The premature termination of star formation process in some galaxies.
The ultimate quenching of star formation is caused
by stripping of the gas reservoir which will finally turn into stars.
A wide variety of mechanisms have been proposed to provide
quenching. For example, → major mergers
can transform spiral galaxies into ellipticals, and may also
quench future star formation by ejecting the
→ interstellar medium from
the galaxy via starburst, → active galactic nucleus,
or shock-driven winds. In rich clusters,
where merging is less efficient because of
the large relative velocities of galaxies,
rapid encounters or fly-bys may cause the formation of a bar and growth of a
spheroidal component instead of larger scale star formation. Also, cold gas can be
stripped out of the galaxy both by tidal forces
and ram pressure in the intracluster medium. Similarly,
the hot halo that provides future fuel for cooling and star
formation may be efficiently stripped in dense environments, thus quenching
further star formation (see, e.g., Kimm et al., 2009, MNRAS 394, 1131,
arXiv:0810.2794).
See also: → star; → formation;
→ quench.
