NGC 2623:
Merging Galaxies from Hubble
From
NASA’s Astronomy Picture of the Day
Where
do stars form when galaxies collide?
To
help find out, astronomers imaged the nearby galaxy merger NGC 2623 in
high resolution with the Hubble
Space Telescope.
Analysis
of this and other Hubble images as well as images of NGC
2623 in infrared
light by the Spitzer Space
Telescope, in X-ray
light by XMM-Newton,
and in ultraviolet
light by GALEX,
indicate that two originally spiral galaxies appear
now to be greatly convolved and that their cores have unified into one active galactic
nucleus (AGN).
Star
formation continues around this core near the featured image center,
along the stretched out tidal
tails visible on either side, and perhaps surprisingly, in an off-nuclear
region on the upper left where clusters of
bright blue stars appear.
Galaxy collisions can
take hundreds of millions of years and take several gravitationally destructive
passes.
NGC 2623, also known
as Arp 243, spans
about 50,000 light years and lies about 250 million light years away toward the
constellation of the Crab (Cancer).
Reconstructing the
original galaxies and how galaxy mergers happen
is often challenging, sometimes impossible, but generally important to
understanding how our
universe evolved.
