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Given the following text description, write Python code to implement the functionality described below step by step
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Description:
 Extinction
Step1:  As always, let's do imports and initialize a logger and a new bundle.
Step2:  First we'll define the system parameters
Step3:  And then create three light curve datasets at the same times, but in different passbands
Step4:  Now we'll set some atmosphere and limb-darkening options
Step5:  And flip the extinction constraint so we can provide E(B-V).
Step6:  For comparison, we'll run a model without extinction
Step7:  and then another model with extinction
Step8:  Lastly, we'll convert the model fluxes into magnitudes and format the figures.
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Python Code:
#!pip install -I "phoebe>=2.3,<2.4"
Explanation: Extinction: B-K Binary
In this example, we'll reproduce Figures 1 and 2 in the extinction release paper (Jones et al. 2020).
"Let us begin with a rather extreme case, a synthetic binary  comprised  of  a  hot,  B-type  main  sequence  star(M=6.5 Msol,Teff=17000  K,  and R=4.2 Rsol)  anda  cool  K-type  giant  (M=1.8 Msol,Teff=4000 K, and R=39.5 Rsol)vin a 1000 day orbit -- a  system  where, while the temperature difference is large, the luminosities are similar." (Jones et al. 2020)
<img src="jones+20_fig1.png" alt="Figure 1" width="800px"/>
<img src="jones+20_fig2.png" alt="Figure 2" width="400px"/>
Setup
Let's first make sure we have the latest version of PHOEBE 2.3 installed (uncomment this line if running in an online notebook session such as colab).
End of explanation
import matplotlib
matplotlib.rcParams['text.usetex'] = True
matplotlib.rcParams['pdf.fonttype'] = 42
matplotlib.rcParams['ps.fonttype'] = 42
matplotlib.rcParams['mathtext.fontset'] = 'stix'
matplotlib.rcParams['font.family'] = 'STIXGeneral'
from matplotlib import gridspec
%matplotlib inline
import phoebe
from phoebe import u # units
import numpy as np
import matplotlib.pyplot as plt
logger = phoebe.logger('error')
b = phoebe.default_binary()
Explanation: As always, let's do imports and initialize a logger and a new bundle.
End of explanation
b.set_value('period', component='binary', value=1000.0*u.d)
b.set_value('teff', component='primary', value=17000*u.K)
b.set_value('teff', component='secondary', value=4000*u.K)
b.set_value('requiv', component='primary', value=4.22173036*u.solRad)
b.set_value('requiv', component='secondary', value=40.732435*u.solRad)
b.flip_constraint('mass@primary', solve_for='sma@binary')
b.set_value('mass', component='primary', value=6.5*u.solMass)
b.flip_constraint('mass@secondary', solve_for='q')
b.set_value('mass', component='secondary', value=1.9145*u.solMass)
Explanation: First we'll define the system parameters
End of explanation
times = phoebe.linspace(-20, 20, 101)
b.add_dataset('lc', times=times, dataset='B', passband="Johnson:B")
b.add_dataset('lc', times=times, dataset='R', passband="Cousins:R")
b.add_dataset('lc', times=times, dataset='KEP', passband="Kepler:mean")
Explanation: And then create three light curve datasets at the same times, but in different passbands
End of explanation
b.set_value_all('atm', 'ck2004')
b.set_value_all('gravb_bol', 0.0)
b.set_value_all('ld_mode_bol', 'manual')
b.set_value_all('ld_func_bol', 'linear')
b.set_value_all('ld_coeffs_bol', [0.0])
Explanation: Now we'll set some atmosphere and limb-darkening options
End of explanation
b.flip_constraint('ebv', solve_for='Av')
Explanation: And flip the extinction constraint so we can provide E(B-V).
End of explanation
b.set_value('ebv', 0.0)
b.run_compute(distortion_method='rotstar', irrad_method='none', model='noext')
Explanation: For comparison, we'll run a model without extinction
End of explanation
b.set_value('ebv', 1.0)
b.run_compute(distortion_method='rotstar', irrad_method='none', model='ext')
Explanation: and then another model with extinction
End of explanation
Bextmags=-2.5*np.log10(b['value@fluxes@B@ext@model'])
Bnoextmags=-2.5*np.log10(b['value@fluxes@B@noext@model'])
Bextmags_norm=Bextmags-Bextmags.min()+1
Bnoextmags_norm=Bnoextmags-Bnoextmags.min()+1
Bresid=Bextmags_norm-Bnoextmags_norm
Rextmags=-2.5*np.log10(b['value@fluxes@R@ext@model'])
Rnoextmags=-2.5*np.log10(b['value@fluxes@R@noext@model'])
Rextmags_norm=Rextmags-Rextmags.min()+1
Rnoextmags_norm=Rnoextmags-Rnoextmags.min()+1
Rresid=Rextmags_norm-Rnoextmags_norm
fig=plt.figure(figsize=(12,6))
gs=gridspec.GridSpec(2,2,height_ratios=[4,1],width_ratios=[1,1])
ax=plt.subplot(gs[0,0])
ax.plot(b['value@times@B@noext@model']/1000,Bnoextmags_norm,color='k',linestyle="--")
ax.plot(b['value@times@B@ext@model']/1000,Bextmags_norm,color='k',linestyle="-")
ax.set_ylabel('Magnitude')
ax.set_xticklabels([])
ax.set_xlim([-0.02,0.02])
ax.set_ylim([3.5,0.8])
ax.set_title('(a) Johnson B')
ax2=plt.subplot(gs[0,1])
ax2.plot(b['value@times@R@noext@model']/1000,Rnoextmags_norm,color='k',linestyle="--")
ax2.plot(b['value@times@R@ext@model']/1000,Rextmags_norm,color='k',linestyle="-")
ax2.set_ylabel('Magnitude')
ax2.set_xticklabels([])
ax2.set_xlim([-0.02,0.02])
ax2.set_ylim([3.5,0.8])
ax2.set_title('(b) Cousins Rc')
ax_1=plt.subplot(gs[1,0])
ax_1.plot(b['value@times@B@noext@model']/1000,Bresid,color='k',linestyle='-')
ax_1.set_ylabel(r'$\Delta m$')
ax_1.set_xlabel('Phase')
ax_1.set_xlim([-0.02,0.02])
ax_1.set_ylim([0.05,-0.3])
ax_1.axhline(y=0., linestyle='dashed',color='k',linewidth=0.5)
ax2_1=plt.subplot(gs[1,1])
ax2_1.plot(b['value@times@R@noext@model']/1000,Rresid,color='k',linestyle='-')
ax2_1.set_ylabel(r'$\Delta m$')
ax2_1.set_xlabel('Phase')
ax2_1.set_xlim([-0.02,0.02])
ax2_1.set_ylim([0.05,-0.3])
ax2_1.axhline(y=0., linestyle='dashed',color='k',linewidth=0.5)
plt.tight_layout()
fig.canvas.draw()
KEPextmags=-2.5*np.log10(b['value@fluxes@KEP@ext@model'])
KEPnoextmags=-2.5*np.log10(b['value@fluxes@KEP@noext@model'])
KEPextmags_norm=KEPextmags-KEPextmags.min()+1
KEPnoextmags_norm=KEPnoextmags-KEPnoextmags.min()+1
KEPresid=KEPextmags_norm-KEPnoextmags_norm
fig=plt.figure(figsize=(6,6))
gs=gridspec.GridSpec(2,1,height_ratios=[4,1])
ax=plt.subplot(gs[0])
ax.plot(b['value@times@KEP@noext@model']/1000,KEPnoextmags_norm,color='k',linestyle="--")
ax.plot(b['value@times@KEP@ext@model']/1000,KEPextmags_norm,color='k',linestyle="-")
ax.set_ylabel('Magnitude')
ax.set_xticklabels([])
ax.set_xlim([-0.02,0.02])
ax.set_ylim([3.5,0.8])
ax.set_title('Kepler K')
ax_1=plt.subplot(gs[1])
ax_1.plot(b['value@times@KEP@noext@model']/1000,KEPresid,color='k',linestyle='-')
ax_1.set_ylabel(r'$\Delta m$')
ax_1.set_xlabel('Phase')
ax_1.set_xlim([-0.02,0.02])
ax_1.set_ylim([0.05,-0.3])
ax_1.axhline(y=0., linestyle='dashed',color='k',linewidth=0.5)
plt.tight_layout()
fig.canvas.draw()
Explanation: Lastly, we'll convert the model fluxes into magnitudes and format the figures.
End of explanation
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