Converting Spectral-Energy-Distributions (SEDs)

In Astronomy, SEDs can have different styles. The style effects the units and sometimes multiplies the y -axis with a power-law depending on the x -axis. But to compare findings we have to transform to a single style. This function helps you to transform between sed-styles. Here are example sed-styles A , B , C , and D showing the differential flux of Crab, and the integral sensitivity of Fermi-LAT.

A	B

A = {
    "x_energy_in_eV": 1e6,
    "y_inverse_energy_in_eV": 624150907446.0763,  # one erg
    "y_inverse_area_in_m2": 1e-4,
    "y_inverse_time_in_s": 1.0,
    "y_scale_energy_in_eV": 624150907446.0763,  # one erg
    "y_scale_energy_power": 2.0,
}

B = {
    "x_energy_in_eV": 1e9,
    "y_inverse_energy_in_eV": 1e9,
    "y_inverse_area_in_m2": 1.0,
    "y_inverse_time_in_s": 1.0,
    "y_scale_energy_in_eV": 1e9,
    "y_scale_energy_power": 0.0,
}

C	D

C = {
    "x_energy_in_eV": 1,
    "y_inverse_energy_in_eV": 1,
    "y_inverse_area_in_m2": 1,
    "y_inverse_time_in_s": 1.0,
    "y_scale_energy_in_eV": 1,
    "y_scale_energy_power": 2.7,
}

D = {
    "x_energy_in_eV": 1e9,
    "y_inverse_energy_in_eV": 1e12,
    "y_inverse_area_in_m2": 1e-4,
    "y_inverse_time_in_s": 1.0,
    "y_scale_energy_in_eV": 1e12,
    "y_scale_energy_power": 2.0,
}

Function

Transform the numeric values in the arrays x -axis, and y -axis from style A to B.

import spectral_energy_distribution_units as sed
x_B, y_B = sed.convert_units_with_style(x=x_A, y=y_A, input_style=A, target_style=B)

Find also a function for the style-dictionaries A and B being unpacked:

x_B, y_B = sed.convert_units(x=x_A, y=y_A, x_energy_in_eV=... )

Install

pip install spectral_energy_distribution_units

Example

See unit-tests ./spectral_energy_distribution_units/tests/test_convert.py to reproduce the upper figures A , B , C , and D.