Astrophysics (Index)About

peculiar velocity

(peculiar motion)
(velocity with respect to local rest)

Peculiar velocity is the motion of an object with respect to local rest. "Rest" depends upon observation and purpose. For a star within a galaxy, "rest" might be taken as the mean motion of nearby stars, i.e., how this star's movement differs from the general motion of those around it. For distant galaxies, e.g., in cosmology studies, "rest" might be taken as the motion respect to the Hubble flow, i.e., the expected motion away from us due to Hubble's law.

Further reading:

Referenced by pages:
Alcock-Paczyński effect (AP effect)
baryon acoustic oscillations (BAO)
CMB anisotropies
galactic archaeology
Hubble expansion
Local Group (LG)
Local Sheet
moving-cluster method
radial velocity (RV)
redshift (z)
redshift space
solar apex
stellar association
stellar kinematics
systemic velocity
Sunyaev-Zel'dovich effect (SZ effect)
velocity-metallicity relation