Credit: ESA/Hubble & NASA
Acknowledgement: Luca Limatola
Acknowledgement: Luca Limatola
This new Hubble image shows a handful of galaxies in the
constellation of Eridanus (The River). NGC 1190, shown here on the right
of the frame, stands apart from the rest; it belong to an exclusive
club known as Hickson Compact Group 22 (HCG 22).
There are four other members of this group, all of which lie out of
frame: NGC 1189, NGC 1191, NGC 1192, and NGC 1199. The other galaxies
shown here are nearby galaxies 2MASS J03032308-1539079 (centre), and
dCAZ94 HCG 22-21 (left), both of which are not part of HCG 22.
Hickson Compact Groups are incredibly tightly bound groups of
galaxies. Their discoverer Paul Hickson observed only 100 of these
objects, which he described in his HCG catalogue
in the 1980s. To earn the Hickson Compact Group label, there must be at
least four members — each one fairly bright and compact. These
short-lived groups are thought to end their lives as giant elliptical
galaxies, but despite knowing much about their form and destiny, the
role of compact galaxy groups in galactic formation and evolution is
still unclear.
These groups are interesting partly for their self-destructive
tendencies. The group members interact, circling and pulling at one
another until they eventually merge together, signalling the death of
the group, and the birth of a large galaxy.
A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Luca Limatola.
Source: ESA/Hubble - Space Telescope
