Mapping the galactic gravitational potential with peculiar acceleration

Understand

It has been suggested recently that the change in cosmological redshift (the Sandage test of expansion) could be observed in the next generation of large telescopes and ultra-stable spectrographs.

• In a recent paper we estimated the change of peculiar velocity, i.e.
• the peculiar acceleration, in nearby galaxies and clusters and shown it to be of the same order of magnitude as the typical cosmological signal.
• Mapping the acceleration field allows for a reconstruction of the galactic gravitational potential without assuming virialization.