The image from the Hubble Space Telescope this week shows a pair of interacting galaxies, which are close enough that they are affecting each other, with the tidal interactions of the two pulling on the tails of the larger galaxy and feeding star formation there. The two galaxies even have a shared name, Arp 298.
“Arp 298 – which comprises the two galaxies NGC 7469 and IC 5283 – lies roughly 200 million light-years from Earth in the constellation Pegasus,” Hubble scientists write. “The larger of the two galaxies pictured here is the barred spiral galaxy NGC 7469, and IC 5283 is its diminutive companion. NGC 7469 is also host to an active, supermassive black hole and a bright ring of star clusters.”
The same pair of galaxies has been observed by Hubble before, in an image released in 2008, though the new image shows the galaxies in great detail. The previous image was taken using Hubble’s Advanced Camera for Surveys (ACS), but the new image combines data from both the ACS and another Hubble instrument, the Wide Field Camera 3. This camera, installed in 2009, adds additional filters to the image to pick out more details over three observations, with a total of seven filters used in the new image as opposed to the three filters used in the previous image.
There will soon be even more detailed images of this galactic pair available, as they will be a target for investigation by the James Webb Space Telescope this summer. Some of Webb’s first science observations will be to investigate the cores of merging galaxies, which are hidden behind a veil of dust in the visible light wavelength. But Webb’s infrared instruments will be able to peer through this dust to learn more about how galaxies merge and how these mergers can trigger star formation.
