpha\),

    \[\frac{dW}{dtdVd\lambda} = \frac{c}{3m_e}\left(\frac{\alpha h}{\pi}\right)^3\left(\frac{2\pi}{3m_ek_B}\right)^{1/2}\frac{Z^2}{\lambda^2T^{1/2}}\exp{\left(-\frac{hc}{\lambda k_BT}\right)}\bar{g}_{ff},\]

    where \(Z\) is the nuclear charge, \(T\) is the electron temperature in K, and \(\bar{g}_{ff}\) is the velocity-averaged Gaunt factor. The Gaunt factor is estimated using the methods of 104 and 101, depending on the temperature and energy regime. See itoh_gaunt_factor and sutherland_gaunt_factor for more details.

    The free-free emission is in units of erg \(\mathrm{cm}^3\mathrm{s}^{-1}\mathrm{\mathring{A}}^{-1}\mathrm{str}^{-1}\). If the emission measure has been set, the units will be multiplied by \(\mathrm{cm}^{-5}\) or \(\mathrm{cm}^{-3}\), depending on whether it is the line-of-sight or volumetric emission measure, respectively.

    Parameters

      - wavelength (array-like) – In units of angstroms

      - includeAbund (bool, optional) – If True, include the ion abundance in the final output.

      - includeIoneq (bool, optional) – If True, include the ionization equilibrium in the final output

  `freeFreeLoss`(includeAbund=True, includeIoneq=True, **kwargs)

    Calculate the free-free energy loss rate of an ion. The result is returned to the FreeFreeLoss attribute.

    The free-free radiative loss rate is given by Eq. 5.15a of 107. Writing the numerical constant in terms of the fine structure constant \(\alpha\),

    \[\frac{dW}{dtdV} = \frac{4\alpha^3h^2}{3\pi^2m_e}\left(\frac{2\pi k_B}{3m_e}\right)^{1/2}Z^2T^{1/2}\bar{g}_B\]

    where where \(Z\) is the nuclear charge, \(T\) is the electron temperature, and \(\bar{g}_{B}\) is the wavelength-averaged and velocity-averaged Gaunt factor. The Gaunt factor is calculated using the methods of 103. Note that this expression for the loss rate is just the integral over wavelength of Eq. 5.14a of 103, the free-free emission, and is expressed in units of erg \(\mathrm{cm}^3\,\mathrm{s}^{-1}\).

  `free_free_loss`(includeAbund=True, includeIoneq=True, **kwargs)

    Calculate the free-free energy loss rate of an ion. The result is returned to the free_free_loss attribute.

    The free-free radiative loss rate is given by Eq. 5.15a of 107. Writing the numerical constant in terms of the fine structure constant \(\alpha\),

    \[\frac{dW}{dtdV} = \frac{4\alpha^3h^2}{3\pi^2m_e}\left(\frac{2\pi k_B}{3m_e}\right)^{1/2}Z^2T^{1/2}\bar{g}_B\]

    where where \(Z\) is the nuclear charge, \(T\) is the electron temperature, and \(\bar{g}_{B}\) is the wavelength-averaged and velocity-averaged Gaunt factor. The Gaunt factor is calculated using the methods of 103. Note that this expression for the loss rate is just the integral over wavelength of Eq. 5.14a of 107, the free-free emission, and is expressed in units of erg \(\mathrm{cm}^3\,\mathrm{s}^{-1}\).

  `ioneqOne`()

    Provide the ionization equilibrium for the selected ion as a function of temperature. Similar to but not identical to ion.ioneqOne() - the ion class needs to be able to handle the ‘dielectronic’ ions returned in self.IoneqOne

  `ioneq_one`(stage, **kwargs)

    Calculate the equilibrium fractional ionization of the ion as a function of temperature.

    Uses the ChiantiPy.core.ioneq module and does a first-order spline interpolation to the data. An ionization equilibrium file can be passed as a keyword argument, ioneqfile. This can be passed through as a keyword argument to any of the functions that uses the ionization equilibrium.

    Parameters

      stage (int) – Ionization stage, e.g. 25 for Fe XXV

  `itoh_gaunt_factor`(wavelength)

    Calculates the free-free gaunt factors of 104.

    An analytic fitting formulae for the relativistic Gaunt factor is given by Eq. 4 of 104,

    \[g_{Z} = \sum^{10}_{i,j=0}a_{ij}t^iU^j\]

    where,

    \[t = \frac{1}{1.25}(\log_{10}{T} - 7.25),\ U = \frac{1}{2.5}(\log_{10}{u} + 1.5),\]

    \(u=hc/\lambda k_BT\), and \(a_{ij}\) are the fitting coefficients and are read in using ChiantiPy.tools.io.itohRead and are given in Table 4 of 104. These values are valid for \(6<\log_{10}(T)< 8.5\) and \(-4<\log_{10}(u)<1\).

    See also

    `ChiantiPy.tools.io.itohRead()`

      Read in Gaunt factor coefficients from 104

  `mewe_gaunt_factor`(**kwargs)

    Calculate the Gaunt factor according to 106 for a single ion \(Z_z\).

    Using Eq. 9 of 106, the free-bound Gaunt factor for a single ion can be written as,

    \[G_{fb}^{Z,z} = \frac{E_H}{k_BT}\mathrm{Ab}(Z)\frac{N(Z,z)}{N(Z)}f(Z,z,n)\]

    where \(E_H\) is the ground-state potential of H, \(\mathrm{Ab}(Z)\) is the elemental abundance, \(\frac{N(Z,z)}{N(Z)}\) is the fractional ionization, and \(f(Z,z,n)\) is given by Eq. 10 and is approximated by Eq 16 as,

    \[f(Z,z,n) \approx f_2(Z,z,n_0) = 0.9\frac{\zeta_0z_0^4}{n_0^5}\exp{\left(\frac{E_Hz_0^2}{n_0^2k_BT}\right)} + 0.42\frac{z^4}{n_0^{3/2}}\exp{\left(\frac{E_Hz^2}{(n_0 + 1)^2k_BT}\right)}\]

    where \(n_0\) is the principal quantum number, \(z_0\) is the effective charge (see Eq. 7 of 106), and \(\zeta_0\) is the number of vacancies in the 0th shell and is given in Table 1 of 106. Here it is calculated in the same manner as in fb_rad_loss.pro of the CHIANTI IDL library. Note that in the expression for \(G_{fb}\), we have not included the \(N_H/n_e\) factor.

    Raises

      ValueError – If no .fblvl file is available for this ion

  `rrRate`()

    Provide the radiative recombination rate coefficient as a function of temperature (K). a revised copy of the Ion method

  `sutherland_gaunt_factor`(wavelength)

    Calculates the free-free gaunt factor calculations of 101.

    The Gaunt factors of 101 are read in using ChiantiPy.tools.io.gffRead as a function of \(u\) and \(\gamma^2\). The data are interpolated to the appropriate wavelength and temperature values using ~scipy.ndimage.map_coordinates.

  `vernerCross`(wvl)

    Calculates the photoionization cross-section using data from 102 for transitions to the ground state.

    The photoionization cross-section can be expressed as \(\sigma_i^{fb}=F(E/E_0)\) where \(F\) is an analytic fitting formula given by Eq. 1 of 102,

    \[F(y) = ((y-1)^2 + y_w^2)y^{-Q}(1 + \sqrt{y/y_a})^{-P},\]

    where \(E\) is the photon energy, \(n\) is the principal quantum number, \(l\) is the orbital quantum number, \(Q = 5.5 + l - 0.5P\), and \(\sigma_0,E_0,y_w,y_a,P\) are fitting paramters. These can be read in using ChiantiPy.tools.io.vernerRead.

## ChiantiPy.core.Ion module

Ion class

class `ChiantiPy.core.Ion.``ion`(ionStr, temperature=None, eDensity=None, pDensity='default', radTemperature=None, rStar=None, abundance=None, setup=True, em=None, verbose=0)

  Bases: `ChiantiPy.base._IoneqOne.ioneqOne`, `ChiantiPy.base._IonTrails.ionTrails`, `ChiantiPy.base._SpecTrails.specTrails`

  The top level class for performing spectral calculations for an ion in the CHIANTI database.

  Parameters

    - ionStr (str) – CHIANTI notation for the given ion, e.g. ‘fe_12’ that corresponds to the Fe XII ion.

    - temperature (float , tuple, list, ~numpy.ndarray, optional) – Temperature array (Kelvin)

    - eDensity (float , tuple, list, or ~numpy.ndarray, optional) – Electron density array (\(\mathrm{cm^{-3}}\) )

    - pDensity (float, tuple, list or ~numpy.ndarray, optional) – Proton density (\(\mathrm{cm}^{-3}\) )

    - radTemperature (float or ~numpy.ndarray, optional) – Radiation black-body temperature (in Kelvin)

    - rStar (float or ~numpy.ndarray, optional) – Distance from the center of the star (in stellar radii)

    - abundance (float or str, optional) – Elemental abundance relative to Hydrogen or name of CHIANTI abundance file to use, without the ‘.abund’ suffix, e.g. ‘sun_photospheric_1998_grevesse’.

    - setup (bool or str, optional) – If True, run ion setup function. Otherwise, provide a limited number of attributes of the selected ion

    - em (float or ~numpy.ndarray, optional) – Emission Measure, for the line-of-sight emission measure (\(\mathrm{\int \, n_e \, n_H \, dl}\)) (\(\mathrm{cm}^{-5}\).), for the volumetric emission measure \(\mathrm{\int \, n_e \, n_H \, dV}\) (\(\mathrm{cm^{-3}}\)).

  Variables

    - IonStr (str) – Name of element plus ion, e.g. fe_12 for Fe XII

    - Z (int) – the nuclear charge, 26 for fe_12.

    - Ion (int) – the ionization stage, 12 for fe_12.

    - Dielectronic (bool) – true if the ion is a ‘dielectronic’ ion where the levels are populated by dielectronic recombination.

    - Spectroscopic (str) – the spectroscopic notation for the ion, such as Fe XII for fe_12.

    - Filename (str) – the complete name of the file generic filename in the CHIANTI database, such as $XUVTOP/fe/fe_12/fe_12.

    - Ip (float) – the ionization potential of the ion

    - FIP (float) – the first ionization potential of the element

    - Defaults (dict) – these are specified by the software unless a chiantirc file is found in ‘$HOME/.chianti’:

  Notes

  The keyword arguments temperature, eDensity, radTemperature, rStar, em must all be either a float or have the same dimension as the rest if specified as lists, tuples or arrays.

  The Defaults dict should have the following keys:

  - abundfile, the elemental abundance file, unless specified in chiantirc this defaults to sun_photospheric_1998_grevesse.

  - ioneqfile, the ionization equilibrium file name. Unless specified in ‘chiantirc’ this is defaults to chianti. Other choices are availble in $XUVTOP/ioneq

  - wavelength, the units of wavelength (Angstroms, nm, or kev), unless specified in the ‘chiantirc’ this is defaults to ‘angstrom’.

  - flux, specified whether the line intensities are give in energy or photon fluxes, unless specified in the ‘chiantirc’ this is defaults to energy.

  - gui, specifies whether to use gui selection widgets (True) or to make selections on the command line (False). Unless specified in the ‘chiantirc’ this is defaults to False.

  `boundBoundLoss`(allLines=1)

    Calculate the summed radiative loss rate for all spectral lines of the specified ion.

    Parameters

      - allLines (bool) – If True, include losses from both observed and unobserved lines. If False, only include losses from observed lines.

      - includes elemental abundance and ionization fraction.

    Returns

      - creates the attribute

      - BoundBoundLoss (dict with the keys below.) – rate : the radiative loss rate (\(\mathrm{erg \, cm^{-3}} \, \mathrm{s}^{-1}\)) per unit emission measure.

        temperature : (K).

        eDensity : electron density (\(\mathrm{cm^{-3}}\))

  `diCross`(energy=None, verbose=False)

    Calculate the direct ionization cross section (cm$^2) as a function of the incident electron energy in eV, puts values into attribute DiCross

    Parameters

      - energy (array-like) – incident electron energy in eV

      - verbose (bool, int) – with verbose set to True, printing is enabled

    Variables

      DiCross (dict) – keys: energy, cross

  `diRate`(ngl=20)

    Calculate the direct ionization rate coefficient as a function of temperature (K)

  `drPopulate`(popCorrect=1, verbose=0)

    Calculate level populations for specified ion. possible keyword arguments include temperature, eDensity, pDensity, radTemperature and rStar different from method populate() in that it includes the dielectronic recombination from all levels specified by the .auto file - consequently, it also calculates the populations of the higher ionization stage

  `drRate`()

    Provide the dielectronic recombination rate coefficient as a function of temperature (K).

  `drRateLvl`(verbose=0)

    to calculate the level resolved dielectronic rate from the higher ionization stage to the ion of interest rates are determined from autoionizing A-values the dictionary self.DrRateLvl contains rate = the dielectronic rate into an autoionizing level effRate = the dielectronic rate into an autoionizing level mutilplied by the branching ratio for a stabilizing transition totalRate = the sum of all the effRates

  `eaCross`(energy=None, verbose=False)

    Provide the excitation-autoionization cross section.

    Energy is given in eV.

  `eaDescale`()

    Calculates the effective collision strengths (upsilon) for excitation-autoionization as a function of temperature.

  `eaRate`()

    Calculate the excitation-autoionization rate coefficient.

  `emiss`(allLines=True)

    Calculate the emissivities for lines of the specified ion.

    units: ergs s^-1 str^-1

    Does not include elemental abundance or ionization fraction

    Wavelengths are sorted

    set allLines = True to include unidentified lines

  `emissList`(index=-1, wvlRange=None, wvlRanges=None, top=10, relative=0, outFile=0)

    List the emissivities.

    wvlRange, a 2 element tuple, list or array determines the wavelength range

    Top specifies to plot only the top strongest lines, default = 10

    normalize = 1 specifies whether to normalize to strongest line, default = 0

  `emissPlot`(index=-1, wvlRange=None, top=10, linLog='lin', relative=0, verbose=0, plotFile=0, saveFile=0)

    Plot the emissivities.

    wvlRange, a 2 element tuple, list or array determines the wavelength range

    Top specifies to plot only the top strongest lines, default = 10

    linLog specifies a linear or log plot, want either lin or log, default = lin

    normalize = 1 specifies whether to normalize to strongest line, default = 0

  `emissRatio`(wvlRange=None, wvlRanges=None, top=10)

    Plot the ratio of 2 lines or sums of lines. Shown as a function of density and/or temperature. For a single wavelength range, set wvlRange = [wMin, wMax] For multiple wavelength ranges, set wvlRanges = [[wMin1,wMax1],[wMin2,wMax2], …] A plot of relative emissivities is shown and then a dialog appears for the user to choose a set of lines.

  `gofnt`(wvlRange=None, top=10, verbose=False, plot=True)

    Calculate the ‘so-called’ G(T) function.

    Given as a function of both temperature and eDensity.

    Only the top( set by ‘top’) brightest lines are plotted. the G(T) function is returned in a dictionary self.Gofnt

    Note: if the default value for gui is set to False, then it is usually

      necessary to invoke this method twice to get the desired result.

    Keyword Arguments

      - wvlRange (array-like) – the wavelength range to be considered, a two element array-type

      - top (int) – specifies to plot only the top strongest lines, default = 10

      - verbose (bool) – if True, additional information is printed to the console

      - plot (bool) – if True, the G(T) functionis plotted, default - True

  `intensity`(allLines=1, verbose=0)

    Calculate the intensities for lines of the specified ion.

    units: ergs cm^-3 s^-1 str^-1

    includes elemental abundance and ionization fraction.

    the emission measure ‘em’ is included if specified

  `intensityRatioInterpolate`(data, scale='lin', plot=0, verbose=0)

    to take a set of date and interpolate against the IntensityRatio the scale can be one of ‘lin’/’linear’ [default], ‘loglog’, ‘logx’, ‘logy’,

  `ionizCross`(energy=None)

    Provides the total ionization cross section.

    Notes

    uses diCross and eaCross.

  `ionizRate`(ngl=20)

    Provides the total ionization rate.

    Calls diRate and eaRate.

  `p2eRatio`()

    Calculates the proton density to electron density ratio using Eq. 7 of 1.

    Notes

    Uses the abundance and ionization equilibrium.

    References

    1

      Young, P. R. et al., 2003, ApJS, 144, 135

  `popPlot`(top=10, levels=[], scale=0, plotFile=0, outFile=0, pub=0, addTitle=None, addLegend=True)

    Plots populations vs temperature or eDensity.

    top specifies the number of the most highly populated levels to plot (the default)

    or can set levels to an array such as a list to set the desired levels to plot

    if scale is set, then the population, if plotted vs. density, is divided by density - only useful if plotting level populations vs density

    if pub is set, the want publication plots (bw, lw=2).

    if addLegend is set, a matplotlib legend is added

  `populate`(popCorrect=1, verbose=0)

    Calculate level populations for specified ion. possible keyword arguments include temperature, eDensity, pDensity, radTemperature and rStar populate assumes that all of the population in the higher ionization stages exists only in the ground level use drPopulate() for cases where the population of various levels in the higher ionization stage figure into the calculation

  `recombRate`()

    Provides the total recombination rate coefficient.

    Calls drRate and rrRate

  `rrRate`()

    Provide the radiative recombination rate coefficient as a function of temperature (K).

  `rrlvlDescale`(verbose=1)

    Interpolate and extrapolate rrlvl rates. Used in level population calculations.

  `setup`(alternate_dir=None, verbose=False)

    Setup various CHIANTI files for the ion including .wgfa, .elvlc, .scups, .psplups, .reclvl, .cilvl, and others.

    Parameters

      - alternate_dir (str) – directory cotaining the necessary files for a ChiantiPy ion; use to setup an ion with files not in the current CHIANTI directory

      - verbose (bool)

    Notes

    If ion is initiated with setup=False, call this method to do the setup at a later point.

  `setupIonrec`(alternate_dir=None, verbose=False)

    Setup method for ion recombination and ionization rates.

    Notes

    Allows a bare-bones ion object to be setup up with just the ionization and recombination rates. For ions without a complete set of files - one that is not in the MasterList.

  `spectrum`(wavelength, filter=(<function gaussianR>, 1000.0), label=0, allLines=1)

    Calculates the line emission spectrum for the specified ion.

    Convolves the results of intensity to make them look like an observed spectrum the default filter is the gaussianR filter with a resolving power of 1000. Other choices include chianti.filters.box and chianti.filters.gaussian. When using the box filter, the width should equal the wavelength interval to keep the units of the continuum and line spectrum the same.

    includes ionization equilibrium and elemental abundances

    can be called multiple times to use different filters and widths uses label to keep the separate applications of spectrum sorted by the label for example, do .spectrum( …. label = ‘test1’) and do .spectrum( …. label = ‘test2’) then will get self.Spectrum.keys() = test1, test2 and self.Spectrum[‘test1’] = {‘intensity’:aspectrum, ‘wvl’:wavelength, ‘filter’:useFilter.__name__, ‘filterWidth’:useFactor}

    Notes

    scipy.ndimage.filters also includes a range of filters.

  `twoPhoton`(wvl, verbose=False)

    to calculate the two-photon continuum - only for hydrogen- and helium-like ions includes the elemental abundance and the ionization equilibrium includes the emission measure if specified discussed in 105

    References

    105

      Young et al., 2003, ApJSS, 144, 135

  `twoPhotonEmiss`(wvl)

    To calculate the two-photon continuum rate coefficient - only for hydrogen- and helium-like ions

  `twoPhotonLoss`()

    to calculate the two-photon energy loss rate - only for hydrogen- and helium-like ions includes the elemental abundance and the ionization equilibrium does not include the emission measure

  `upsilonDescale`(prot=0)

    Provides the temperatures and effective collision strengths (upsilons) set prot for proton rates otherwise, ce will be set for electron collision rates uses the new format “scups” files

## ChiantiPy.core.Ioneq module

Ionization equilibrium class

class `ChiantiPy.core.Ioneq.``ioneq`(el_or_z)

  Bases: `object`

  Calculation ion fractions as a function of temperature assuming ionization equilibrium.

  Parameters

    el_or_z (int or str) – Atomic number or symbol

  Note

  When either loading or calculating a set of ion fractions, the temperature and ion fractions are returned to the Temperature and Ioneq attributes, respectively.

  `calculate`(temperature)

    Calculate ion fractions for given temperature array using the total ionization and recombination rates.

  `load`(ioneqName=None)

    Read temperature and ion fractions from a CHIANTI “.ioneq” file.

  `plot`(stages=0, tRange=0, yr=0, oplot=False, label=1, title=1, bw=False, semilogx=0, verbose=0)

    Plots the ionization equilibria.

    self.plot(tRange=None, yr=None, oplot=False) stages = sequence of ions to be plotted, neutral == 1, fully stripped == Z+1 tRange = temperature range, yr = ion fraction range

    for overplotting: oplot=”ioneqfilename” such as ‘mazzotta’ or if oplot=True or oplot=1 and a widget will come up so that a file can be selected. bw, if True, the plot is made in black and white

  `plotRatio`(stageN, stageD, tRange=0, yr=0, label=1, title=1, bw=0, semilogx=1, verbose=0)

    Plots the ratio of the ionization equilibria of two stages of a given element

    self.plotRatio(stageN, stageD) stages = sequence of ions to be plotted, neutral == 1, fully stripped == Z+1 stageN = numerator stageD = denominator tRange = temperature range, yr = ion fraction range

## ChiantiPy.core.IpyMspectrum module

`ChiantiPy.core.IpyMspectrum.``doAll`(inpt)

  to process ff, fb and line inputs

class `ChiantiPy.core.IpyMspectrum.``ipymspectrum`(temperature, eDensity, wavelength, filter=(<function gaussianR>, 1000.0), label=None, elementList=None, ionList=None, minAbund=None, keepIons=0, doLines=1, doContinuum=1, allLines=1, em=None, abundance=None, verbose=0, timeout=0.1)

  Bases: `ChiantiPy.base._IonTrails.ionTrails`, `ChiantiPy.base._SpecTrails.specTrails`

  this is the multiprocessing version of spectrum for using inside an IPython Qtconsole or notebook.

  be for creating an instance, it is necessary to type something like the following into a console

  > ipcluster start –n=3

  this is the way to invoke things under the IPython 6 notation

  Calculate the emission spectrum as a function of temperature and density.

  temperature and density can be arrays but, unless the size of either is one (1), the two must have the same size

  the returned spectrum will be convolved with a filter of the specified width on the specified wavelength array

  the default filter is gaussianR with a resolving power of 100. Other filters, such as gaussian, box and lorentz, are available in ChiantiPy.filters. When using the box filter, the width should equal the wavelength interval to keep the units of the continuum and line spectrum the same.

  A selection of elements can be make with elementList a list containing the names of elements that are desired to be included, e.g., [‘fe’,’ni’]

  A selection of ions can be make with ionList containing the names of the desired lines in Chianti notation, i.e. C VI = c_6

  Both elementList and ionList can not be specified at the same time

  a minimum abundance can be specified so that the calculation can be speeded up by excluding elements with a low abundance. With solar photospheric abundances -

  setting minAbund = 1.e-4 will include H, He, C, O, Ne setting minAbund = 2.e-5 adds N, Mg, Si, S, Fe setting minAbund = 1.e-6 adds Na, Al, Ar, Ca, Ni

  Setting em will multiply the spectrum at each temperature by the value of em.

  em [for emission measure], can be a float or an array of the same length as the temperature/density. allLines = 1 will include lines with either theoretical or observed wavelengths. allLines=0 will include only those lines with observed wavelengths

  timeout - a small but non-zero value seems to be necessary

## ChiantiPy.core.Mspectrum module

class `ChiantiPy.core.Mspectrum.``mspectrum`(temperature, eDensity, wavelength, filter=(<function gaussianR>, 1000.0), label=0, elementList=None, ionList=None, minAbund=None, keepIons=0, abundance=None, doLines=1, doContinuum=1, allLines=1, em=None, proc=3, verbose=0, timeout=0.1)

  Bases: `ChiantiPy.base._IonTrails.ionTrails`, `ChiantiPy.base._SpecTrails.specTrails`

  this is the multiprocessing version of spectrum set proc to the desired number of processors, default=3

  Calculate the emission spectrum as a function of temperature and density.

  temperature and density can be arrays but, unless the size of either is one (1), the two must have the same size

  the returned spectrum will be convolved with a filter of the specified width on the specified wavelength array

  the default filter is gaussianR with a resolving power of 100. Other filters, such as gaussian, box and lorentz, are available in chianti.filters. When using the box filter, the width should equal the wavelength interval to keep the units of the continuum and line spectrum the same.

  A selection of elements can be make with elementList a list containing the names of elements that are desired to be included, e.g., [‘fe’,’ni’]

  A selection of ions can be make with ionList containing the names of the desired lines in Chianti notation, i.e. C VI = c_6

  Both elementList and ionList can not be specified at the same time

  a minimum abundance can be specified so that the calculation can be speeded up by excluding elements with a low abundance. With solar photospheric abundances -

  setting minAbund = 1.e-4 will include H, He, C, O, Ne setting minAbund = 2.e-5 adds N, Mg, Si, S, Fe setting minAbund = 1.e-6 adds Na, Al, Ar, Ca, Ni

  Setting em will multiply the spectrum at each temperature by the value of em.

  em [for emission measure], can be a float or an array of the same length as the temperature/density. allLines = 1 will include lines with either theoretical or observed wavelengths. allLines=0 will include only those lines with observed wavelengths

  proc = the number of processors to use timeout - a small but non-zero value seems to be necessary

## ChiantiPy.core.RadLoss module

class `ChiantiPy.core.RadLoss.``radLoss`(temperature, eDensity, elementList=None, ionList=None, minAbund=None, doContinuum=1, abundance=None, verbose=0, allLines=1, keepIons=0)

  Bases: `ChiantiPy.base._IonTrails.ionTrails`, `ChiantiPy.base._SpecTrails.specTrails`

  Calculate the emission spectrum as a function of temperature and density.

  includes elemental abundances or ionization equilibria

  temperature and density can be arrays but, unless the size of either is one (1), the two must have the same size

  the returned spectrum will be convolved with a filter of the specified width on the specified wavelength array

  the default filter is gaussianR with a resolving power of 1000. Other filters, such as gaussian, box and lorentz, are available in ChiantiPy.filters. When using the box filter, the width should equal the wavelength interval to keep the units of the continuum and line spectrum the same.

  A selection of ions can be make with ionList containing the names of the desired lines in Chianti notation, i.e. C VI = c_6

  a minimum abundance can be specified so that the calculation can be speeded up by excluding elements with a low abundance. With solar photospheric abundances -

  setting minAbund = 1.e-4 will include H, He, C, O, Ne setting minAbund = 2.e-5 adds N, Mg, Si, S, Fe setting minAbund = 1.e-6 adds Na, Al, Ar, Ca, Ni

  Setting em will multiply the spectrum at each temperature by the value of em.

  em [for emission measure], can be a float or an array of the same length as the temperature/density.

  abundance: to select a particular set of abundances, set abundance to the name of a CHIANTI abundance file,

    without the ‘.abund’ suffix, e.g. ‘sun_photospheric_1998_grevesse’ If set to a blank (‘’), a gui selection menu will popup and allow the selection of an set of abundances

  `radLossPlot`(title=0)

    to plot the radiative losses vs temperature

## ChiantiPy.core.Bunch module

class `ChiantiPy.core.Bunch.``bunch`(temperature, eDensity, wvlRange, elementList=None, ionList=None, minAbund=None, keepIons=False, em=None, abundance=None, verbose=False, allLines=True)

  Bases: `ChiantiPy.base._IonTrails.ionTrails`, `ChiantiPy.base._SpecTrails.specTrails`

  Calculate the emission line spectrum as a function of temperature and density.

  ‘bunch’ is very similar to ‘spectrum’ except that continuum is not calculated and the spectrum is not convolved over a filter. However, this can be done with the inherited convolve method

  one of the convenient things is that all of the instantiated ion classes, determined through such keywords as ‘elementList’, ‘ionList’, and ‘minAbund’ are kept in a dictionary self.IonInstances where self.IonInstances[‘mg_7’] is the class instance of ChiantiPy.core.ion for ‘mg_7’. All its methods and attributes are available.

  includes elemental abundances and ionization equilibria

  the set of abundances, a file in $XUVTOP/abundance, can be set with the keyword argument ‘abundanceName’

  temperature and density can be arrays but, unless the size of either is one (1), the two must have the same size

  Inherited methods include ‘intensityList’, ‘intensityRatio’ (between lines of different ions), and ‘intensityRatioSave’ and ‘convolve’.

  A selection of elements can be make with elementList a list containing the names of elements that are desired to be included, e.g., [‘fe’,’ni’]

  A selection of ions can be make with ionList containing the names of the desired lines in Chianti notation, i.e. C VI = c_6

  Both elementList and ionList can not be specified at the same time

  a minimum abundance can be specified so that the calculation can be speeded up by excluding elements with a low abundance. With solar photospheric abundances -

  setting minAbund = 1.e-4 will include H, He, C, O, Ne setting minAbund = 2.e-5 adds N, Mg, Si, S, Fe setting minAbund = 1.e-6 adds Na, Al, Ar, Ca, Ni

  At least one of elementList, ionList, or minAbund must be set in order for ‘bunch’ to include any ions.

  Setting em will multiply the spectrum at each temperature by the value of em.

  em [for emission measure], can be a float or an array of the same length as the temperature/density

  Parameters

    - temperature (float, list, ndarray) – the temperature(s) in K

    - eDensity (float, ndarray) – eDensity: electron density in \(\mathrm{cm^{-3}}\)

    - wvlRange (2 element list or ndarray) – wvlRange: range of wavelengths to consider, generally in angstroms

    - elementList (list) – elementList: list of elements to include, such as ‘fe’, ‘ne’, ‘s’

    - ionList (list) – ionList: list of ions to include, such as ‘fe_16’, ‘ne_10’

    - minAbund (float) – minAbund: minimum abundance (relative to H) to include

    - keepIons (bool) –

      keepIons: keep the ion instances used in the calculation

        should be used with caution otherwise the bunch instance can become quite large

    - em (float, list, ndarray) – em: the emission measure

    - abundance (str) –

      abuncance: the file name of the abuncance set to be used

        must be one in the $XUVTOP/abund directory

    - allLInes (bool) – allLines: whether or not to include unobserved lines

    - verbose (bool) – verbose: whether to allow certain print statements

  `convolve`(wavelength=None, filter=(<function gaussianR>, 1000.0), label=None, verbose=False)

    the first application of spectrum calculates the line intensities within the specified wavelength range and for set of ions specified

    wavelength will not be used if applied to ‘spectrum’ objects

    wavelength IS need for ‘bunch’ objects - in this case, the wavelength should not extend beyond the limits of the wvlRange used for the ‘bunch’ calculation

    Keyword Arguments

      - wavelength (‘int’, list) – if an int, the attribute ‘Wavelength’ is looked for otherwise, wavelength is used

      - filter (tuple) – first elements if one of the ChiantiPy.tools.filters object second element is the width appropriate to the filter

      - label (str) – if set, creates a Spectrum[label] attribute

      - verbose (bool) – if True, prints info to the terminal

## ChiantiPy.core.Spectrum module

class `ChiantiPy.core.Spectrum.``spectrum`(temperature, eDensity, wavelength, filter=(<function gaussianR>, 1000.0), label=None, elementList=None, ionList=None, minAbund=None, doLines=1, doContinuum=1, em=None, keepIons=0, abundance=None, verbose=0, allLines=1)

  Bases: `ChiantiPy.base._IonTrails.ionTrails`, `ChiantiPy.base._SpecTrails.specTrails`

  Calculate the emission spectrum as a function of temperature and density.

  one of the convenient things is that all of the instantiated ion classes, determined through such keywords as ‘elementList’, ‘ionList’, and ‘minAbund’ are kept in a dictionary self.IonInstances where self.IonInstances[‘mg_7’] is the class instance of ChiantiPy.core.ion for ‘mg_7’. All its methods and attributes are available.

  includes elemental abundances and ionization equilibria

  the set of abundances, a file in $XUVTOP/abundance, can be set with the keyword argument ‘abundanceName’

  temperature and density can be arrays but, unless the size of either is unity (1), the two must have the same size

  the returned spectrum will be convolved with a filter of the specified width on the specified wavelength array

  the default filter is gaussianR with a resolving power of 1000. Other filters, such as gaussian, box and lorentz, are available in ChiantiPy.tools.filters. When using the box filter, the width should equal the wavelength interval to keep the units of the continuum and line spectrum the same.

  Inherited methods include ‘intensityList’, ‘intensityRatio’ (between lines of different ions), ‘intensityRatioSave’ and ‘convolve’

  A selection of elements can be make with elementList a list containing the names of elements that are desired to be included, e.g., [‘fe’,’ni’]

  A selection of ions can be make with ionList containing the names of the desired lines in CHIANTI notation, i.e. C VI = c_6

  Both elementList and ionList can not be specified at the same time

  a minimum abundance can be specified so that the calculation can be speeded up by excluding elements with a low abundance. The default of minAbund is 1.e-6

  It is necessary to specify at least an elementList, an ionList, or a minAbund to select any ions for a spectrum calculation

  With solar photospheric abundances -

  setting minAbund = 1.e-4 will include H, He, C, O, Ne setting minAbund = 2.e-5 adds N, Mg, Si, S, Fe setting minAbund = 1.e-6 adds Na, Al, Ar, Ca, Ni

  Setting doLines = 0 will skip the calculation of spectral lines. Setting doContinuum =0 will skip the continuum calculation.

  Setting em [for emission measure] will multiply the spectrum at each temperature by the value of em.

  em [for emission measure] can be a float or an array of the same length as the temperature/density

  keepIons: set this to keep the ion instances that have been calculated in a dictionary self.IonInstances with the keywords being the CHIANTI-style ion names

  abundance: to select a particular set of abundances, set abundance to the name of a CHIANTI abundance file, without the ‘.abund’ suffix, e.g. ‘sun_photospheric_1998_grevesse’

  If set to a blank (‘’), a gui selection menu will popup and allow the selection of an set of abundances

  Parameters

    - temperature (float, list, ndarray) – the temperature(s) in K

    - eDensity (float, ndarray) – eDensity: electron density in \(\mathrm{cm^{-3}}\)

    - wavelength (list or ndarray) – wavelength: array of wavelengths, generally in Angstroms

    - elementList (list) – elementList: list of elements to include, such as ‘fe’, ‘ne’, ‘s’

    - ionList (list) – ionList: list of ions to include, such as ‘fe_16’, ‘ne_10’

    - minAbund (float) – minAbund: minimum abundance (relative to H) to include

    - keepIons (bool) –

      keepIons: keep the ion instances used in the calculation

        should be used with caution otherwise the bunch instance can become quite large

    - em (float, list, ndarray) – em: the emission measure

    - abundance (str) –

      abuncance: the file name of the abuncance set to be used

        must be one in the $XUVTOP/abund directory

    - allLInes (bool) – allLines: whether or not to include unobserved lines

    - verbose (bool) – verbose: whether to allow certain print statements

## Module contents

chianti.core - contains the main classes for ChiantiPy users.

This software is distributed under the terms of the ISC Software License that is found in the LICENSE file