Early galaxies are dominated by bright clumps, which are larger and more massive than in the local Universe. The star formation activity is strongly influenced and can be even halted by a number of processes, some of which are directly related to the environment in which the galaxy resides. Ram pressure stripping, i.e. the removal of interstellar gas from the disk of star forming galaxies due to the hydrodynamical interaction with the hot intergalactic medium, is one such process and it is believed to have a strong impact on galaxy populations in dense environments such as galaxy groups and, especially, clusters.
This Hubble image shows the ram pressure-stripped spiral galaxy IC 3225. Image credit: NASA / ESA / Hubble / M. Sun.
IC 3225 is a spiral galaxy approximately 100 million light-years away in the constellation of Virgo.
Otherwise known as LEDA 40111 or UGC 7441, it was discovered on November 4, 1899 by the German astronomer Arnold Schwassmann.
“IC 3225 looks remarkably as if it’s been launched from a cannon, speeding through space like a comet with a tail of gas streaming from its disk behind it,” the Hubble astronomers said in a statement.
“The galaxy’s location suggests some causes for this active scene, because IC 3225 is one of over 1,300 members of the Virgo galaxy cluster.”
“The density of galaxies in the Virgo cluster creates a rich field of hot gas between them, the so-called intracluster medium, while the cluster’s extreme mass has its galaxies careening around its centre in some very fast orbits.”
“Ramming through the thick intracluster medium, especially close to the cluster’s center, places an enormous ram pressure on the moving galaxies that strips gas out of them as they go.”
“IC 3225 is not so close to the cluster core right now, but astronomers have deduced that it has undergone this ram pressure stripping in the past,” they noted.
“The galaxy looks as though it’s been impacted by this: it is compressed on one side and there has been noticeably more star formation on this leading edge, while the opposite end is stretched out of shape.”
“Being in such a crowded field, a close call with another galaxy could also have tugged on IC 3225 and created this shape.”
“The sight of this distorted galaxy is a reminder of the incredible forces at work on astronomical scales, which can move and reshape even entire galaxies.”
This new image of IC 3225 is made up of observations from Hubble’s Advanced Camera for Surveys (ACS) in the near-infrared and optical parts of the spectrum.
Two filters were used to sample various wavelengths. The color results from assigning different hues to each monochromatic image associated with an individual filter.
Source : Breaking Science News