ModifiedBlackBodyRealization

class pysm3.ModifiedBlackBodyRealization(largescale_alm, freq_ref, amplitude_modulation_temp_alm, amplitude_modulation_pol_alm, small_scale_cl, largescale_alm_mbb_index, small_scale_cl_mbb_index, largescale_alm_mbb_temperature, small_scale_cl_mbb_temperature, nside, galplane_fix=None, seeds=None, synalm_lmax=None, has_polarization=True, map_dist=None)[source] [edit on github]

Bases: ModifiedBlackBody

Modified Black Body model with stochastic small scales

Small scale fluctuations in the templates, the spectral index and the black body temperature are generated on the fly based on the input power spectra, then added to deterministic large scales.

In order to reproduce d10, set seeds to [8192,777,888] and synalm_max to 16384, either by passing arguments to the class constructor or by creating a configuration file based on the d11 parameters in data/presets.cfg uncommenting the final section labelled “Configuration for reproducing d10”

Parameters:
largescale_alm, largescale_alm_mbb_index, largescale_alm_mbb_temperature: `pathlib.Path`

Paths to the Alm expansion of the dust template IQU maps, the spectral index and the dust black-body temperature. Templates are assumed to be in logpoltens formalism, units refer to the unit of the maps when transformed back to IQU maps.

freq_ref: Quantity or string

Reference frequencies at which the intensity and polarization templates are defined. They should be a astropy Quantity object or a string (e.g. “1500 MHz”) compatible with GHz.

amplitude_modulation_temp_alm, amplitude_modulation_pol_alm: `pathlib.Path`

Paths to the Alm expansion of the modulation maps used to rescale the small scales to make them more un-uniform, they are derived from highly smoothed input emission.

small_scale_cl, small_scale_cl_mbb_index, small_scale_cl_mbb_temperature: `pathlib.Path`

Paths to the power spectra of the small scale fluctuations for logpoltens iqu and the black body spectral index and temperature

nside: int

Resolution parameter at which this model is to be calculated.

galplane_fix: `pathlib.Path`

Set to None to skip the galactic plane fix in order to save some memory and computing time. Used to replace the galactic emission inside the GAL 070 Planck mask to a precomputed map. This is used to avoid excess power in the full sky spectra due to the generated small scales being too strong on the galactic plane. By default in d9,d10,d11 we use the input GNILC map with a resolution of 21.8’

seeds: list of ints

List of seeds used for generating the small scales, first is used for the template, the second for the spectral index, the third for the black body temperature. In order to reproduce d10, set them to [8192,777,888], if None, it uses random seeds.

synalm_lmax: int

Lmax of Synalm for small scales generation, by default it is 3*nside-1, with a maximum of 16384. In order to reproduce d10, you need to set it to 16834.

map_dist: Map distribution

Unsupported, this class doesn’t support MPI Parallelization

Methods Summary

draw_realization([synalm_lmax, seeds])

Methods Documentation

draw_realization(synalm_lmax=None, seeds=None)[source] [edit on github]