Included Cosmology Realizations

A number of preloaded cosmologies are available from analyses using the WMAP and Planck satellite data. The full list of the predefined cosmologies is given by cosmology.realizations.available and summarized below:

Name	Source	H0	Om	Flat
|WMAP1|	Spergel et al. 2003	72.0	0.257	Yes
|WMAP3|	Spergel et al. 2007	70.1	0.276	Yes
|WMAP5|	Komatsu et al. 2009	70.2	0.277	Yes
|WMAP7|	Komatsu et al. 2011	70.4	0.272	Yes
|WMAP9|	Hinshaw et al. 2013	69.3	0.287	Yes
|Planck13|	Planck Collab 2013, Paper XVI	67.8	0.307	Yes
|Planck15|	Planck Collab 2015, Paper XIII	67.7	0.307	Yes
|Planck18|	Planck Collab 2018, Paper VI	67.7	0.310	Yes

Currently, all are instances of |FlatLambdaCDM|. More details about exactly where each set of parameters comes from are available in the docstring for each object and described below:

>>> from astropy.cosmology import WMAP7
>>> print(WMAP7.__doc__)
WMAP7 instance of FlatLambdaCDM cosmology
(from Komatsu et al. 2011, ApJS, 192, 18, doi: 10.1088/0067-0049/192/2/18.
 Table 1 (WMAP + BAO + H0 ML).)

Planck 2018

The parameters are from Planck Collaboration (2020) Table 2 (TT, TE, EE + lowE + lensing + BAO) [P18].

Note

The Planck 2018 paper includes massive neutrinos in Om0 but the Planck18 object includes them in m_nu instead for consistency. Hence, the Om0 value in Planck18 differs slightly from the Planck 2018 paper but represents the same cosmological model.

Metadata

Oc0	Omega cold dark matter at z=0
n	Density perturbation spectral index
sigma8	Density perturbation amplitude
tau	Ionisation optical depth
z_reion	Redshift of hydrogen reionisation
t0	Age of the universe in Gyr
reference	Reference for the parameters

References

[P18]

Planck Collaboration, et. al. (2020). Planck 2018 results. VI. Cosmological parameters. Astronomy & Astrophysics, 641, A6. https://ui.adsabs.harvard.edu/abs/2020A%26A…641A…6P/abstract

Planck 2015

Parameters are from Planck Collaboration (2016) Paper XIII, Table 4 (TT, TE, EE + lowP + lensing + ext) [P15].

Metadata

Oc0	Omega cold dark matter at z=0
n	Density perturbation spectral index
sigma8	Density perturbation amplitude
tau	Ionisation optical depth
z_reion	Redshift of hydrogen reionisation
t0	Age of the universe in Gyr
reference	Reference for the parameters

References

[P15]

Planck Collaboration, et. al. (2016). Planck 2015 results. XIII. Cosmological parameters. Astronomy & Astrophysics, 594, A13. https://ui.adsabs.harvard.edu/abs/2016A%26A…594A..13P/abstract

Planck 2013

Parameters are from Planck Collaboration (2014) Paper XVI, Table 5 (Planck + WP + highL + BAO) [P13].

Metadata

Oc0	Omega cold dark matter at z=0
n	Density perturbation spectral index
sigma8	Density perturbation amplitude
tau	Ionisation optical depth
z_reion	Redshift of hydrogen reionisation
t0	Age of the universe in Gyr
reference	Reference for the parameters

References

[P13]

Planck Collaboration, et. al. (2014). Planck 2013 results. XVI. Cosmological parameters. Astronomy & Astrophysics, 571, A16. https://ui.adsabs.harvard.edu/abs/2014A%26A…571A..16P/abstract

WMAP 9 Year

Parameters are from Hinshaw et al. (2013) Table 4 (WMAP9 + eCMB + BAO + H0) [WM9].

Metadata

Oc0	Omega cold dark matter at z=0
n	Density perturbation spectral index
sigma8	Density perturbation amplitude
tau	Ionisation optical depth
z_reion	Redshift of hydrogen reionisation
t0	Age of the universe in Gyr
reference	Reference for the parameters

References

[WM9]

Hinshaw, G., Larson, D., Komatsu, E., Spergel, D., Bennett, C., Dunkley, J., Nolta, M., Halpern, M., Hill, R., Odegard, N., Page, L., Smith, K., Weiland, J., Gold, B., Jarosik, N., Kogut, A., Limon, M., Meyer, S., Tucker, G., Wollack, E., & Wright, E. (2013). Nine-year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results. The Astrophysical Journal Supplement, 208(2), 19. https://ui.adsabs.harvard.edu/abs/2014A%26A…571A..16P/abstract

WMAP 7 Year

Parameters are from Komatsu et al. (2011) Table 1 (WMAP + BAO + H0 ML) [WM7].

Metadata

Oc0	Omega cold dark matter at z=0
n	Density perturbation spectral index
sigma8	Density perturbation amplitude
tau	Ionisation optical depth
z_reion	Redshift of hydrogen reionisation
t0	Age of the universe in Gyr
reference	Reference for the parameters

References

[WM7]

Komatsu, E., Smith, K., Dunkley, J., Bennett, C., Gold, B., Hinshaw, G., Jarosik, N., Larson, D., Nolta, M., Page, L., Spergel, D., Halpern, M., Hill, R., Kogut, A., Limon, M., Meyer, S., Odegard, N., Tucker, G., Weiland, J., Wollack, E., & Wright, E. (2011). Seven-year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation. The Astrophysical Journal Supplement, 192(2), 18. https://ui.adsabs.harvard.edu/abs/2011ApJS..192…18K/abstract

WMAP 5 Year

Parameters are from Komatsu et al. (2009) Table 1 (WMAP + BAO + SN ML) [WM5].

Metadata

Oc0	Omega cold dark matter at z=0
n	Density perturbation spectral index
sigma8	Density perturbation amplitude
tau	Ionisation optical depth
z_reion	Redshift of hydrogen reionisation
t0	Age of the universe in Gyr
reference	Reference for the parameters

References

[WM5]

Komatsu, E., Dunkley, J., Nolta, M., Bennett, C., Gold, B., Hinshaw, G., Jarosik, N., Larson, D., Limon, M., Page, L., Spergel, D., Halpern, M., Hill, R., Kogut, A., Meyer, S., Tucker, G., Weiland, J., Wollack, E., & Wright, E. (2009). Five-Year Wilkinson Microwave Anisotropy Probe Observations: Cosmological Interpretation. The Astrophysical Journal Supplement, 180(2), 330-376. https://ui.adsabs.harvard.edu/abs/2009ApJS..180..330K/abstract

WMAP 3 Year

Parameters are from Spergel et al. (2007) Table 6 (WMAP + SNGold) [WM3], obtained from https://lambda.gsfc.nasa.gov/product/map/dr2/params/lcdm_wmap_sngold.cfm. Tcmb0 and Neff are the standard values as also used for |WMAP5|, |WMAP7|, |WMAP9|.

Note

Pending WMAP team approval and subject to change.

Metadata

Oc0	Omega cold dark matter at z=0
n	Density perturbation spectral index
sigma8	Density perturbation amplitude
tau	Ionisation optical depth
z_reion	Redshift of hydrogen reionisation
t0	Age of the universe in Gyr
reference	Reference for the parameters

References

[WM3]

Spergel, D., Bean, R., Doré, O., Nolta, M., Bennett, C., Dunkley, J., Hinshaw, G., Jarosik, N., Komatsu, E., Page, L., Peiris, H., Verde, L., Halpern, M., Hill, R., Kogut, A., Limon, M., Meyer, S., Odegard, N., Tucker, G., Weiland, J., Wollack, E., & Wright, E. (2007). Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Cosmology. The Astrophysical Journal Supplement, 170(2), 377-408. https://ui.adsabs.harvard.edu/abs/2007ApJS..170..377S/abstract

WMAP 1 Year

Parameters are from Spergel et al. (2003) Table 7 (WMAP + CBI + ACBAR + 2dFGRS + Lya) [WM1]. Tcmb0 and Neff are the standard values as also used for |WMAP5|, |WMAP7|, |WMAP9|.

Note

Pending WMAP team approval and subject to change.

Metadata

Oc0	Omega cold dark matter at z=0
n	Density perturbation spectral index
sigma8	Density perturbation amplitude
tau	Ionisation optical depth
z_reion	Redshift of hydrogen reionisation
t0	Age of the universe in Gyr
reference	Reference for the parameters

References

[WM1]

Spergel, D., Verde, L., Peiris, H., Komatsu, E., Nolta, M., Bennett, C., Halpern, M., Hinshaw, G., Jarosik, N., Kogut, A., Limon, M., Meyer, S., Page, L., Tucker, G., Weiland, J., Wollack, E., & Wright, E. (2003). First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters. The Astrophysical Journal Supplement, 148(1), 175-194. https://ui.adsabs.harvard.edu/abs/2003ApJS..148..175S/abstract

Reference/API

astropy.cosmology.realizations Module

Classes

default_cosmology()

The default cosmology to use.

Variables

available	Built-in immutable sequence.
WMAP1	WMAP1 instance of FlatLambdaCDM cosmology (from Spergel et al. 2003, ApJS, 148, 175, doi: 10.1086/377226.
WMAP3	WMAP3 instance of FlatLambdaCDM cosmology (from Spergel et al. 2007, ApJS, 170, 377, doi: 10.1086/513700.
WMAP5	WMAP5 instance of FlatLambdaCDM cosmology (from Komatsu et al. 2009, ApJS, 180, 330, doi: 10.1088/0067-0049/180/2/330.
WMAP7	WMAP7 instance of FlatLambdaCDM cosmology (from Komatsu et al. 2011, ApJS, 192, 18, doi: 10.1088/0067-0049/192/2/18.
WMAP9	WMAP9 instance of FlatLambdaCDM cosmology (from Hinshaw et al. 2013, ApJS, 208, 19, doi: 10.1088/0067-0049/208/2/19.
Planck13	Planck13 instance of FlatLambdaCDM cosmology (from Planck Collaboration 2014, A&A, 571, A16 (Paper XVI), Table 5 (Planck + WP + highL + BAO))
Planck15	Planck15 instance of FlatLambdaCDM cosmology (from Planck Collaboration 2016, A&A, 594, A13 (Paper XIII), Table 4 (TT, TE, EE + lowP + lensing + ext))
Planck18	Planck18 instance of FlatLambdaCDM cosmology (from Planck Collaboration 2018, 2020, A&A, 641, A6 (Paper VI), Table 2 (TT, TE, EE + lowE + lensing + BAO))

Class Inheritance Diagram