add_colours
Combine red and blue galaxy intrinsic alignment signals based on color fractions
File |
intrinsic_alignments/add_colours/add_colours.py |
Attribution |
Simon Samuroff |
URL |
This module combines intrinsic alignment signals from red and blue galaxy populations to compute the total IA signal for a galaxy sample with mixed colors. It assumes that separate IA power spectra have been computed for red and blue galaxies.
The module uses color fractions and separate amplitude/evolution parameters for red and blue populations to linearly combine the II and GI power spectra. Cross-terms between red and blue populations are included assuming they follow the geometric mean of the individual population spectra.
Assumptions
Separate IA signals computed for red and blue galaxy populations
Galaxy sample has known red/blue fractions and amplitude/evolution parameters
Setup Parameters
Name |
Type |
Default |
Description |
|---|---|---|---|
catalogue |
str |
Section name containing galaxy color fraction information |
Input values
Section |
Name |
Type |
Default |
Description |
|---|---|---|---|---|
catalogue_section |
red_fraction |
real |
Fraction of red galaxies in the sample |
|
intrinsic_alignment_parameters |
A_red |
real |
IA amplitude for red galaxies |
|
A_blue |
real |
IA amplitude for blue galaxies |
||
alpha_red |
real |
Redshift evolution parameter for red galaxies |
||
alpha_blue |
real |
Redshift evolution parameter for blue galaxies |
||
z |
real 1d |
Redshift values for IA power spectra |
||
k_h |
real 1d |
Wavenumber values in h/Mpc |
||
P_II_red |
real 2d |
Intrinsic-intrinsic power spectrum for red galaxies |
||
P_II_blue |
real 2d |
Intrinsic-intrinsic power spectrum for blue galaxies |
||
P_GI_red |
real 2d |
Galaxy-intrinsic cross power spectrum for red galaxies |
||
P_GI_blue |
real 2d |
Galaxy-intrinsic cross power spectrum for blue galaxies |
Output values
Section |
Name |
Type |
Description |
|---|---|---|---|
intrinsic_alignment_parameters |
z |
real 1d |
Redshift values for combined IA power spectra |
k_h |
real 1d |
Wavenumber values in h/Mpc |
|
P_II |
real 2d |
Combined intrinsic-intrinsic power spectrum |
|
P_GI |
real 2d |
Combined galaxy-intrinsic cross power spectrum |