pynbody.analysis.luminosity.SSPTable

pynbody.analysis.luminosity.SSPTable#

class pynbody.analysis.luminosity.SSPTable(ages, metallicities, magnitudes, case_insensitive=False, ignore_bands=None, is_ab_system=False)[source]#

Bases: object

An SSP table for interpolating magnitudes from stellar populations

Attributes:
bands

List of bandpasses available in this table

Methods

__call__(snapshot, band)

Interpolate the magnitude for a given snapshot and bandpass

get_central_wavelength(band)

Get the estimated central wavelength of a bandpass

get_flux_normalization(band)

Get the normalization factor for converting relative magnitudes to fluxes

get_spectral_density_normalization(band)

Get the normalization factor for converting absolute magnitudes to spectral density

interpolate(ages, metallicities, band)

Interpolate the magnitude for a given age, metallicity and bandpass
__init__(ages, metallicities, magnitudes, case_insensitive=False, ignore_bands=None, is_ab_system=False)[source]#

Initialise an SSP table

Parameters:

  • ages (array-like) – Array of ages in log10 years, length N

  • metallicities (array-like) – Array of log10 metal mass fractions, length M

  • magnitudes (dict[str, array-like]) – Dictionary of bandpass names to 2D arrays of magnitudes, size N x M

  • case_insensitive (bool, optional) – If True, the bandpass names are treated as case-insensitive.

  • ignore_bands (list[str], optional) – List of bandpasses to ignore. These bandpasses will not be available in the table.

  • is_ab_system (bool, optional) – If True, the magnitudes are in the AB system. If False, the magnitudes are in the Vega system.

property bands#

List of bandpasses available in this table

get_central_wavelength(band)[source]#

Get the estimated central wavelength of a bandpass

The values are approximate, based on the tabulated central wavelengths from CMD. If you use a different bandpass set, you may wish to override this method. It is used by the pynbody.plot.stars.render() routine to estimate the central wavelength of a bandpass for the purposes of estimating dust extinction.

Parameters:

band (str) – Bandpass name

Returns:

Central wavelength in Angstroms

Return type:

float

get_flux_normalization(band)[source]#

Get the normalization factor for converting relative magnitudes to fluxes

The normalization factor is the flux of a star with a magnitude of 0 in the given bandpass. Currently, this is only implemented for AB-calibrated systems, where the normalization factor is 3631 Jy.

get_spectral_density_normalization(band)[source]#

Get the normalization factor for converting absolute magnitudes to spectral density

This uses the flux normalization and then (as per definition of absolute magnitude) considers the source to be at a distance of 10 pc. The output units are power per unit frequency (or, eqivalently, energy).

interpolate(ages, metallicities, band)[source]#

Interpolate the magnitude for a given age, metallicity and bandpass

Parameters:

  • age (float or array-like) – Age in log10 years

  • metallicities (float or array-like) – Metallicity in log10 mass fraction

  • band (str) – Bandpass name

Returns:

Magnitude(s) per solar mass interpolated from the SSP table

Return type:

float or array-like

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