1	Radio Astronomy Ganesh Sankaranarayanan Graduate Student Electrical Engineering
2	UW Campus Observatory Built in 1892 Located on 4^th and University St Moved in 1895 to the current location Second Building on campus next to denny hall
3	Telescope 6-inch Brashear objective lens Warner & Swasey equatorial mount 90-inch focal length Warner & Swasey wooden , rests on 3 civil war era cannon balls!
4	Visible World
5	Electromagnetic spectrum Electromagnetic radiation The visible world (We see very little!) Radio spectrum X-ray, UV,IR spectrum
6	History of Radio Astronomy Serendipity?
7	History of Radio Astronomy
8	Radio Sources 21-cm Neutral Hydrogen Lines
9	Radio Sources 21-cm Neutral Hydrogen lines Discovery Emission once in few million years 80% Hydrogen in Universe 21-cm emission not obstructed by dust Used to map galaxies and ISM
10	Milky Way in 21cm
11	M33 Radio and Optical Composite
12	Orion Nebula M42
13	Radio Sources Pulsars Discovered in 1967 Rapidly rotating neutron star 10-15 km radius Cosmic clocks in the sky First thought to be a signal from aliens (“little green men”)
14	Sounds of Pulsars
15	Pulsar and Supernova Remnant
16	Crab Nebula Pulsar
17	Radio Sources Quasars Quasar : Quasi- stellar radio source Most distant object to emit radio waves Contain super massive black holes in the center Radio emission produced by synchrotron radiation Reflect the stage of universe billions of years ago
18	Quasar
19	Radio Sources MASERS Dense molecular clouds with strong emission (T > 10⁶ K) MASER action Microwave Amplification by Stimulated Emission of Radiation OH,H₂O,SiO, CH₃CH₂OH and more…
20	Water MASER
21	Radio Sources Cosmic Microwave Background Radiation
22	Cosmic Microwave Background Radiation
23	Radio Sources Sun
24	Radio Sources Planets
25	Radio Telescopes Arecibo Located in Puerto Rico Operated by Cornell and NSF 1000 ft (304.8 m) Used for Astronomy, atmospheric and planetary studies
26	Radio Telescopes Green Bank Telescope Located in Green bank, West Virginia 485 feet tall -- taller than the Statue of Liberty! 100 by 110 m width World’s Largest steerable radio telescope
27	Radio Telescopes VLI (Very Large Array) Located in Socorro, NM 27 antennas interferometer Each antenna 25 meters( 82 feet) in diameter
28	VLBI (Very Large Baseline Array)
29	ALMA The Atacama Large Millimeter Array Atacama desert, Chile 64 radio telescopes 12 meter (39 feet) wide dish antenna Expected to operate in 2011
30	Radio Telescopes around the world Europe Westerbork Synthesis Radio Telescope (WSRT) , Netherlands The Ryle Telescope, United Kingdom Australia Mopra Observatory Asia Giant Meterwave Radio Telescope(GMRT) , India Nobeyama millimeter array ,Japan
31	Radio Astronomy at UW UAI established in 1999 7ft dish Currently building motion control and receivers for 21cm hydrogen lines (1420 MHz)
32	Future of Radio Astronomy More cost to build radio telescopes Consortium among countries to build future telescopes Major advancements in telescope technologies Better design to control noise over effective area GMRT,ALMA Better angular resolution Encroachment of radio frequencies by ground and satellite communications More power in deciding frequency allocations Better modulation techniques to prevent spill over
33	The End