gravelamps.lensing.o3point

Isolated Point Mass Lensing Functions used within LVK O3 (full + O3a) Papers.

Written by Eungwang Seo 2020

NOTE FROM DEVELOPERS: Included as legacy code, these functions are designed to replicate specifically those analyses, and are superceded by Gravelamps’ point mass lensing functions. Consequent to this, they will not be actively updated. They were written to be functional for version 2.1, subsequent versions do not guarantee that this will remain functional.

To be used, the user must specify a location for the lookuptable.h5 file that can be found: https://git.ligo.org/eungwang.seo/bilby_pmlens/-/blob/master/src/lookuptable.h5

Functions

load_table(table_location)	Input:
magnification(source_position, mode)	Input:
time_delay(source_position)	Input:
frequency_to_dimensionless_frequency(frequency_array, ...)	Input;
amplification_factor_geometric(...)	Input:
amplification_factor_wave_lookup(...)	Input:
amplification_factor(frequency_array, source_position, ...)	Input:

Module Contents

gravelamps.lensing.o3point.load_table(table_location)

Input:

table_location - string containing filepath of the lookup table of amplification factor

values

Function loads in the lookup table from the specified location and generates arrays containing the higher and lower source position values from it.

gravelamps.lensing.o3point.magnification(source_position, mode)

Input:

source_position - dimensionless displacement from optical axis mode - flag for whether to give the positive or negative magnification

Output:

mag - Value of the magnification

Function computes the mangification for the isolated point mass lens model

gravelamps.lensing.o3point.time_delay(source_position)

Input:

source_position - dimensionless displacement from optical axis

Output:

delay - dimensionless time delay for the image

Function computes the dimensionless time delay for the image.

gravelamps.lensing.o3point.frequency_to_dimensionless_frequency(frequency_array, log_lens_mass)

Input;

frequency_array - Array containing frequencies to be converted log_lens_mass - Log of the lens mass

Ouput:

dimensionless_frequency_array - Dimensionless equivalent array

Function converts an array of frequnecy values to the equivalent dimensionless frequencies

gravelamps.lensing.o3point.amplification_factor_geometric(dimensionless_frequency, source_position)

Input:

dimensionless_frequency - Dimensionless form of frequency being amplified source_position - Dimensionless displacement from the optical axis

Output:

amplification_factor - Value of the amplification factor

Calculates the geometric optics amplification factor value

gravelamps.lensing.o3point.amplification_factor_wave_lookup(dimensionless_frequency, source_position, position_index_step, data_array)

Input:

dimensionless_frequency - Dimensionless form of frequency being amplified source_position - Dimensionless displacement from the optical axis position_index_step - Step size for the source position data_array - Array of the data for the amplification factor

Output:

amplification_factor - Value of the amplification factor from the lookup table

Function computes the value of the amplification factor using the lookup table. It does this as a correction to the geometric factor calculation

gravelamps.lensing.o3point.amplification_factor(frequency_array, source_position, log_lens_mass, **kwargs)

Input:

frequency_array - Array of frequencies to be amplified source_position - Dimensionless displacement from the optical axis log_lens_mass - Log of the mass of the lensing object

Output:

amplification_factor - Values of the amplification factor

Function computes the values of the amplification factor from the lookup table.