# petitRADTRANS.nat_cst¶

## Module Contents¶

### Functions¶

 b(T, nu) Returns the Planck function $$B_{\nu}(T)$$ in units of guillot_global(P, kappa_IR, gamma, grav, T_int, T_equ) Returns a temperature array, in units of K, get_PHOENIX_spec(temperature) Returns a matrix where the first column is the wavelength in cm get_PHOENIX_spec_rad(temperature) Returns a matrix where the first column is the wavelength in cm running_mean(x, N) guillot_global_ret(P, delta, gamma, T_int, T_equ) guillot_modif(P, delta, gamma, T_int, T_equ, ptrans, alpha) make_press_temp(rad_trans_params) make_press_temp_iso(rad_trans_params)

### Attributes¶

Returns the Planck function $$B_{\nu}(T)$$ in units of $$\rm erg/s/cm^2/Hz/steradian$$.

Args:
T (float):

Temperature in K.

nu:

numpy array containing the frequency in Hz.

petitRADTRANS.nat_cst.guillot_global(P, kappa_IR, gamma, grav, T_int, T_equ)

Returns a temperature array, in units of K, of the same dimensions as the pressure P (in bar). For this the temperature model of Guillot (2010) is used (his Equation 29).

Args:
P:

numpy array of floats, containing the input pressure in bars.

kappa_IR (float):

The infrared opacity in units of $$\rm cm^2/s$$.

gamma (float):

The ratio between the visual and infrated opacity.

grav (float):

The planetary surface gravity in units of $$\rm cm/s^2$$.

T_int (float):

The planetary internal temperature (in units of K).

T_equ (float):

The planetary equilibrium temperature (in units of K).

Returns a matrix where the first column is the wavelength in cm and the second is the stellar flux $$F_\nu$$ in units of $$\rm erg/cm^2/s/Hz$$, at the surface of the star. The spectra are PHOENIX models from (Husser et al. 2013), the spectral grid used here was described in van Boekel et al. (2012).

Args:
temperature (float):

stellar effective temperature in K.

Returns a matrix where the first column is the wavelength in cm and the second is the stellar flux $$F_\nu$$ in units of $$\rm erg/cm^2/s/Hz$$, at the surface of the star. The spectra are PHOENIX models from (Husser et al. 2013), the spectral grid used here was described in van Boekel et al. (2012).

UPDATE: It also returns a float that is the corresponding estimate of the stellar radius.

Args:
temperature (float):

stellar effective temperature in K.