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
WMAP 1 Year	Spergel et al. 2003	72.0	0.257	Yes
WMAP 3 Year	Spergel et al. 2007	70.1	0.276	Yes
WMAP 5 Year	Komatsu et al. 2009	70.2	0.277	Yes
WMAP 7 Year	Komatsu et al. 2011	70.4	0.272	Yes
WMAP 9 Year	Hinshaw et al. 2013	69.3	0.287	Yes
Planck 2013	Planck Collab 2013, Paper XVI	67.8	0.307	Yes
Planck 2015	Planck Collab 2015, Paper XIII	67.7	0.307	Yes
Planck 2018	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 WMAP 5 Year, WMAP 7 Year, WMAP 9 Year.

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 WMAP 5 Year, WMAP 7 Year, WMAP 9 Year.

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