FM

class sherpa.astro.optical.FM(name='fm')[source]

Bases: sherpa.models.model.RegriddableModel1D

UV extinction curve: Fitzpatrick and Massa 1988.

The UV extinction is calculated using [1]. This model is intended to be used to modify another model (e.g. by multiplying the two together). It is for use when the independent axis is in Angstrom.

ebv

E(B-V)

x0

Position of the Drude bump.

width

Width of the Drude bump.

c1

The intercept of the linear term.

c2

The slope of the linear term.

c3

Normalization of the Drude bump.

c4

Normalization of the FUV curvature.

See also

CCM, LMC, Seaton, SM, SMC, XGAL

Notes

When evaluated on a binned grid, the lower-edges of the bins are used for the calculation.

References

[1]Fitzpatrick and Massa 1988 http://adsabs.harvard.edu/abs/1988ApJ…328..734F

Attributes Summary

thawedparhardmaxes
thawedparhardmins
thawedparmaxes
thawedparmins
thawedpars

Methods Summary

apply(outer, *otherargs, **otherkwargs)
calc(p, x[, xhi]) Evaluate the model on a grid.
get_center()
guess(dep, *args, **kwargs) Set an initial guess for the parameter values.
regrid(*arrays)
reset()
set_center(*args, **kwargs)
startup() Called before a model may be evaluated multiple times.
teardown() Called after a model may be evaluated multiple times.

Attributes Documentation

thawedparhardmaxes
thawedparhardmins
thawedparmaxes
thawedparmins
thawedpars

Methods Documentation

apply(outer, *otherargs, **otherkwargs)
calc(p, x, xhi=None, **kwargs)[source]

Evaluate the model on a grid.

Parameters:
  • p (sequence of numbers) – The parameter values to use. The order matches the pars field.
  • *args – The model grid. The values can be scalar or arrays, and the number depends on the dimensionality of the model and whether it is being evaluated over an integrated grid or at a point (or points).
get_center()
guess(dep, *args, **kwargs)

Set an initial guess for the parameter values.

Attempt to set the parameter values, and ranges, for the model to match the data values. This is intended as a rough guess, so it is expected that the model is only evaluated a small number of times, if at all.

regrid(*arrays)
reset()
set_center(*args, **kwargs)
startup()

Called before a model may be evaluated multiple times.

See also

teardown()

teardown()

Called after a model may be evaluated multiple times.

See also

setup()