Arp 148
88.
Arp 148 is the staggering aftermath of an encounter between two galaxies, resulting in a ringshaped galaxy and a long-tailed companion. The collision between the two parent galaxies
produced a shockwave effect that first drew matter into the centre and then caused it to
propagate outwards in a ring. The elongated companion perpendicular to the ring suggests
that Arp 148 is a unique snapshot of an ongoing collision. Infrared observations reveal a strong
obscuration region that appears as a dark dust lane across the nucleus in optical light.
This image is part of a large collection of 59 images of merging galaxies taken by the Hubble
Space Telescope and released on the occasion of its 18th anniversary on 24th April 2008.
Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A.
Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), K. Noll (STScI),
and J. Westphal (Caltech)
Stellar
89. fireworks
ablaze in NGC 4449
Hundreds of thousands of vibrant blue and red stars are visible in this
image of galaxy NGC 4449. Hot bluish white clusters of massive stars
are scattered throughout the galaxy, interspersed with numerous
dustier reddish regions of current star formation. Massive dark clouds
of gas and dust are silhouetted against the flaming starlight.
Credit: NASA, ESA, A. Aloisi (STScI/ESA), and The Hubble Heritage
(STScI/AURA)-ESA/Hubble Collaboration