Light Eye
01-11-2005, 11:15 AM
dear friends,
another mystery ;-)
http://ucsdnews.ucsd.edu/newsrel/science/mcquasar.asp
be well, be love.
david
january 10, 2005
discovery by ucsd astronomers poses a cosmic puzzle:
can a 'distant' quasar lie within a nearby galaxy?
by kim mcdonald
an international team of astronomers has discovered within the heart of a nearby
spiral galaxy a quasar whose light spectrum indicates that it is billions of
light years away. the finding poses a cosmic puzzle: how could a galaxy 300
million light years away contain a stellar object several billion light years
away?
the team?s findings, which were presented today in san diego at the january
meeting of the american astronomical society and which will appear in the
february 10 issue of the astrophysical journal, raise a fundamental problem for
astronomers who had long assumed that the ?high redshifts? in the light spectra
of quasars meant these objects were among the fastest receding objects in the
universe and, therefore, billions of light years away.
?most people have wanted to argue that quasars are right at the edge of the
universe,? said geoffrey burbidge, a professor of physics and astronomer at the
university of california at san diego?s center for astrophysics and space
sciences and a member of the team. ?but too many of them are being found closely
associated with nearby, active galaxies for this to be accidental. if this
quasar is physically associated with this galaxy, it must be close by.?
astronomers generally estimate the distances to stellar objects by the speed
with which they are receding from the earth. that recession velocity is
calculated by measuring the amount the star?s light spectra is shifted to the
lower frequency, or red end, of the light spectrum. this physical phenomenon,
known as the doppler effect, can be experienced by someone standing near train
tracks when the whistle or engine sounds from a moving train becomes lower in
pitch, or sound frequency, as the train travels past.
[non-text portions of this message have been removed]
another mystery ;-)
http://ucsdnews.ucsd.edu/newsrel/science/mcquasar.asp
be well, be love.
david
january 10, 2005
discovery by ucsd astronomers poses a cosmic puzzle:
can a 'distant' quasar lie within a nearby galaxy?
by kim mcdonald
an international team of astronomers has discovered within the heart of a nearby
spiral galaxy a quasar whose light spectrum indicates that it is billions of
light years away. the finding poses a cosmic puzzle: how could a galaxy 300
million light years away contain a stellar object several billion light years
away?
the team?s findings, which were presented today in san diego at the january
meeting of the american astronomical society and which will appear in the
february 10 issue of the astrophysical journal, raise a fundamental problem for
astronomers who had long assumed that the ?high redshifts? in the light spectra
of quasars meant these objects were among the fastest receding objects in the
universe and, therefore, billions of light years away.
?most people have wanted to argue that quasars are right at the edge of the
universe,? said geoffrey burbidge, a professor of physics and astronomer at the
university of california at san diego?s center for astrophysics and space
sciences and a member of the team. ?but too many of them are being found closely
associated with nearby, active galaxies for this to be accidental. if this
quasar is physically associated with this galaxy, it must be close by.?
astronomers generally estimate the distances to stellar objects by the speed
with which they are receding from the earth. that recession velocity is
calculated by measuring the amount the star?s light spectra is shifted to the
lower frequency, or red end, of the light spectrum. this physical phenomenon,
known as the doppler effect, can be experienced by someone standing near train
tracks when the whistle or engine sounds from a moving train becomes lower in
pitch, or sound frequency, as the train travels past.
[non-text portions of this message have been removed]