vac_to_air

specutils.utils.wcs_utils.vac_to_air(wavelength, method='Morton2000', co2=None)[source]

Converts vacuum to air wavelengths using different methods.

Parameters:
wavelengthQuantity object (number or sequence)

Vacuum wavelengths with an astropy.unit.

methodstr, optional

One of the methods in refraction_index(), default is ‘Morton2000’.

co2number, optional

Atmospheric CO2 concentration in ppm. Only used for method=’Ciddor1996’. If not given, a default concentration of 450 ppm is used.

Returns:
air_wavelengthQuantity object (number or sequence)

Air wavelengths with the same unit as wavelength.