Finally, combining the results of local and high-redshift observations with the prediction of tuned models and simulations, we try to quantify the importance of this process on the evolution of galaxies of different mass, from dwarfs to giants, in various environments and at different epochs.Ībadi MG, Moore B, Bower RG (1999) Ram pressure stripping of spiral galaxies in clusters. We also discuss on the possible fate of the stripped material once removed from the perturbed galaxies and mixed with the ICM, and we try to estimate its contribution to the pollution of the surrounding environment. We summarise the effects of this perturbing process on the baryonic components of galaxies, from the different gas phases (cold atomic and molecular, ionised, hot) to magnetic fields and cosmic rays, and describe their induced effects on the different stellar populations, with a particular attention to its role in the quenching episode generally observed in high-density environments. This review is aimed at describing this physical mechanism in different environments, from rich clusters of galaxies to loose and compact groups. the pressure exerted by the hot and dense intracluster medium (ICM) on galaxies moving at high velocity within the cluster gravitational potential well, is a key process able to remove their interstellar medium (ISM) and quench their activity of star formation.

Among these, ram pressure stripping, i.e.

Astronauts on Servicing Mission 4 in May 2009 were able to restore ACS during their 13-day mission.Galaxies living in rich environments are suffering different perturbations able to drastically affect their evolution. Studying ram pressure stripping helps astronomers better understand the mechanisms that drive the evolution of galaxies, and how the rate of star formation is suppressed in very dense regions of the universe such as clusters.īoth images were taken by the Advanced Camera for Surveys on Hubble before it suffered from a power failure in 2007. This interaction can result in peculiar-looking galaxies. As it moves through this intra-cluster medium, strong winds rip through it, sweeping out gas and dust, distorting its shape, and even halting star formation. Ram pressure stripping happens when a galaxy moves through the intra-cluster medium. For galaxies, it happens as they orbit around the center of the cluster, moving through the intra-cluster medium. It’s much like the wind you feel in your face when bicycling, even on a still day. The process at work in these galaxies ram pressure stripping is the drag force that results when something moves through a fluid. Light shining from the galaxy’s disc backlights the swirling dust that is being swept out by the gas. It’s thought this appearance is a result of the forces exerted by the intra-cluster medium, which is an extremely hot X-ray emitting gas found between galaxies within galactic clusters. One sign is the curved, or convex, appearance of the galaxy’s disc. The image also shows distant background galaxies.Īnother galaxy, NGC 4402 – shown at right – also displays some telltale signs of being stripped of its gas and dust. Bright blue pockets of new star formation can be seen to the right and left of center. It highlights the dramatic state of the galaxy, with an especially vivid view of the ghostly gas being forced out of it.

A number of star clusters that formed in the stripped gas can be seen in the Hubble image.Įven though this is a still image, Hubble’s view of NGC 4522 practically swirls off the page with apparent movement. Scientists estimate that NGC 4522 is moving at more than 10 million kilometers per hour. The galaxy’s rapid motion within the Virgo cluster results in strong winds across the galaxy as the gas within is left behind. It is a spectacular example of a spiral galaxy currently being stripped of its gas content. It is located in the Virgo cluster some 60 million light-years away from Earth. The spiral galaxy NGC 4522 – shown at the top of this post – is one of the galaxies. Two galaxies in the Virgo Cluster show themselves affected by ram pressure stripping in a set of Hubble Space Telescope images.

Ram pressure striping