Page 21 - 83 basic knowledge of astronomy
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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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