Transcript Radio Astronomy: An Informal Talk

Radio Astronomy:
An Informal Talk
Presented to the
Society of Physics Students
Northern Virginia Community College
19 November
by
Prof. Harold Geller, GMU
What I’ll talk about
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Telescopes
Electromagnetic waves
Radioastronomy basics
NRAO at Green Bank, West Virginia
Small Radio Telescope at George Mason
University
What does a telescope do?
• Collect electromagnetic waves
– Collecting ability proportional to the square of
the diameter of the objective
• Resolve electromagnetic sources
– Related to the atmosphere, wavelength and
curvature of the objective
• Magnify surfaces of planets and the Moon
– Magnification only of Moon, Sun and planets
Looking
Beyond the
Eyes
Optical Telescopes
Reflector
Refractor
Different Views of Sun
Sun in Hydrogen-alpha
Sun in X-ray
Radio
Astronomy
Basics
A Little More Detail
Jansky’s Original Radiotelescope
Grote Reber’s Telescope
170 foot
Diameter
Radiotelescope at
Green Bank,
WV
The 100meter Green
Bank
Telescope
Even Bigger than you Think
Jupiter in
Radio
Saturn in Radio
3C296
Radio/Optical
Composite
A Vision for George Mason
(based upon Univ. Indianapolis)
Small Radio Telescope
Justification
• Radio science observations in the L-band
– L-band lies in the 1400-1427 MHz region of
the electromagnetic spectrum
– detection of what astronomers call the 21-cm
line of hydrogen
• this is a portion of the hydrogen spectrum, in the
radio region of the electromagnetic spectrum, which
is generated by the neutral hydrogen clouds in the
interstellar medium
Small Radio Telescope
Justification
• Observations in C-band, which is 43134338 MHz and 3788-3813 MHz
– Radio science observations in the C-band allow
for the radio emission examination of the
moon, which acts as a body at a temperature of
200 K.
– Students will be able to scan the moon, and
detect the estimated 6000 joules of energy from
the lunar surface.
GMU SRT Background
• Funding
– National Science Foundation
• education portion of grant won by Dr. Rita Sambruna
• Order History
– ordered first week of June 2002
• stated 12 week delivery time
– received 15 October 2002
• damaged antenna
GMU SRT Background Part II
• Order History
– boxes damaged
– FedEx insurance inspector called and visited to
assess damage - refused claim
– replacement parts to be shipped by vendor
• Base assembled on roof
– 1 November 2002
• Remaining electronics and replacement
antenna parts received 30 January 2003
Did You Say Fragile?
Picking Up the Pieces on the Roof
Whistle While You Work
Tolerance
Cleanup On The Roof
The Base Of SRT
Servo Motors Attachment
Servos with Ring Assembly
Dish/Receiver Assembly
Readying for Final Mechanical
Assembly
From Mechanical to Electrical
Assembled and Ready to Test
Sample Data
Even Smaller - Radio Jove
Small Radio Science
Demonstration Projects
• Undergraduate research
– Steve Richardson
• web site built with some results from data acquired
using U of Indianapolis
– http://physics.gmu.edu/~arichar6/radio/index.html
• prepared presentation for GMU “innovations” fair
• prepared presentation for CPAC meeting at Bucknell
University
Really Smoothing
Playing With The Data
A Potpourri Of Color
Family Portrait (2001 conference)
Radio Astronomy Observatory at
George Mason University
Looking
To The
Future
Future GMU Observatory
OnLine References
• http://www.aoc.nrao.edu/intro/image.index.html
• http://www.aoc.nrao.edu/intro/faq.html
• http://donald.phast.umass.edu/~fcrao/education/re
port1.html
• http://www.haystack.mit.edu/
• http://www.jpl.nasa.gov/radioastronomy/
• http://www.bambi.net/sara.html
• http://radiojove.gsfc.nasa.gov/
Book References
• Radio Astronomy by John D. Kraus
• An Introduction to Radio Astronomy by Bernard
Burke
• The Amateur Radio Astronomer’s Handbook by
John Potter Shields
• Radio Astronomy for the Amateur by David
Heiserman
• Radio Astronomy (Above and Beyond) by Adele
Richardson
Many Thanks
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Rita Sambruna (GMU)
Maria Dworzecka (GMU)
Justin Brown (GMU)
Dan Thomas (GMU)
Kathy Santiago (NVCC)
John Avellone
Christopher Helm
National Science Foundation (NSF)
MIT Haystack Observatory