Page 3 - analysis-and-interpretation-of-astronomical-sp

Analysis and Interpretation of Astronomical Spectra 3

8 Calibration, Normalisation and Radiometric Correction ...................................27

8.1 The Calibration of the Wavelength .............................................................................................. 27
8.2
8.3 The Selective Attenuation of the Continuum Intensity .............................................................. 27
8.4
8.5 Relationship Between Original-Continuum and Pseudo-Continuum ...................... 28
8.6
8.7 Attenuation of Absorption Lines .................................................................................................. 28
8.8
8.9 Attenuation of the Emission Lines ............................................................................................... 29
8.10
8.11 Summary of the consequences: ................................................................................................... 30
8.12
8.13 The Importance of the Pseudo-Continuum ................................................................................. 30
8.14
8.15 Proportional Radiometric Corrections of the Pseudo-Continuum............................................. 30

Rectification of the Continuum Intensity..................................................................................... 31

Relative Radiometric Flux Calibration by a Synthetic Continuum ............................................. 32

Relative Radiometric Profile Correction by Recorded Standard Stars...................................... 35

Absolute Flux Calibration.............................................................................................................. 37

Intensity Comparison between Different Spectral Lines ........................................................... 37

Reconstruction of the Original Emission-Line Intensities.......................................................... 37

Summary – Which Method Fits to Which Task........................................................................... 38

9 Visible Effects of Quantum Mechanics ...............................................................39

9.1 Textbook Example Hydrogen Atom and Balmer Series .............................................................. 39
9.2 The Balmer Series ......................................................................................................................... 40
9.3 Spectral Lines of Other Atoms ..................................................................................................... 41

10 Wavelength and Energy .......................................................................................42

10.1 Planck’s Energy Equation.............................................................................................................. 42
10.2 Units for Energy and Wavelength ................................................................................................ 42
10.3 The Photon Energy of the Balmer Series..................................................................................... 43
10.4 Balmer- Paschen- and Bracket Continuum ................................................................................. 44

11 Ionisation Stage and Degree of Ionisation .........................................................45

11.1 The Lyman Limit of Hydrogen....................................................................................................... 45
11.2 Ionisation Stage versus Degree of Ionisation ............................................................................. 45
11.3 Astrophysical Form of Notation for the Ionisation Stage ........................................................... 45

12 Forbidden Lines or –Transitions..........................................................................46

13 The Spectral Classes ............................................................................................47

13.1 Preliminary Remarks ..................................................................................................................... 47
13.2 The Fraunhofer Lines .................................................................................................................... 47
13.3 Further Development Steps.......................................................................................................... 48
13.4 The Harvard System ...................................................................................................................... 49
13.5 “Early” and “Late” Spectral Types ................................................................................................ 50
13.6 The MK (Morgan Keenan) or Yerkes System .............................................................................. 50
13.7 Further Adaptations up to the Present ........................................................................................ 50
13.8 The Rough Estimation of the Spectral Class ............................................................................... 52
13.9 Diagrams for Estimation of the Spectral Class ........................................................................... 53
13.10 Additional Criteria for Estimation of the Spectral Class............................................................. 54
13.11 Appearance of Elements, Ions and Molecules in the Spectra ................................................... 55
13.12 Effect of the Luminosity Class on the Line Width ....................................................................... 56
13.13 Spectral Class and B-V Colour-Index ........................................................................................... 56

14 The Hertzsprung - Russell Diagram (HRD) .........................................................57

14.1 Introduction to the Basic Version................................................................................................. 57
14.2 The Absolute Magnitude and Photospheric Temperature of the Star ...................................... 58