M14¶

class dust_extinction.parameter_averages.M14(*args, meta=None, name=None, **kwargs)[source]¶

Bases: BaseExtRvModel

Maiz Apellaniz et al (2014) Milky Way & LMC R(V) dependent model

Parameters:

R5495: float: R5495 = A(5485)/E(4405-5495) Spectral equivalent to photometric R(V), standard value is 3.1

Raises:

InputParameterError: Input Rv values outside of defined range

Notes

M14 R5485-dependent model

From Maiz Apellaniz et al. (2014, A&A, 564, 63), following structure of IDL code provided in paper appendix

The published UV extinction curve is identical to Clayton, Cardelli, and Mathis (1989, CCM). Forcing the optical section to match smoothly with CCM introduces a non-physical feature at high values of R5495 around 3.9 inverse microns; see section 5 in Maiz Apellaniz et al. (2014) for more discussion. For that reason, we provide the M14 model only through 3.3 inverse microns, the limit of the optical in CCM.

R5495 = A(5485)/E(4405-5495) Spectral equivalent to photometric R(V), standard value is 3.1

Example showing M14 curves for a range of R5495 values.

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

from dust_extinction.parameter_averages import M14

fig, ax = plt.subplots()

# temp model to get the correct x range
text_model = M14()

# generate the curves and plot them
x = np.arange(text_model.x_range[0],
              text_model.x_range[1],0.1)/u.micron

Rvs = ['2.0','3.1','4.0','5.0','6.0']
for cur_Rv in Rvs:
   ext_model = M14(Rv=cur_Rv)
   ax.plot(x,ext_model(x),label='R(V) = ' + str(cur_Rv))

# for 2nd x-axis with lambda values
axis_xs = np.array([0.3, 0.5, 1.0, 2.0])
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.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-M14-1.png

Attributes Summary

`Rv_range`
`x_range`

Methods Summary

evaluate(x, Rv)

M14 function

Attributes Documentation

Rv_range = [2.0, 6.0]¶

x_range = [0.3, 3.3]¶

Methods Documentation

static evaluate(x, Rv)[source]¶

M14 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

Navigation

M14¶