Constants Namespace Reference

Functions
constexpr double	amu ()
constexpr double	AU ()
constexpr double	c ()
constexpr double	EinsteinALya ()
constexpr double	EinsteinASpinFlip ()
constexpr double	h ()
constexpr double	k ()
constexpr double	lambdaIon ()
constexpr double	lambdaLya ()
constexpr double	lambdaSpinFlip ()
constexpr double	Lsun ()
constexpr double	Melectron ()
constexpr double	Mproton ()
constexpr double	Msun ()
constexpr double	NA ()
constexpr double	pc ()
constexpr double	Qelectron ()
constexpr double	sigmaThomson ()
constexpr double	Tcmb ()
constexpr double	year ()

Detailed Description

The Constants namespace offers functions that return the value of physical constants or units used in astronomy. Other parts of the code should use these functions rather than defining the values locally. All functions are defined inline as constexpr to avoid runtime overhead.

Function Documentation

amu()

constexpr double Constants::amu ( )

constexpr

This function returns the mass of an atomic mass unit (1/12 of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest).

AU()

constexpr double Constants::AU ( )

constexpr

This function returns the distance of one astronomical unit.

c()

constexpr double Constants::c ( )

constexpr

This function returns the speed of light $c$.

EinsteinALya()

constexpr double Constants::EinsteinALya ( )

constexpr

This function returns the Einstein A-coefficient of the Lyman-alpha transition.

EinsteinASpinFlip()

constexpr double Constants::EinsteinASpinFlip ( )

constexpr

This function returns the Einstein A-coefficient of the hydrogen spinflip transition.

h()

constexpr double Constants::h ( )

constexpr

This function returns Planck's constant $h$.

k()

constexpr double Constants::k ( )

constexpr

This function returns the Boltzmann constant $k$.

lambdaIon()

constexpr double Constants::lambdaIon ( )

constexpr

This function returns the ionization wavelength of atomic hydrogen.

lambdaLya()

constexpr double Constants::lambdaLya ( )

constexpr

This function returns the central wavelength of the hydrogen Lyman-alpha transition.

lambdaSpinFlip()

constexpr double Constants::lambdaSpinFlip ( )

constexpr

This function returns the central wavelength of the hydrogen spinflip transition.

Lsun()

constexpr double Constants::Lsun ( )

constexpr

This function returns the solar bolometric luminosity without neutrino radiation.

Melectron()

constexpr double Constants::Melectron ( )

constexpr

This function returns the rest mass of the electron.

Mproton()

constexpr double Constants::Mproton ( )

constexpr

This function returns the rest mass of the proton.

Msun()

constexpr double Constants::Msun ( )

constexpr

This function returns the solar mass.

NA()

constexpr double Constants::NA ( )

constexpr

This function returns the Avogadro constant $N_{\text{A}}$, i.e. the number of atoms or molecules in one mole of a given substance.

pc()

constexpr double Constants::pc ( )

constexpr

This function returns the distance of one parsec.

Qelectron()

constexpr double Constants::Qelectron ( )

constexpr

This function returns the electric charge of an electron in coulombs, which is equivalent to the value of 1 eV in joules.

sigmaThomson()

constexpr double Constants::sigmaThomson ( )

constexpr

This function returns the Thomson cross section for an electron.

Tcmb()

constexpr double Constants::Tcmb ( )

constexpr

This function returns the average temperature of the cosmic microwave background (CMB) in the Local Universe.

year()

constexpr double Constants::year ( )

constexpr

This function returns the length of a Julian year in seconds. A Julian year has exactly 365.25 days of exactly 86400 seconds each.