convert a map from ecliptic coordinates to galactic coordinates

Question

I have a fits map mollview projection but in ecliptic coordinates. I want to convert it to galactic coordinates. Please suggest a code so that I can visualize it in galactic coordinates.

import numpy as np
import matplotlib.pyplot as plt
import healpy as hp
from pixell import enmap, reproject, utils
from matplotlib import cm

path = "/home/masroor/fazl/"
imap = enmap.read_map(path + 
"act_planck_dr5.01_s08s18_AA_f150_daynight_map.fits")[0]
try:
    imap
exce pt NameError:
    imap = None
def eshow(x,**kwargs): 
    ''' Define a function to help us plot the maps neatly '''
    plots = enplot.get_plots(x, **kwargs)
    enplot.show(plots, method = "ipython")


smap_healpix = reproject.healpix_from_enmap(imap, lmax=6000, 
nside=128)
lonra = np.sort(imap.box()[:, 1])/utils.degree
latra = np.sort(imap.box()[:, 0])/utils.degree
rang = 300

ecliptic_to_galactic_matrix = hp.Rotator(coord=['G', 'E'], 
deg=True).mat

galactic_map = hp.mollview(smap_healpix,min = -rang, max = 
rang,coord='CE', rot=ecliptic_to_galactic_matrix, xsize=800, 
title='Galactic Coordinates', cmap=cm.get_cmap('RdYlBu'))

hp.graticule()

this is the code I used but I don't think this is in galactic coordinates

Answer 1

if you just want to plot in Galactic, just do:

hp.mollview(m_ecliptic, coord=["E", "G"])

if you want an actual map array in Galactic coordinates:

ecl2gal = hp.Rotator(coord=['G', 'E'])
m_galactic = ecl2gal.rotate_map_alms(m_ecliptic)

for more details and an example you can take a look at this tutorial https://www.zonca.dev/posts/2021-03-11-rotate-maps-healpy