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transit_2D

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transit_2D#

luas.exoplanet.transit_fns.transit_2D(p: Any, x_l: Array, x_t: Array) → Array[source]#

Uses jax.vmap on the transit_light_curve function to generate a 2D JAXArray of transit light curves for multiple wavelengths simultaneously.

This is just meant to be a simple example for generating multiple simultaneous light curves in wavelength, it should be easy to modify for different limb darkening parameterisations, etc. See the package jaxoplanet to see the range of currently implemented light curve models.

Note

Unlike transit_light_curve, input limb darkening parameters are assumed to follow the Kipping (2013) parameterisation and are converted to standard limb darkening coefficients. Also assumed that the transit depth d = rho^2 is being input which is then converted to radius ratio values for transit_light_curve.

>>> from luas.exoplanet import transit_2D
>>> import jax.numpy as jnp
>>> N_l = 16 # Number of wavelength channels
>>> par = {
>>> ... "T0":0.,                    # Central transit time (days)
>>> ... "P":3.4,                    # Period (days)
>>> ... "a":8.2,                    # Semi-major axis to stellar ratio (aka a/R*)
>>> ... "d":0.01*np.ones(N_l),      # Transit depth (aka (Rp/R*)^2 or rho^2)
>>> ... "b":0.5,                    # Impact parameter
>>> ... # Kipping (2013) limb darkening parameterisation is used
>>> ... "q1":0.36*np.ones(N_l),     # First quadratic limb darkening coefficient for each wv
>>> ... "q2":0.416*np.ones(N_l),    # Second quadratic limb darkening coefficient for each wv
>>> ... "Foot":1.*np.ones(N_l),     # Baseline flux out of transit for each wv
>>> ... "Tgrad":0.*np.ones(N_l),    # Gradient in baseline flux for each wv (hrs^-1)
>>> }
>>> x_l = jnp.linspace(4000, 7000, N_l)
>>> x_t = jnp.linspace(-0.1, 0.1, 100)
>>> flux = transit_2D(par, x_l, x_t)
Parameters:

  • par (PyTree) – The transit parameters stored in a PyTree/dictionary (see example above).

  • x_l (JAXArray) – Array of wavelengths, not used but included for compatibility with luas.GP.

  • x_t (JAXArray) – Array of times to calculate the light curve at.

Returns:

2D array of flux values in a wavelength by time grid of shape (N_l, N_t).

Return type:

JAXArray

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