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The Balmer Decrement in the Emission Spectra of Astronomical Objects

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The Balmer decrement in the emission spectra of astronomical objects Item Type text; Thesis-Reproduction (electronic) Authors Bloom, Gary Stuart, 1940- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 03/10/2021 20:45:29 Link to Item http://hdl.handle.net/10150/318347 THE BALMER DECREMENT IN THE EMISSION SPECTRA OF ASTRONOMICAL OBJECTS, by Gary Stuart Bloom A Thesis Submitted to the Faculty of the DEPARTMENT OF PHYSICS In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE In the Graduate College THE UNIVERSITY OF ARIZONA 1 9 6 9 STATEMENT BY AUTHOR This thesis has been submitted in partial ful­ fillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowl­ edgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED:__ APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: PREFACE Due to the nature of the problem undertaken, namely, comparison of the Balmer decrements In astronomical emission spectra, the details of this thesis were becoming dated even prior to completion of the work. We have tried to gather together results of all studies pertinent to this report which have been published in English, German, or French prior to the fall of 1 9 6 5. Some studies published in Russian are included, but we do not claim to have exhausted this literature. Work published in other languages have not been included. Due to the necessity of completing this study, we have ignored the promulgation of results currently being published. Inclusion of such data should give more accurate results for some of the objects we examined, and would probably improve the averages which we have computed. At least one such study, Vorontsov-Vel' yaminov et a l , (1965), gives corrections of their former data which we have used in this study. Their recalibration gave them intensity increases upward of 20$. In our search into the literature of objects exhibit­ ing Balmer emission spectra, we inadvertantly overlooked the Wolf-Rayet class of stars which are known to exhibit these ill lines (see5 for example., Ambartsumyan 1958, pp. 490-496). A cursory search to remedy our lack of information about the decrement has not been successful, and we have found only an emission decrement from the nebulosity associated with a WC star. (Andrillat and Andrillat 1953)° TABLE OF CONTENTS PAGE LIST OF TABLES . viii LIST OF ILLUSTRATIONS xvil ABSTRACT » . » o 0 0 0 Q . XX INTRODUCTION . , 1 GENERAL REMARKS 4 The Definition ........... 4 Problems of Measurement . , 4 Corrections to the Raw Data . , 6 The Uses of the Balmer Decrement 10 Types of Intensity Data Found in the Literature . , 11 Normalizing the Data 14 GASEOUS NEBULAE. 15 Historical Remarks 15 The Published Data 17 NGC 1535 .... 20 NGC 1976 . , 22 NGC 2022 .... 22 ■ NGC 2392 .... 27 NGC 2440 . ... ... 28 NGC 6543 . ... 29 NGC 6572 .... 29 NGC 6741 .... 29 NGC 6826 .... 31 NGC 7009 .... 32 NGC 702? .... NGC 7662 .... 1 IC 351....... 36 IC 418 ..... 10 2l49 o 9 a 00 . o © V e e » 38 IC 4997 o6 . a . o 0 *0. » Implications of the :Published Data. 1: Average Decrements for Each Nebula 40 Steep, Average, and Shallow Decrements 45 Summary and Conclusions . 55 v vi TABLE OP CONTENTS--Continued . PAGE STARS f 58 Observational Difficulties and Star Types . 58 Be Stars 61 Variable Stars 62 Pulsating Variablea--.3 Canis Major is Type . , 66 Eruptive Variables-=T Tauri Stars ...... 67 Eruptive Variables--Novae ......... i 67 Description ............... 67 Published Data ............. 71 Eruptive Variables “--Nova-Like Variables . 78 Recurrent Novae ............. 81 R Coronae Borealis Stars ........ 81 P Cygni Stars ...... ....... ... 84 Symbiotic Stars ............. 92 Summary and Evaluation of the Published Data . 106 Additional Data ................. 110 SOLAR PHENOMENA . \ . 112 Solar Regions and the Sites of Hydrogen Emission Spectra ... 112 The Flash Spectrum of the Chromosphere ...... 115 History and Observational Techniques .... 115 Specification of Balmer Decrements in the Chromosphere ............ 122 The Published Data . 128 Normal Regions ............... 128 Excited Regions ............... 133 Discussion of the Data and Some Comparisons ............... 134 The Average Chromospheric • Balmer Decrement ................ 163 Local Phenomena . , . 186 Definitions ..... 186 Presentation of Data and Comments . 189 ' Quiescent Prominences ....... ....... 191 Active Prominences ............. 193 Published Data ............. 193 Analysis of the Data . ........... 196 Limb Flares ................. 200 Dxsk Flares . ■. @ . 201 Summary . ... ® 207 vii TABLE OF COEFEIfPS - -Continued PAGE COMCLTOIMG REMABl^ ................... 210 Galaxies ..................... 210 Quasi-Stellar Objects ............... 212 tE> y . 212 A Suggestion ................... 213 APPMBXX A— Balmer Line Intensity Data as Originally Published for Nebulae ............... 215 APPENDIX B— Balmer Line Intensity Data as Originally Published for Stars ....... ............ 219 APPENDIX C— Balmer Line Intensity Data as Originally Published for the Solar Chromosphere ....... 233 APPENDIX D— Intermediate Steps in the Computer Calculations ................... 251 APPENDIX E— Balmer Line Intensity Data as Originally Published for Solar Flares and Prominences .... 259 BIBLIOGRAPHY ...................... 266 LIST OF TABLES TABLE PAGE 1. Nebulae Examined in Detail with References Thereto ..................... 19 2. Balmer Decrements Published for NGG 1535 ..... 21 3. Averages of Mendez1 11 Point Observations of NGG 1976 23 4. Balmer Decrements Published for NGG 1976 24 5. Balmer Decrements Published for HOC 2022 ..... 27 6. Balmer Decrements Published for NGG 2392 ..... 27 7. Balmer Decrements Published for NGG 2440 ..... 28 8. Balmer Decrements Published for NGG 6543 ..... 29 9. Balmer Decrements Published for NGG 6572*....... 30 10. Balmer Decrements Published for NGG 6741 ..... 31 11. Balmer Decrements Published for NGG 6826 ..... 32 12. Balmer Decrements Published for NGG 7009 ....... 33 i 13. Balmer Decrements Published for NGG 7027 ..... 34 14. Balmer Decrements Published for NGG 7662 ..... 35. 15. Balmer Decrements Published for IC 351 ...... 36 16. Balmer Decrements Published for 10 4l8 ...... 37 17. Balmer Decrements Published for IG 2149 ..... 38 18. Balmer Decrements Published for 10 4997 ..... 39 19. Weights Assigned to Publications in Order to Compute the Average Balmer Decrement for Each Nebula . ......... 44 viii ix LIST OF TABLES— Continued ' TABLE PAGE 20. Weighted Averages of the Balraer Intensities for Selected Nebulae {First Group) ...... 46 21. Weighted Averages of the Balraer Intensities for Selected Nebulae (Second Group) ......... 47 22. Average Balraer Line Decrements for Gaseous Nebulae ......... 50 23. The "Average11 Intensity Range in Gaseous Nebulae for Each Balmer Line and the Number of Nebulae Whose Intensities Fell Within and to Either Side of this Range ...» 52 24. A Comparison of Nebula Balmer-Line Intensities with the Group of "Average".Intensities .... 53 2 5 . Be Stars Examined and References Thereto ..... 61 26. Balmer Line Intensities and Decrements for y Cassiopeiae from 9/37 to 12/38 ........ 63 27. Balmer Decrements of 10 Be Stars ......... 64 28. Balmer Decrement of S Cephei ............ 67 2 9. Balmer Decrements of Two T Taurl Stars ..... .. 6 9. 30. Studies Made of Novae, Published Since. 1950 . , . 72 31. Balmer Decrements of Nova Serp 1909 and Nova ' Scu 1949 ................. 0 . .75 3 2 . Balmer Decrements of Nova Aqu 1918 » . .... 76 33. Balmer Decrements of Nova DK Lae 1950 ...... 77 34. Balmer Decrements of Nova Herculis i960 ..... 78 35. Balmer Decrements of Nova Herculis 1934 ..... 79 3 6. Balmer Decrements of Nova T Coronae Borealis . 82 37. Balmer Decrements of Nova RS Ophluchi 1958 .... 82 3 8 . Balmer Decrements of xx Ophiuchi (HD 116114) . 85 •X LIST OF TABLES--Continued TABLE PAGE 39. Balmer Decrements of P Cyg and HD 51585 ........... 89 40. Balmer Decrements of x Ophiuchl .......... 90 41. Studies Made of Symbiotic Stars Published Since 1950 ......... 93 42. Balmer Decrements of Z Andromedae ......... 97 4 3 . Balmer Decrements of BF Cygni ........... 99 44. Balmer Decrements of WC 6 0 3 ................ 100 4 5 . Balmer Decrements of 01 Cygni ................ 100 46. Balmer Decrements of x C y g n i ......... 101 4 7 . Balmer Decrements of AXPe r s e i .............. 101 48. Balmer Decrements of AG Pegasi .......... 102 4 9 . Balmer Decrements of BDtll°4673 ........... 103 50. Balmer Emission Line Intensity Value Spreads Published for Eight Star. Categories ...... 107 51. Studies of Stars Published Prior to 1950 , . Ill 52. Balmer Line Studies Resulting from Solar Eclipse Observations . ................
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