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Astronomy
students beware - two UF researchers have some big changes for
your textbook's section on galaxies.
Using images taken from the Hubble Space Telescope, UF astronomers
Alister Graham and Rafael Guzmán discovered that what were
once believed to be two different kinds of galaxies are actually
structurally identical.
The duo published their findings in this month's edition of The
Astronomical Journal, saying that the commonly found "dwarf
elliptical" galaxies and the much larger "giant elliptical"
galaxies should no longer be categorized differently by the research
community.
"People were convinced that they were unique objects,"
said Graham, who is the lead author of the article. "What
we have now is a model that enables us to connect these two galaxies.
It's quite an interesting revelation."
Galaxies are giant groups of stars scattered through space that
are held together by gravity.
Giant elliptical galaxies can contain more than 100 billion stars,
while dwarf elliptical galaxies typically contain less than one
billion.
While they may differ greatly in size, Graham said they are probably
born in the same way.
"There must be one unifying process which can give birth
to both," Graham said. "The formation process must be
simpler than we thought."
The researchers developed a new mathematical model for the distribution
of stars in order to unite the two galaxy types.
Graham said the difference in size of the two types of galaxies
is likely just a result of the initial size of the gas cloud from
which the given galaxy is believed to have originated.
These large clouds can be several hundred thousand light years
across and are believed to produce the galaxies astronomers now
see.
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