CMBDipole

class pysm3.CMBDipole(nside: int, amp, T_cmb, dip_lon, dip_lat, map_dist=None, quadrupole_correction: bool = False)

Bases: object

Simulate the CMB dipole anisotropy as a full-sky HEALPix map.

The dipole is modeled as a temperature fluctuation due to the observer’s motion with respect to the CMB rest frame, following the relativistic Doppler effect.

Parameters:

nsideint

HEALPix NSIDE parameter for the output map (dimensionless).

ampfloat

Amplitude of the dipole in micro-Kelvin (uK_CMB).

T_cmbfloat

CMB monopole temperature in Kelvin (K_CMB).

dip_lonfloat

Galactic longitude of the dipole direction, in degrees (deg).

dip_latfloat

Galactic latitude of the dipole direction, in degrees (deg).

Returns:

dipole_mapastropy.units.Quantity

Full-sky HEALPix map (array) of the dipole temperature anisotropy in Kelvin.

Notes

The dipole amplitude is calculated as:

ΔT/T = (v/c) * cos(θ)

where θ is the angle between the dipole direction and the line of sight.

References

For the best-fit parameters, see Table 1 of “Planck intermediate results. LVII. Joint Planck LFI and HFI data processing” https://arxiv.org/pdf/2007.04997.pdf

Methods Summary

get_emission(freqs[, weights])

Return the dipole emission map, integrating over the bandpass if needed.

Methods Documentation

get_emission(freqs: Annotated[Quantity, Unit('GHz')], weights=None) → Annotated[Quantity, Unit('uK_RJ')]

Return the dipole emission map, integrating over the bandpass if needed.

Parameters:

freqsQuantity

Frequency or array of frequencies (for bandpass integration).

weightsarray-like, optional

Integration weights for the bandpass.

Returns:

dipole_mapastropy.units.Quantity

Full-sky HEALPix map (array) of the dipole temperature anisotropy in uK_RJ.