21-cm hydrogen line and Milky Way spiral structure
Línea de 21 cm del hidrógeno neutro y estructura espiral de la Vía Láctea
- Date
- 1951 · confidence high
- Place
- Harvard University, Cambridge, Massachusetts, United States
- Credited to
- Harold Ewen and Edward Purcell (prediction: Hendrik van de Hulst, 1944)
- People
- 👤 Edward Mills Purcell1912–1997👤 Harold Ewen1922–2015
- Field
- Cosmos & Earth
What was discovered
The detection of radio emission from neutral hydrogen made it possible to map the Galaxy's gas through the dust and revealed its spiral arms for the first time (Oort, Kerr, Westerhout, 1958).
Confirmed weeks later at Kootwijk (Netherlands) and Sydney.
What it led to
- Spiral map of the Milky Way
- Galactic rotation curves
- Cosmology of the reionisation epoch
Built on
Made possible
- Dwingeloo radio telescope