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  • Getting Started
  • User Guide
  • Development
  • Project details
  • Tutorials
  • GitHub

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Data structures and transformations

  • Constants (astropy.constants)
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Files, I/O, and Communication

  • Unified File Read/Write Interface
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  • SAMP (Simple Application Messaging Protocol) (astropy.samp)

Computations and utilities

  • Cosmological Calculations (astropy.cosmology)
    • Included Cosmology Realizations
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  • Convolution and Filtering (astropy.convolution)
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  • Data Visualization (astropy.visualization)
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Nuts and bolts

  • Configuration System (astropy.config)
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  • Logging system
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  • Astropy Core Package Utilities (astropy.utils)
  • Astropy Glossary
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  • Cosmological Units and Equivalencies
  • with_H0

with_H0#

astropy.cosmology.units.with_H0(H0=None)[source]#

Convert between quantities with little-h and the equivalent physical units.

Parameters:
H0None or Quantity [:ref: ‘frequency’]

The value of the Hubble constant to assume. If a Quantity, will assume the quantity is H0. If None (default), use the H0 attribute from default_cosmology.

References

For an illuminating discussion on why you may or may not want to use little-h at all, see https://arxiv.org/pdf/1308.4150.pdf

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