Astronomy Picture of the Day – 16 Jul 06 “The center of our Galaxy is a busy place. In visible light, much of the Galactic Center is obscured by opaque dust. In infrared light, however, dust glows more and obscures less, allowing nearly one million stars to be recorded in the above photograph. The Galactic Center itself appears on the right and is located about 30,000 light years away towards the constellation of Sagittarius. The Galactic Plane of our Milky Way Galaxy, the plane in which the Sun orbits, is identifiable by the dark diagonal dust lane. The absorbing dust grains are created in the atmospheres of cool red-giant stars and grow in molecular clouds. The region directly surrounding the Galactic Center glows brightly in radio and high-energy radiation, and is thought to house a large black hole.” [taken from http://antwrp.gsfc.nasa.gov/apod/ap060716.html]

REU Summer 2006: KSU SRT Project Ashley K. Wheeler Mentor: Dr. Tim Bolton

Outline Why radio astronomy? How are radio waves emitted? What is radio astronomy? Versus optical astronomy? How are radio waves emitted? Basic Schematic Resolution Summary, pre-REU

Outline, cont. REU Software Sweeps/ Waveforms Aliasing Data Comparison What is it? Why is it a problem? Data Comparison Baselines and Averaging Possible Sources

Outline, cont. What’s next? Software Mounting For More Information

Why radio astronomy? What is radio astronomy? Versus optical astronomy? [figure borrowed from http://www.disp.duke.edu/~dbrady/ece371/notes/l2/spectrum.html]

How are radio waves emitted? Black bodies Ionized gas clouds Change in energy states and masers Electron plus magnetic field (non-thermal) Moving magnetic field (non-thermal)

Basic Schematic

Resolution q = 1.03l/D = 1.03(c/n)/D 0.02575 radians, or about 1.5 degrees

Summary, pre-REU Sat finders and tees

REU CNVTWFM Moved the dish outside 1st sweep – Jun 20th, 2006

REU, cont.

REU, cont. Aliasing

REU, cont. Data comparison

REU, cont. Baselines and averaging

REU, cont. Manhattan, KS 39.179642 -> dec. of +39o 10’ 46.7112” Name/ Type RA Dec. S 5 GHz (Jy) 4C 39.23/ Quasar 08:24:55.483 865 +39 16 41.90430 0.99 ?/ Quasar 10:23:11.565 623 +39 48 15.385 39 0.87 NGC 1023/ Galaxy 02:40:48.5 +39 05 27 Manhattan, KS 39.179642 -> dec. of +39o 10’ 46.7112” RA = (our time of day) + (5 hrs)

Next, cont. Signal processing software Mounting?

For More Information The Astronomical Almanac www.radio.uindy.edu www.nrao.edu/epo/amateur www.wikipedia.org www.bambi.net