public class Distances extends Object
The following parameters are used:
For a flat universe, omegaM
+omegaLambda
=1
The terms and formulae used here are taken from the paper by D.W.Hogg, Distance measures in cosmology, astro-ph/9905116 v4 (2000).
Modifier and Type | Field and Description |
---|---|
static double |
METRE_PER_PARSEC
Number of metres in a parsec.
|
static double |
SEC_PER_YEAR
Number of seconds in a year.
|
static double |
SPEED_OF_LIGHT
Speed of light in m/s.
|
Modifier and Type | Method and Description |
---|---|
static double |
angularDiameterDistance(double z,
double H0,
double omegaM,
double omegaLambda)
Angular diameter distance.
|
static double |
comovingDistanceL(double z,
double H0,
double omegaM,
double omegaLambda)
Line-of-sight comoving distance.
|
static double |
comovingDistanceT(double z,
double H0,
double omegaM,
double omegaLambda)
Transverse comoving distance.
|
static double |
comovingVolume(double z,
double H0,
double omegaM,
double omegaLambda)
Comoving volume.
|
static double |
lookbackTime(double z,
double H0,
double omegaM,
double omegaLambda)
Lookback time.
|
static double |
luminosityDistance(double z,
double H0,
double omegaM,
double omegaLambda)
Luminosity distance.
|
static double |
MpcToM(double distMpc)
Converts from MegaParsecs to metres.
|
static double |
mToMpc(double distM)
Converts from metres to MegaParsecs.
|
static double |
zToAge(double z)
Quick and dirty function for converting from redshift to time.
|
static double |
zToDist(double z)
Quick and dirty function for converting from redshift to distance.
|
public static final double SPEED_OF_LIGHT
public static final double METRE_PER_PARSEC
public static final double SEC_PER_YEAR
public static double MpcToM(double distMpc)
distMpc
- distance in Mpcpublic static double mToMpc(double distM)
distM
- distance in mpublic static double zToDist(double z)
Warning: this makes some reasonable assumptions about the cosmology and returns the luminosity distance. It is only intended for approximate use. If you care about the details, use one of the more specific functions here.
z
- redshiftpublic static double zToAge(double z)
Warning: this makes some reasonable assumptions about the cosmology. It is only intended for approximate use. If you care about the details use one of the more specific functions here.
z
- redshiftz
in Gyrpublic static double comovingDistanceL(double z, double H0, double omegaM, double omegaLambda)
z
- redshiftH0
- Hubble constant in km/sec/MpcomegaM
- density ratio of the universeomegaLambda
- normalised cosmological constantpublic static double comovingDistanceT(double z, double H0, double omegaM, double omegaLambda)
z
- redshiftH0
- Hubble constant in km/sec/MpcomegaM
- density ratio of the universeomegaLambda
- normalised cosmological constantpublic static double angularDiameterDistance(double z, double H0, double omegaM, double omegaLambda)
z
- redshiftH0
- Hubble constant in km/sec/MpcomegaM
- density ratio of the universeomegaLambda
- normalised cosmological constantpublic static double luminosityDistance(double z, double H0, double omegaM, double omegaLambda)
z
- redshiftH0
- Hubble constant in km/sec/MpcomegaM
- density ratio of the universeomegaLambda
- normalised cosmological constantpublic static double lookbackTime(double z, double H0, double omegaM, double omegaLambda)
z
were emitted.z
- redshiftH0
- Hubble constant in km/sec/MpcomegaM
- density ratio of the universeomegaLambda
- normalised cosmological constantpublic static double comovingVolume(double z, double H0, double omegaM, double omegaLambda)
z
.z
- redshiftH0
- Hubble constant in km/sec/MpcomegaM
- density ratio of the universeomegaLambda
- normalised cosmological constantCopyright © 2024 Central Laboratory of the Research Councils. All Rights Reserved.