Suppose you saw an object in the sky that you suspected might be a
quasar.  What sort of observations might you perform to find out if
indeed it was a quasar?

Hi ceowang,

What a fascinating question. I was able to locate some great
information on this topic for you.

From "Frequently Asked Questions about Quasars" which can be found at
the following URL:
http://campus.pc.edu/faculty/rarts/courses/physics/105/notes/Topic_9_Galaxies/Quasar.htm

"When radio telescopes were first turned on the heavens, point sources
of radio waves were discovered (along with spread-out regions of
emission along our Milky Way). Astronomers using ordinary
visible-light telescopes turned toward these radio points and looked
to see what was there. In some cases a supernova remnant was found, in
others, a large star-birth region, in others a distant galaxy. But in
some places where point sources of radio waves were found, no visible
source other than a stellar-looking object was found (it looked like a
point of light --- like a star does). These objects were called the
"qausi-stellar radio sources", or "quasars" for short."

Also, from "quasar, Definition from AP Dictionary of Science and
Technology" which can be found at:
http://www.academicpress.com/inscight/06081998/quasars4.htm

"a compact quasi-stellar radio source or visible object; characterized
by spectra with high redshifts, implying great distances and
consequent high rates of energy production; thought to be the most
distant and most luminous objects in the universe. (From quasi-stellar
radio source, the first type of quasar discovered.) a compact
quasi-stellar radio source or visible object; characterized by spectra
with high redshifts, implying great distances and consequent high
rates of energy production; thought to be the most distant and most
luminous objects in the universe. (From quasi-stellar radio source,
the first type of quasar discovered.)"

Essentially, what you would need to do to confirm that an object
observed is a quasar would be to observe the radio waves from the
object and confirm that the spectra has a high redshift.

Thanks for your great question!

Legolas-ga


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