Bases: astropy.modeling.Fittable2DModel
Two dimensional Sersic surface brightness profile.
Parameters: | amplitude : float
r_eff : float
n : float
x_0 : float, optional
y_0 : float, optional
ellip : float, optional
theta : float, optional
|
---|---|
Other Parameters: | |
fixed : a dict
tied : dict
bounds : dict eqcons : list
ineqcons : list
|
See also
Notes
Model formula:
I(x,y) = I(r) = I_e\exp\left[-b_n\left(\frac{r}{r_{e}}\right)^{(1/n)}-1\right]
The constant b_n is defined such that r_e contains half the total luminosity, and can be solved for numerically.
\Gamma(2n) = 2\gamma (b_n,2n)
References
[R8] | http://ned.ipac.caltech.edu/level5/March05/Graham/Graham2.html |
Examples
import numpy as np
from astropy.modeling.models import Sersic2D
import matplotlib.pyplot as plt
x,y = np.meshgrid(np.arange(100), np.arange(100))
mod = Sersic2D(amplitude = 1, r_eff = 25, n=4, x_0=50, y_0=50,
ellip=.5, theta=-1)
img = mod(x, y)
log_img = np.log10(img)
plt.figure()
plt.imshow(log_img, origin='lower', interpolation='nearest',
vmin=-1, vmax=2)
plt.xlabel('x')
plt.ylabel('y')
cbar = plt.colorbar()
cbar.set_label('Log Brightness', rotation=270, labelpad=25)
cbar.set_ticks([-1, 0, 1, 2], update_ticks=True)
plt.show()
(Source code, png, hires.png, pdf)
Attributes Summary
amplitude | |
ellip | |
n | |
param_names | |
r_eff | |
theta | |
x_0 | |
y_0 |
Methods Summary
evaluate(x, y, amplitude, r_eff, n, x_0, ...) | Two dimensional Sersic profile function. |
Attributes Documentation
Methods Documentation
Two dimensional Sersic profile function.