VCG04

class dust_extinction.parameter_averages.VCG04(*args, meta=None, name=None, **kwargs)[source]

Bases: BaseExtRvModel

Valencic, Clayton, & Gordon (2004) Milky Way R(V) dependent model

Parameters:
Rv: float

R(V) = A(V)/E(B-V) = total-to-selective extinction

Raises:
InputParameterError

Input Rv values outside of defined range

Notes

From Valencic, Clayton, & Gordon (2004, ApJ, 616, 912) Including erratum: 2014, ApJ, 793, 66

This model applies to the UV spectral region all the way to 912 A. This model was not derived for the optical or NIR.

Example showing V04 curves for a range of R(V) values.

import numpy as np
import matplotlib.pyplot as plt
import astropy.units as u

from dust_extinction.parameter_averages import VCG04

fig, ax = plt.subplots()

# generate the curves and plot them
x = np.arange(3.3,8.0, 0.1)/u.micron

Rvs = ['2.0','3.0','4.0','5.0','6.0']
for cur_Rv in Rvs:
   ext_model = VCG04(Rv=cur_Rv)
   ax.plot(x,ext_model(x),label='R(V) = ' + str(cur_Rv))

ax.set_xlabel(r'$x$ [$\mu m^{-1}$]')
ax.set_ylabel(r'$A(x)/A(V)$')

ax.legend(loc='best')
plt.show()

(Source code, png, hires.png, pdf)

../_images/dust_extinction-parameter_averages-VCG04-1.png

Attributes Summary

Rv_range

x_range

Methods Summary

evaluate(in_x, Rv)

VCG04 function

Attributes Documentation

Rv_range = [2.0, 6.0]
x_range = [3.3, 8.0]

Methods Documentation

static evaluate(in_x, Rv)[source]

VCG04 function

Parameters:
in_x: float

expects either x in units of wavelengths or frequency or assumes wavelengths in wavenumbers [1/micron] internally wavenumbers are used

Returns:
axav: np array (float)

A(x)/A(V) extinction curve [mag]

Raises:
ValueError

Input x values outside of defined range