Page 21 - 83 basic knowledge of astronomy

Wavelength λ (m)
10 4 10 2 1 10 −2 10 −4 10 −6 10 −8 10 −10 10 −12 10 −14
10 15

10 10

10 5
Intensity I ν (W Hz −1 m −2 rad −2 ) 10 −5
1

−10
10

10 −15

10 −20
8
9
10
7
3
2
4
6
5
T=1K 10K 10 K 10 K 10 K 10 K10 K10 K 10 K10 K10 K
10 −25
10 4 10 6 10 8 10 10 10 12 10 14 10 16 10 18 10 20 10 22
Frequency ν (Hz)
Figure 20: Planck spectrum of black body radiation. Each curve corresponds
to a certain absolute thermodynamic temperature value.

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