28-06-2012, 03:17 PM
RADIO ASTRONOMY
[attachment=25964]
Big Advantages of Radio Astronomy
Can observe DAY & NIGHT
Can penetrate clouds
Only stopped by strong winds, thunderstorms and snow!
Radio interferometry can produce better resolution than optical astronomy!
Disadvantages of Radio Astronomy
Powers received are very low, since each photon has a small h
need big collectors (dishes)
Angular resolution is poor: /d
Optical: to get ~0.5 arcsec, =500nm
d~50 cm (but can’t do much better w/o AO or optical interferometry)
Radio: to get ~0.5 arcsec, =5cm
d~50 km
Thus, radio astronomers need interferometers
Radiographs
Colors usually indicate fluxes: red is brightest
Images of supernova remnants
Pulsars and nearby shocks and jets
Black holes: jets in microquasars
Star forming regions
Galactic structure
Radio galaxies
Quasars
[attachment=25964]
Big Advantages of Radio Astronomy
Can observe DAY & NIGHT
Can penetrate clouds
Only stopped by strong winds, thunderstorms and snow!
Radio interferometry can produce better resolution than optical astronomy!
Disadvantages of Radio Astronomy
Powers received are very low, since each photon has a small h
need big collectors (dishes)
Angular resolution is poor: /d
Optical: to get ~0.5 arcsec, =500nm
d~50 cm (but can’t do much better w/o AO or optical interferometry)
Radio: to get ~0.5 arcsec, =5cm
d~50 km
Thus, radio astronomers need interferometers
Radiographs
Colors usually indicate fluxes: red is brightest
Images of supernova remnants
Pulsars and nearby shocks and jets
Black holes: jets in microquasars
Star forming regions
Galactic structure
Radio galaxies
Quasars