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species.phot package

species.phot package#

Submodules#

species.phot.syn_phot module#

Module with functionalities for calculating synthetic photometry.

class species.phot.syn_phot.SyntheticPhotometry(filter_name: str, zero_point: float | None = None)[source]#

Bases: object

Class for calculating synthetic photometry from a spectrum and also for converting between magnitudes and fluxes. Any filter from the SVO Filter Profile Service will be automatically downloaded and added to the database. Also the detector type (energy- or photon-counting) will be fetched. For a photon-counting detector, an additional wavelength factor is included in the integral for calculating the synthetic photometry, although typically the impact of the factor on the calculated flux is negligible. It is also important to note that by default the magnitude of Vega is set to 0.03 for all filters. The value can be adjusted in the configuration file.

Parameters:

  • filter_name (str) –

    Filter name by which the profile is stored in database. Any filter from the SVO Filter Profile Service will be automatically downloaded and added to the database.

  • zero_point (float, None) –

    Zero-point flux (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)) for filter_name. This flux is equalized to the magnitude of Vega, which by default is set to 0.03 for all filters. The value can be adjusted in the configuration file. By default, the argument of zero_point is set to None, in which case the zero point is calculated internally. The zero point can be accessed through zero_point attribute from instance of SyntheticPhotometry.

Returns:

None

Return type:

NoneType

calc_zero_point() → float | float64[source]#

Internal function for calculating the zero point of the provided filter_name. The zero point is here defined as the flux of Vega, which by default is set to a magnitude of 0.03 for all filters.

Returns:

Zero-point flux (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)).

Return type:

float

flux_to_magnitude(flux: float, error: float | ndarray | None = None, parallax: Tuple[float, float | None] | Tuple[ndarray, ndarray | None] | None = None, distance: Tuple[float, float | None] | Tuple[ndarray, ndarray | None] | None = None) → Tuple[Tuple[float, float | None] | Tuple[ndarray, ndarray | None], Tuple[float | None, float | None] | Tuple[ndarray | None, ndarray | None]][source]#

Function for converting a flux into a magnitude.

Parameters:

  • flux (float, np.ndarray) – Flux (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)).

  • error (float, np.ndarray, None) – Uncertainty (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)). Not used if set to None.

  • parallax (tuple(float, float), , tuple(np.ndarray, np.ndarray), None) – Parallax and uncertainty (mas). The returned absolute magnitude is set to None in case parallax and distance are set to None. The error is not propagated into the error on the absolute magnitude in case the parallax uncertainty is set to None, for example parallax=(10., None).

  • distance (tuple(float, float), tuple(np.ndarray, np.ndarray), None) – Distance and uncertainty (pc). The returned absolute magnitude is set to None in case distance and parallax are set to None. The error is not propagated into the error on the absolute magnitude in case the distance uncertainty is set to None, for example distance=(20., None). This parameter is ignored if the parallax parameter is used.

Returns:

  • tuple(float, float), tuple(np.ndarray, np.ndarray) – Apparent magnitude and uncertainty.

  • tuple(float, float), tuple(np.ndarray, np.ndarray) – Absolute magnitude and uncertainty.

magnitude_to_flux(magnitude: float, error: float | None = None, zp_flux: float | None = None) → Tuple[float | float32 | float64, float | float32 | float64 | None][source]#

Function for converting a magnitude to a flux.

Parameters:

  • magnitude (float) – Magnitude.

  • error (float, None) – Error on the magnitude. Not used if set to None.

  • zp_flux (float, None) – DEPRECATED: Zero-point flux (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)). This parameter is deprecated and will be removed in a future release. Please use the zero_point parameter of the constructor of SyntheticPhotometry instead. By default, the zero point is calculated internally and stored as the zero_point attribute of an instance from SyntheticPhotometry.

Returns:

  • float – Flux (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)).

  • float, None – Error (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)). The returned value is None if the argument of error is None.

spectrum_to_flux(wavelength: ndarray, flux: ndarray, error: ndarray | None = None, threshold: float | None = 0.01) → Tuple[float | float32 | float64, float | float32 | float64 | None][source]#

Function for calculating the average flux from a spectrum and a filter profile. The uncertainty is propagated by sampling 200 random values from the error distributions.

Parameters:

  • wavelength (np.ndarray) – Wavelength points (um).

  • flux (np.ndarray) – Flux (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)).

  • error (np.ndarray, None) – Uncertainty (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)). Not used if set to None.

  • threshold (float, None) – Transmission threshold (value between 0 and 1). If the minimum transmission value is larger than the threshold, a NaN is returned. This will happen if the input spectrum does not cover the full wavelength range of the filter profile. The parameter is not used if set to None (default: 0.01).

Returns:

  • float – Average flux (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)).

  • float, None – Uncertainty (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)).

spectrum_to_magnitude(wavelength: ndarray, flux: ndarray, error: ndarray | List[ndarray] | None = None, parallax: Tuple[float, float | None] | None = None, distance: Tuple[float, float | None] | None = None, threshold: float | None = 0.01) → Tuple[Tuple[float, float | None], Tuple[float | None, float | None] | None][source]#

Function for calculating the apparent and absolute magnitude from a spectrum and a filter profile. The uncertainty is propagated by sampling 200 random values from the error distributions.

Parameters:

  • wavelength (np.ndarray) – Wavelength points (um).

  • flux (np.ndarray) – Flux (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)).

  • error (np.ndarray, list(np.ndarray), None) – Uncertainty (\(\mathrm{W}\) \(\mathrm{m}^{-2}\) \(\mu\mathrm{m}^{-1}\)).

  • parallax (tuple(float, float), None) – Parallax and uncertainty (mas). No absolute magnitude is calculated if set to None. No error on the absolute magnitude is calculated if the error parameter is set to None.

  • distance (tuple(float, float), None) – Distance and uncertainty (pc). No absolute magnitude is calculated if set to None. No error on the absolute magnitude is calculated if the error parameter is set to None. This parameter is ignored if the parallax parameter is used.

  • threshold (float, None) – Transmission threshold (value between 0 and 1). If the minimum transmission value is larger than the threshold, a NaN is returned. This will happen if the input spectrum does not cover the full wavelength range of the filter profile. The parameter is not used if set to None (default: 0.01).

Returns:

  • tuple(float, float) – Apparent magnitude and uncertainty.

  • tuple(float, float) – Absolute magnitude and uncertainty.

Module contents#

Contents