出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The environment plays a key role for the evolution of galaxies residing in galaxy clusters. The detection
of a large-scale, diffuse radio halo around the big elliptical galaxy M86 is reported and its
possible interaction with the Virgo cluster is discussed. A galaxy entering a cluster can have three
kinds of interaction: (i) an interaction with the gravitational potential of the cluster, (ii) an interaction
with another galaxy, (iii) ram pressure stripping due to the galaxy’s rapid motion through
the hot intracluster medium. Since Virgo is the nearest cluster in the northern hemisphere, it represents
an ideal place to investigate these interactions in detail. Spiral galaxies which are evolving
in a cluster environment show decreased gas content and a reduced star formation rate. This is
in general due to a truncation of their gas and star forming disks, whereas the inner disks have
normal gas surface densities and star formation rates with respect to field galaxies of the same
size and Hubble type. We have studied 6 individual Virgo cluster spiral galaxies that experienced
or experience an ISM-ICM interaction, a galaxy-galaxy interaction or a mixture of both. Detailed
comparisons between simulated and observed gas distributions and velocity fields allow us to
identify the kind of interaction that the galaxy underwent and to determine the interaction parameters.
In this way we are beginning to establish a temporal sequence of ram pressure stripping.
We are now at the point where we can start to think about the gas physics of these interactions
(evaporation, phase mixing, change of phase, star formation).
