H2SSSCAM Modules

Functions to perform basic calculations required to create spectograms.

class h2ssscam.BaseCalc.BaseCalc(constant: h2ssscam.Constants.Constants, _dv_phys: astropy.units.quantity.Quantity = None, _dv_tot: astropy.units.quantity.Quantity = None, _tau: astropy.units.quantity.Quantity = None, _tau_tot: astropy.units.quantity.Quantity = None, _siglu: astropy.units.quantity.Quantity = None)

Bases: object

blackbody(lam, temp, unit)

Compute the photon radiance of a blackbody at a given temperature.

Parameters:

  • lam (astropy.units.Quantity) – Wavelength array (e.g., in Å or m).

  • temp (astropy.units.Quantity) – Blackbody temperature (e.g., in K).

  • unit (astropy.units.Quantity) – Continuum units or CGS units.

Returns:

Photon radiance [ph / (cm2 s sr Å)].

Return type:

astropy.units.Quantity

boltzmann(Ntot, ju, jl, lam, T)

Partitioning via Boltzmann distribution.

Parameters:

  • Ntot (astropy.units.Quantity) – Total column density.

  • ju (int) – Upper rotational quantum numbers.

  • jl (int) – Lower rotational quantum numbers.

  • lam (astropy.units.Quantity) – Transition wavelength.

  • T (astropy.units.Quantity) – Gas temperature.

Returns:

Column density in lower level (cm^-2).

Return type:

astropy.units.Quantity

calc_abs_rate(I0, tau, tau_all, unit)

Compute absorbed rate per line.

Parameters:

  • I0 (array) – Incident continuum intensity.

  • tau (array) – Line optical depths.

  • tau_all (array) – Total optical depth across lines.

  • unit (astropy.units.Quantity) – Continuum units or CGS units.

Returns:

Absorption rates per line.

Return type:

array

Notes

Implements Eq. 12-13 (McJunkin et al. 2016).

calc_flu(ju, jl, lamlu, Aul)

Calculate oscillator strength f_lu from Einstein A coefficient.

Parameters:

  • ju (array-like) – Upper rotation levels

  • jl (array-like) – Lower rotation levels

  • lamlu (astropy.units.Quantity) – Transition wavelengths.

  • Aul (astropy.units.Quantity) – Einstein A coefficients.

Returns:

Oscillator strengths.

Return type:

array

Notes

  • Implements Eq. 1 (McJunkin et al. 2016).

  • Original code includes multiplicity (2s + 1); McJunkin et al. 2016 does not.

calc_nvj(ntot, T)

Compute level populations N_vJ for all v,J.

Parameters:

  • ntot (astropy.units.Quantity) – Total column density.

  • T (astropy.units.Quantity) – Temperature.

  • vmax (int, optional) – Max vibrational and rotational levels., by default VMAX

  • jmax (int, optional) – Max vibrational and rotational levels., by default JMAX

Returns:

Populations per level.

Return type:

array

Notes

Implements Eq. 8 (McJunkin et al. 2016).

calc_spec(lam, lamlu, Atot, dv, flux_per_trans, source, unit, dopp_v=0)

Build emergent spectrum from line profiles + continuum.

Parameters:

  • lam (astropy.units.Quantity) – Wavelength grid.

  • lamlu (astropy.units.Quantity) – Line wavelengths.

  • Atot (astropy.units.Quantity) – Damping constants.

  • dv (astropy.units.Quantity) – Doppler width.

  • flux_per_trans (array) – Flux per transition.

  • source (array) – Continuum source function.

  • unit (astropy.units.Quantity) – Continuum units or CGS units.

  • dopp_v (astropy.units.Quantity, optional) – Doppler Velocity.

Returns:

  • array – Wavelength grid.

  • array – Normalized emission-only spectrum.

  • array – Normalized total spectrum including continuum.

constant: Constants
property dv_phys
property dv_tot
reset_parameters()

Clean calculated and stored values

siglu(lam=None, hih2_lamlu=None, hih2_Atot=None, hih2_flu=None)
tau(hih2_N=None)
property tau_tot
uv_continuum(lam, unit)

Empirical UV continuum function.

Parameters:

  • lam (astropy.units.Quantity) – Wavelength grid.

  • unit (astropy.units.Quantity) – Continuum units or CGS units.

Returns:

Continuum intensity.

Return type:

array

Notes

Original fit comes from Draine (1978).

h2ssscam.plotting_funcs.plot_spectrum(wavelengths, intensity, xmin=None, xmax=None, ymin=None, ymax=None, units=None, ylabel=None, title='Spectrum', show=False)

Plots intensity over wavelength.

Parameters:

  • wavelengths (array) – Grid of equally spaced wavelength points.

  • intensity (array) – Grid of corresponding intensity points.

  • xmin (float, optional) – Minimum value on the x-axis, by default None

  • xmax (float, optional) – Maximum value on the x-axis, by default None

  • ymin (float, optional) – Minimum value on the y-axis, by default None

  • ymax (float, optional) – aximum value on the y-axis, by default None

  • units (astropy.units.Quantity, optional) – Chosen units for intensity, by default None

  • ylabel (str, optional) – Label on the y-axis, by default None

  • title (regexp, optional) – Title of the Plot, by default r”Spectrum”

  • show (bool, optional) – Option to display plot, by default False

Raises:

ValueError –

class h2ssscam.Constants.Constants(user_config_path: str | None = None)

Bases: object

read_config_files(user_config_path)

Loads default config file from the package and user’s config file if specified

Parameters:

user_config_path (str) – Path to the config file

Return type:

configparser

save_config_file(output_path)

Save config file with currently used parameters value

Parameters:

output_path (str) – Output file path

value(parameter_name, parameter_type=<class 'float'>)

Load a parameter value from the configparser and transform it to float if required

Parameters:

  • parameter_name (str) – Name of a parameter

  • parameter_type (type, optional) – Transform parameter value into this type; configparser stores everything as strings. Only float is implemented, and by default float

Return type:

str | float

Raises:

ValueError – If parameter is not defined in the config file