Hubble snaps picture of another jellyfish galaxy

Another jellyfish galaxy
Click for original image.

Astronomers today released another picture of a jellyfish galaxy taken by the Hubble Space Telescope, with that picture to the right, cropped, reduced, and sharpened to post here. From the caption:

The jellyfish galaxy JO206 trails across this image from the NASA/ESA Hubble Space Telescope, showcasing a colourful star-forming disc surrounded by a pale, luminous cloud of dust. A handful of bright stars with criss-cross diffraction spikes stand out against an inky black backdrop at the bottom of the image. JO206 lies over 700 million light-years from Earth in the constellation Aquarius.

This image is the sixth and final such photograph in this survey. You can view all of these images here. The study has found that star formation does not seem to be significantly different inside the galaxy versus the tentacles that stretch out beyond due to pressure from the intergalactic material. This suggests that the influence of this intergalactic material on the formation of stars is relatively minor.

Jellyfish galaxy plowing its way through the intercluster medium

Jellyfish galaxy plowing through the intercluster medium
Click for original image.

The European Space Agency (ESA) today released another in a series of images taken by the Hubble Space Telescope during the past two years of what astronomers call jellyfish galaxies, so named because such galaxies have tendrils that extend out beyond the galaxy like the tendrils of jellyfish. This new picture is to the right, cropped, reduced, and sharpened to post here, and shows a galaxy about 900 million light years away.

[T]he space between galaxies in a cluster is … pervaded with a searingly hot plasma known as the intracluster medium. While this plasma is extremely tenuous, galaxies moving through it experience it almost like swimmers fighting against a current, and this interaction can strip galaxies of their star-forming gas. This interaction between the intracluster medium and the galaxies is called ram-pressure stripping, and is the process responsible for the trailing tendrils of this jellyfish galaxy.

The arrow in the image indicates the galaxy’s direction of travel through the intercluster medium, resulting in the outer parts of the leading arm to be pushed backward above the galaxy, while material at its rear trail behind. Note also the blue star-forming regions at the galaxy’s bow. The ram pressure is also apparently causing more star formation in this part of the galaxy compared to elsewhere.