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Download What is Radio Astronomy - MIT Haystack Observatory
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What is Radio Astronomy? MIT Haystack Observatory This material was developed under a grant from the National Science Foundation The Electromagnetic Spectrum • Spans a range of wavelengths • Visible is just a narrow range • Radiowaves span a large range - from under 1mm to several meters Sources of Radio emission • Solar System - sun, planets • Milky way - star forming regions, old stars, supernova remnants • Extragalactic - quasars, radio jets • Molecules Sun OPTICAL RADIO XRAY Saturn RADIO INFRARED OPTICAL ULTRAVIOLET Orion Nebula: Stars are born… RADIO INFRARED OPTICAL XRAY Crab Nebula: a star that died in 1054 RADIO OPTICAL XRAY Cassiopeia A: a star that died in ~1700 RADIO INFRARED OPTICAL XRAY Sagittarius A: Mystery Mass in Galaxy Center RADIO OPTICAL Virgo A: Hidden Massive Black Hole shooting out a Jet RADIO OPTICAL Molecules What are molecules good for? • Detections - newest one - “glycoaldehyde” (sugar) • Probes - measure temperature, density, chemistry • Kinematics - velocities - doppler effect HC3N as a density probe in the Taurus Molecular Cloud (TMC-1) CH3CCH as a temperature probe in TMC-1 Model of H2O maser emission around NGC4258 How do radio telescopes work? What is Resolution? Interferometry Getting better “resolution” NRAO/AUI Compare the radio image on the right, made with the Haystack 37-m single dish telescope at a frequency of 43 GHz with the radio image above made with the 27element Very Large Array. VLBI images of SiO maser emission in Orion and a possible model SiO Masers around a highly evolved star - R Cassiopeia VLBI sequence of a supernova in M81 Magnetic Fields in Active Galactic Nuclei • The Blazar 1055+018 – Active Galactic Nuclei – 15 billion light years distant – AGN are 40 times more luminous and 10,000 times larger than the brightest “normal” galaxies – Displays a colossal jet of relativistic plasma – Powered by a supermassive, rotating black hole
