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'$A(x)/A(V)$') # for 2nd x-axis with lambda values axis_xs = np.array([0.12, 0.15, 0.2, 0.3]) new_ticks = 1 / axis_xs new_ticks_labels = ["%.2f" % z for z in axis_xs] tax = ax.twiny() tax.set_xlim(ax.get_xlim()) tax.set_xticks(new_ticks) tax.set_xticklabels(new_ticks_labels) tax.set_xlabel(r"$\lambda$ [$\mu$m]") ax.legend(loc='best') plt.show()
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Source code
,png
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)Attributes Summary
Methods Summary
evaluate
(x, Rv)VCG04 function
Attributes Documentation
- Rv_range = [2.0, 6.0]¶
- x_range = [3.3, 8.0]¶
Methods Documentation
- static evaluate(x, Rv)[source]¶
VCG04 function
- Parameters:
- 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