共动距离计算器

使用此共动距离计算器快速获得准确的计算结果。

km/s/Mpc

Comoving Distance

428.2857 Mpc

Distance (Mly)1,396.8967 Mly

Comoving Distance vs Redshift (z)

公式

## Comoving Distance Approximation At low redshifts the comoving distance is well approximated by the linear Hubble relation. ### Formula **d = c z / H0** - *c* = 299 800 km/s (speed of light) - *z* = observed redshift - *H0* = Hubble constant The result is in Mpc. For z above about 0.3, higher-order corrections become important.

计算示例

A galaxy at redshift z = 0.1 with H0 = 70 km/s/Mpc.

  1. 01d = c z / H0
  2. 02d = 299800 * 0.1 / 70
  3. 03d = 29980 / 70
  4. 04d ≈ 428.3 Mpc ≈ 1396 Mly

常见问题

What is comoving distance?

It is the distance between two objects measured in a reference frame that expands with the universe. It remains constant as the universe grows.

When does this linear approximation break down?

For redshifts above about 0.3, the non-linear effects of the expansion history (matter and dark energy content) become significant.

How does comoving distance differ from luminosity distance?

Luminosity distance accounts for the dimming of light due to expansion: d_L = d_comoving * (1 + z). It is always larger than the comoving distance.

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