gcfit.probabilities.likelihood_pulsar_orbital

gcfit.probabilities.likelihood_pulsar_orbital(model, pulsars, cluster_μ, coords, use_DM=False, *, mass_bin=None, hyperparams=False)

Compute the loglikelihood of binary pulsar orbital period derivatives.

Computes the log likelihood component of a cluster’s binary pulsar’s orbital period derivatives, evaluating the observed orbital timing solutions against the combined probability distributions of the clusters acceleration field, the proper-motion contribution and the galactic potential.

Parameters:

modelgcfit.FittableModel

Cluster model used to compute probability distribution.

pulsarsgcfit.core.data.Dataset

Pulsars dataset used to compute probability distribution and evaluate log likelihood.

cluster_μfloat

Total cluster proper motion, in mas/yr.

coords2-tuple of float

Cluster Galactic (Latitude, Longitude), in degrees.

use_DMbool, optional

Whether to use dispersion measure data in pulsar likelihoods.

mass_binint, optional

Index of model.mj mass bin to use in all calculations. If None (default), attempts to read ‘m’ from pulsars.mdata, else -1.

hyperparamsbool, optional

Not implemented.

Returns:

float

Log likelihood value.

See also

likelihood_pulsar_spin

Pulsar spin period likelihood.

gcfit.probabilities.pulsars

Module containing all pulsar prob. components.

Notes

The combined timing solutions for pulsars embedded in clusters, which is used alongside the model acceleration field to compute this likelihood, is given by the combination of components:

\[\left(\frac{\dot{P}}{P}\right)_{\rm{obs}} = \left(\frac{\dot{P}}{P}\right)_{\rm{int}} + \frac{a_{\rm{clust}}}{c} + \frac{a_{\rm{gal}}}{c} + \frac{\mu^2 D}{c}\]