Andrew Yee[_1_]
April 20th 07, 03:21 PM
News Service
Iowa State University
Contacts:
Frank Krennrich, Physics and Astronomy
(515) 294-3736
Martin Pohl, Physics and Astronomy
(515) 294-6448
Mike Krapfl, News Service
(515) 294-4917
4-19-07
Iowa State astrophysicists provide the eyes for new gamma ray telescope
system
AMES, Iowa -- There's a "First Light Fiesta" in the works at Mt. Hopkins
near Amado, Ariz. And Iowa State University astrophysicists will be among
those enjoying the celebration of a new telescope system and all the science
it will produce.
The $20 million VERITAS telescope system -- that's the Very Energetic
Radiation Imaging Telescope Array System -- at the Fred Lawrence Whipple
Observatory south of Tucson doesn't look like the telescope you used in high
school. It's made of four reflectors 12 meters across that look like
satellite dishes. The reflectors are covered with mirrors that direct light
into cameras attached to the front of each dish. Each camera is about 7 feet
across and contains 500 tube-shaped photon detectors or pixels. The
telescope system is based on techniques Iowa State researchers Richard Lamb
and David Carter-Lewis helped develop in the 1980s.
All those detectors for the VERITAS system were built in a laboratory on the
fourth floor of Iowa State's Zaffarano Physics Addition. It took about $1
million and a lot of work by Iowa State post-doctoral researchers Tomoyuki
Nagai and Martin Schroedter to do it.
Frank Krennrich, an Iowa State professor of physics and astronomy and leader
of Iowa State's work on the VERITAS project, said the telescope system will
be looking for gamma rays from space.
VERITAS is the northern hemisphere's most sensitive instrument for finding
that high energy electromagnetic radiation. And gamma rays do have lots of
energy: the energy of visible light is one electron volt; gamma rays have
energies of one million to one trillion electron volts.
Even with all that energy, the rays can't penetrate the earth's atmosphere.
But when they hit the atmosphere they create showers of electrons and
positrons that create a blue light known as Cerenkov radiation. The showers
move very fast. And they're not very bright.
So it takes a powerful instrument to find them. The astronomers say VERITAS
is proving to be as sensitive as they expected.
"The quality of the data is so much better," Krennrich said. "The more
telescopes you have, the higher the resolution for these measurements."
That's good news to Martin Pohl, an Iowa State assistant professor of
physics and astronomy who's working to analyze and explain the data from the
VERITAS observations, and Asif Imran, an Iowa State doctoral student whose
dissertation includes the analysis of VERITAS data.
"Being able to see more precisely allows you to ask more precise questions,"
Pohl said.
Astrophysicists now know that gamma rays are produced by supermassive black
holes, supernova remnants, pulsars, gamma ray bursts and other space
objects. The crab Nebula is one source of gamma rays.
Researchers believe more knowledge of gamma rays could help them explore
distant regions of space, help them look for evidence of dark matter,
determine how much electromagnetic radiation the universe has produced,
answer questions about the formation of stars and help explain the origins
of the most energetic radiation in the universe.
Without the improvements in data now being produced by VERITAS, "You're like
a fish on the beach," Pohl said.
And so these Iowa State astrophysicists have good reason to celebrate the
telescope system's first light April 27-29 in the Arizona mountains.
"This is a pretty big deal," Krennrich said. "We have worked 10 years on
this."
[NOTE: Images supporting this release are available at
http://www.iastate.edu/~nscentral/news/2007/apr/veritas.shtml ]
Iowa State University
Contacts:
Frank Krennrich, Physics and Astronomy
(515) 294-3736
Martin Pohl, Physics and Astronomy
(515) 294-6448
Mike Krapfl, News Service
(515) 294-4917
4-19-07
Iowa State astrophysicists provide the eyes for new gamma ray telescope
system
AMES, Iowa -- There's a "First Light Fiesta" in the works at Mt. Hopkins
near Amado, Ariz. And Iowa State University astrophysicists will be among
those enjoying the celebration of a new telescope system and all the science
it will produce.
The $20 million VERITAS telescope system -- that's the Very Energetic
Radiation Imaging Telescope Array System -- at the Fred Lawrence Whipple
Observatory south of Tucson doesn't look like the telescope you used in high
school. It's made of four reflectors 12 meters across that look like
satellite dishes. The reflectors are covered with mirrors that direct light
into cameras attached to the front of each dish. Each camera is about 7 feet
across and contains 500 tube-shaped photon detectors or pixels. The
telescope system is based on techniques Iowa State researchers Richard Lamb
and David Carter-Lewis helped develop in the 1980s.
All those detectors for the VERITAS system were built in a laboratory on the
fourth floor of Iowa State's Zaffarano Physics Addition. It took about $1
million and a lot of work by Iowa State post-doctoral researchers Tomoyuki
Nagai and Martin Schroedter to do it.
Frank Krennrich, an Iowa State professor of physics and astronomy and leader
of Iowa State's work on the VERITAS project, said the telescope system will
be looking for gamma rays from space.
VERITAS is the northern hemisphere's most sensitive instrument for finding
that high energy electromagnetic radiation. And gamma rays do have lots of
energy: the energy of visible light is one electron volt; gamma rays have
energies of one million to one trillion electron volts.
Even with all that energy, the rays can't penetrate the earth's atmosphere.
But when they hit the atmosphere they create showers of electrons and
positrons that create a blue light known as Cerenkov radiation. The showers
move very fast. And they're not very bright.
So it takes a powerful instrument to find them. The astronomers say VERITAS
is proving to be as sensitive as they expected.
"The quality of the data is so much better," Krennrich said. "The more
telescopes you have, the higher the resolution for these measurements."
That's good news to Martin Pohl, an Iowa State assistant professor of
physics and astronomy who's working to analyze and explain the data from the
VERITAS observations, and Asif Imran, an Iowa State doctoral student whose
dissertation includes the analysis of VERITAS data.
"Being able to see more precisely allows you to ask more precise questions,"
Pohl said.
Astrophysicists now know that gamma rays are produced by supermassive black
holes, supernova remnants, pulsars, gamma ray bursts and other space
objects. The crab Nebula is one source of gamma rays.
Researchers believe more knowledge of gamma rays could help them explore
distant regions of space, help them look for evidence of dark matter,
determine how much electromagnetic radiation the universe has produced,
answer questions about the formation of stars and help explain the origins
of the most energetic radiation in the universe.
Without the improvements in data now being produced by VERITAS, "You're like
a fish on the beach," Pohl said.
And so these Iowa State astrophysicists have good reason to celebrate the
telescope system's first light April 27-29 in the Arizona mountains.
"This is a pretty big deal," Krennrich said. "We have worked 10 years on
this."
[NOTE: Images supporting this release are available at
http://www.iastate.edu/~nscentral/news/2007/apr/veritas.shtml ]