This artist's concept illustrates one possible answer to the puzzle of
the "giant galactic blobs." These blobs (red), first identified about
five years ago, are mammoth clouds of intensely glowing material that
surround distant galaxies (white). Astronomers using visible-light
telescopes can see the glow of the blobs, but they didn't know what
provides the energy to light them up. NASA's Spitzer Space Telescope set
its infrared eyes on one well-known blob located 11 billion light-years
away, and discovered three tremendously bright galaxies, each shining
with the light of more than one trillion Suns, headed toward each other.
Spitzer also observed three other blobs in the same galactic neighborhood
and found equally bright galaxies within them. One of these blobs is also
known to contain galaxies merging together. The findings suggest that
galactic mergers might be the mysterious source of blobs.
If so, then one explanation for how mergers produce such large clouds of
material is that they trigger intense bursts of star formation. This star
formation would lead to exploding massive stars, or supernovae, which
would then shoot gases outward in a phenomenon known as superwinds. Blobs
produced in this fashion are illustrated in this artist's concept.
