Package cosmolopy :: Module constants

Module constants

Various constants used by CosmoloPy code.

Unit abreviations are appended to the name, but powers are not specified. For instance, the gravitational constant has units "Mpc^3 msun^-1 s^-2", but is called "G_const_Mpc_Msun_s".

Most of these numbers are from google calculator.

Constants are:

G_const_Mpc_Msun_s: Gravitational constant in Mpc^3 msun^-1 s^-2
Gyr_s: Gigayear in s
H100_s: 100 km s^-1 Mpc^-1 in s^-1
M_sun_g: Solar mass in grams.
Mpc_cm: Megaparsec in cm
Mpc_km: Megaparsec in km
Myr_s: Megayear in s
alpha_B_cm_s_1e4: hydrogen recombination coefficient at T=10^4 K
amu_g: atomic mass unit in g
angstrom_cm: Angstrom in cm
c_light_Mpc_Gyr: Speed of light in Mpc/Gyr
c_light_Mpc_s: Speed of light in Mpc/s
c_light_cm_s: Speed of light in Mpc/s (from google calculator)
lambda_Lya_0: Central wavelength of H Lyman-alpha in Angstroms
lambda_NY_0: Central wavelength of an NV doublet in Angstroms
m_H_g: mass of a hydrogen atom in g
m_He_g: mass of a helium atom in g
m_p_g: mass of a proton in g
pc_cm: Parsec in cm
sigma_T_cm: Thomson cross section in Mpc^2
sigma_T_cm: Thomson cross section in cm^2
yr_s: a year in s

Variables
	doc = `' pc_cm: Parsec in cm\n Mpc_cm: Megaparsec in cm\n Mp...`
	pc_cm = `3.08568025e+18`
	Mpc_cm = `3.08568025e+24`
	Mpc_km = `3.08568025e+19`
	angstrom_cm = `1e-08`
	yr_s = `31536000.0`
	Myr_s = `3.1536e+13`
	Gyr_s = `3.1536e+16`
	amu_g = `1.66053886e-24`
	m_p_g = `1.67262158e-24`
	m_H_g = `1.67372353855e-24`
	m_He_g = `6.64647616211e-24`
	M_sun_g = `1.98892e+33`
	c_light_cm_s = `29979245800.0`
	c_light_Mpc_s = `9.71560348808e-15`
	c_light_Mpc_Gyr = `306.3912716`
	H100_s = `3.24077648681e-18`
	G_const_Mpc_Msun_s = `4.51737014558e-48`
	lambda_Lya_0 = `1215.67`
	lambda_NV_0 = `1240.81`
	alpha_B_cm_s_1e4 = `2.59e-13`
	sigma_T_cm = `6.6524586e-25`
	sigma_T_Mpc = `6.98683261505e-74`
	__package__ = `None`

Variables Details

doc

Value:

'''  pc_cm: Parsec in cm
  Mpc_cm: Megaparsec in cm
  Mpc_km: Megaparsec in km
  angstrom_cm: Angstrom in cm
  yr_s: a year in s
  Myr_s: Megayear in s
  Gyr_s: Gigayear in s
  amu_g: atomic mass unit in g
...