physics.py API

bh_molecule.physics

Attributes

Classes

BHModel

BH spectroscopy model. See Also Physics explainer

Attributes

K2eV = spc.Boltzmann / spc.eV instance-attribute

K2wn = spc.Boltzmann / (spc.h * spc.c * 100) instance-attribute

M_BH = 11.81 instance-attribute

g_as = 8 instance-attribute

v00_wl = v00_wl_df instance-attribute

wn2Hz = spc.c * 100.0 instance-attribute

Functions

A_coeff(v: int, N2: int, N1: int) -> float staticmethod

Einstein :math:A_{ul} for :math:A\,^1\Pi \rightarrow X\,^1\Sigma^+ line.

Parameters:

Name	Type	Description	Default
v	int	Upper vibrational level :math:v'.	required
N2	int	Upper rotational level :math:N_2 (A-state).	required
N1	int	Lower rotational level :math:N_1 (X-state).	required

Returns:

Type	Description
float	:math:A_{ul} in s⁻¹.
See Also [Physics explainer — A coefficient](../phys.md#a-coeff)

energy(v: int, N: int, c: MolecularConstants) -> float staticmethod

Level term value :math:E(v,N) [cm⁻¹].

Parameters:

Name	Type	Description	Default
v	int	Vibrational quantum number (:math:v').	required
N	int	Rotational quantum number (:math:N); for singlets, :math:J=N.	required
c	MolecularConstants	State constants (:math:T_e, \omega_e, \omega_e x_e, \omega_e y_e, B_e, \alpha_e, D_e, \beta_e).	required

Returns:

Type	Description
float	Term value :math:E(v,N) in cm⁻¹.
See Also [Physics explainer — energy](../phys.md#energy)

full_fit_model(x: np.ndarray, C: float, T_rot: float, dx: float, w_inst: float, base: float, I_R7: float, I_R8: float) -> np.ndarray

Composite forward model near 433 nm: BH Q-branch + two fixed Gaussians + baseline.

Parameters:

Name	Type	Description	Default
x	ndarray	Wavelength grid [nm].	required
C	float	Overall population/intensity scale for the BH Q-branch.	required
T_rot	float	Rotational temperature [K].	required
dx	float	Grid shift [nm].	required
w_inst	float	Instrumental Gaussian FWHM [nm].	required
base	float	Constant baseline.	required
I_R7	float	Amplitude of auxiliary line at :math:\lambda_{R7}.	required
I_R8	float	Amplitude of auxiliary line at :math:\lambda_{R8}.	required

Returns:

Type	Description
ndarray	Model evaluated on x.
See Also [Physics explainer — full fit model](../phys.md#full-fit-model)

line_profile(x, wl, w_inst, T)

Gaussian line profile in wavelength with Doppler ⊕ instrumental FWHM.

Parameters:

Name	Type	Description	Default
x	array_like	Wavelength grid [nm].	required
wl	float	Line center wavelength [nm].	required
w_inst	float	Instrumental FWHM [nm] (Gaussian).	required
T	float	Translational/kinetic temperature [K] for Doppler broadening.	required

Returns:

Type	Description
ndarray	Normalized profile sampled on x (area ≈ 1).
See Also [Physics explainer — line profile](../phys.md#line-profile)

spectrum(x: np.ndarray, C: float, T_rot: float, w_inst: float, T_tra: float, branch: Branch, v_max: int = 2, N2_max: int = 22) -> np.ndarray

Branch spectrum on a wavelength grid; sums Gaussian lines over P/Q/R.

Parameters:

Name	Type	Description	Default
x	ndarray	Wavelength grid [nm].	required
C	float	Population scale factor.	required
T_rot	float	Rotational temperature [K].	required
w_inst	float	Instrumental Gaussian FWHM [nm].	required
T_tra	float	Translational temperature [K] for Doppler.	required
branch	Branch	Rotational branch to synthesize.	required
v_max	int	Highest upper vibrational level :math:v' (inclusive).	2
N2_max	int	Highest upper rotational level :math:N_2 (inclusive).	22

Returns:

Type	Description
ndarray	Spectrum on x (same shape), arbitrary units.
See Also [Physics explainer — spectrum](../phys.md#spectrum)

Branch

Bases: Enum

Attributes

P = 'P' class-attribute instance-attribute

Q = 'Q' class-attribute instance-attribute

R = 'R' class-attribute instance-attribute