MetinSa / Cosmoglobe

The Cosmoglobe Sky model. A Python package for producing astrophysical sky simulations directly from Commander results.

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cosmoglobe is a python package that interfaces the Cosmoglobe Sky Model with Commander outputs for the purpose of producing astrophysical sky maps.

Features

See the documentation for amore comprehensive guide.

Initialize Sky Model from Chain:

import cosmoglobe

chain = cosmoglobe.get_test_chain() # Downloads a minimal Commander chainfile.
model = cosmoglobe.model_from_chain(chain, nside=256)

Simulate the sky at 150 GHz in units of MJy/sr, smoothed to 40 arcmin with a gaussian beam:

import astropy.units as u

emission = model(150*u.GHz, fwhm=40*u.arcmin, output_unit="MJy/sr")

Integrate over a bandpass:

import numpy as np
import healpy as hp
import matplotlib.pyplot as plt

# Reading in WMAP K-band bandpass profile.
bandpass_frequencies, bandpass_weights = np.loadtxt(wmap_bandpass.txt, unpack=True)

# The units of the detector must be specified even if the bandpass is pre-normalized.
bandpass_weights *= u.Unit("K_RJ") # Specify K_RJ or K_CMB
bandpass_frequencies *= u.GHz

model.remove_dipole() # Remove the dipole from the CMB component
emission = model(
    freqs=bandpass_frequencies, 
    weights=bandpass_weights, 
    fwhm=0.8*u.deg, 
    output_unit="mK_RJ",
)

hp.mollview(emission[0], hist="norm") # Plotting the intensity
plt.show()

Installation

cosmoglobe can be installed via pip

pip install cosmoglobe

Funding

This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreements No 776282 (COMPET-4; BeyondPlanck), 772253 (ERC; bits2cosmology) and 819478 (ERC; Cosmoglobe).

License

GNU GPLv3