# Atomspheres of the components of close binary stars (Record no. 14174)

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000 -LEADER | |
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fixed length control field | 05767nam a2200241Ia 4500 |

003 - CONTROL NUMBER IDENTIFIER | |

control field | IN-BaIIA |

005 - DATE AND TIME OF LATEST TRANSACTION | |

control field | 20211110141441.0 |

008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION | |

fixed length control field | 211028s9999 xx 000 0 eng d |

040 ## - CATALOGING SOURCE | |

Transcribing agency | IIA Library |

080 ## - UNIVERSAL DECIMAL CLASSIFICATION NUMBER | |

Universal Decimal Classification number | (043)524.38 |

100 ## - MAIN ENTRY--PERSONAL NAME | |

Personal name | Rao, M. S |

9 (RLIN) | 24950 |

Relator term | Author |

245 #0 - TITLE STATEMENT | |

Title | Atomspheres of the components of close binary stars |

Remainder of title | a thesis submitted to for the degree of doctor of philosophy in the faculty of Science, Bangalore University, Bangalore |

Statement of responsibility, etc. | M. S. Rao |

Medium | [Ph.D Thesis] |

260 ## - PUBLICATION, DISTRIBUTION, ETC. | |

Place of publication, distribution, etc. | Bangalore |

Name of publisher, distributor, etc. | Indian Institute of Astrophysics |

Date of publication, distribution, etc. | 2001 |

300 ## - PHYSICAL DESCRIPTION | |

Extent | x, 178p. |

500 ## - GENERAL NOTE | |

General note | Thesis Supervisor Prof. A. Peraiah |

502 ## - DISSERTATION NOTE | |

Degree type | Doctor of Philosophy |

Name of granting institution | Indian Institute of Astrophysics, Bangalore |

Year degree granted | 2001 |

520 ## - SUMMARY, ETC. | |

Summary, etc. | For theoretical modeling of binary systems one has to consider realistic<br/>models which takes into account the radiative transfer, hydrodynamics.<br/>reflection effect etc. Since the problem is complex, we study in the thesis<br/>some of idealized models which will help us in understanding the important<br/>physical processes in close binaries. Intially we have computed the<br/>theoretical lines in the expanding and extended distorted atmospheres of<br/>the components of close binary system. I have considered the necessary<br/>geometrical formalism for illumination of a stellar atmospheres from a<br/>source. We describe the method to calculate the radiation field from the<br/>irradiated surface of the component in a binary system.<br/>Chapter 1<br/>Discrete Space theory of Radiative transfer: In this chapter a<br/>concise description of the lnethod of obtaining the solution of radiative<br/>transfer equation which can be applied to different geometrical and physical<br/>systellls is given. This method was developed by Grant and Peraiah<br/>(1972), and Peraiah and Grant(1973). This chapter deals with (1) interaction<br/>principle (2) star product (3) calculation of radiation field at<br/>internal points (4) integration of monochromatic radiative transfer equation<br/>and derivation of rand t operators of the" cell". (5) flux conservation<br/>and (6) line formation in expanding media.<br/>The radiative transfer equation in spherical symmetry is used for calculating<br/>the self radiation of the primary star in a binary system.<br/>Chapter 2<br/>Reflection effect in close binaries : The aim of this section is to<br/>estimate the radiation field along the spherical surface of a primary component<br/>irradiated by an external point source of radiation. This can be<br/>applied to very widely separated systems. The transfer of radiation incident<br/>on the atmosphere of the component from the companion cannot be<br/>studied by using any symmetric solution of the equation of transfer. This<br/>needs a special treatment. We adopt angle-free one dimensional model<br/>(see Sobolev 1963).<br/>Chapter 3<br/>Incident radiation from an extended source: The effects of irradiation<br/>from an extended source of the secondary cOInponent on the<br/>atmospheres of the primary are studied.<br/>Chapter 4<br/>(1) Effects of reflection on spectral line forlllation: Effects of<br/>reflection on formation of spectral lines in a purely scattering atmosphere<br/>and studied how the equivalent widths change when irradiation from the<br/>secondary is taken into account. However, these calculations were done<br/>in static atnlospheres. So in the next step we have included the expanding<br/>atmospheres.<br/>(2) Effects of irradiation on the line formation in the expanding<br/>atmospheres of the components of a close binary system : We<br/>studied the formation of lines in the irradiated expanding atmospheres<br/>of the component of close binary system. We considered two-level atom<br/>approximation in non-LTE situation with complete l'<.'clistribution. We<br/>assumed that the dust scatters isotropically in the atmosphere. The line<br/>profiles of the dusty atmosphere are compared with those formed in dust<br/>free atmosphere. The profiles are presented for different velocities of<br/>expansion, proximity of secondary component to the primary, and dust<br/>optical depths.<br/>The line profiles for a dust free atmosphere with and without reflection<br/>effects are computed and compared.<br/>Chapter 5<br/>Distorted surface due to self rotation and tidal forces: In this<br/>chapter a general expression for gravity darkening of the tidally uniformly<br/>rotating roche components of close binary system is derived. This theory<br/>is used to calculate the line profiles taking into account rotation and<br/>expansion velocities.<br/>Chnpter 6<br/>Effect of gravity darkening on spectral line forlnation : We studied<br/>the transfer of line radiation in the atmospheres of close binary components<br/>whose atmospheres are distorted by the self radiation and tidal<br/>forces due to the presence of the secondary component. The distortion<br/>is measured in terms of the ratio of angular velocities at the equator and<br/>pole, mass ratio of the two components, the ratio of centrifugal force to<br/>that of gravity at the equator and the ratio of the equatorial radius to the<br/>distance between the centers of gravity. We obtain the equation of the<br/>distorted surface by solving a seventh degree equation which contains the<br/>above parameters. Transfer of line radiation is studied in such asymmetric<br/>atmosphere assuming complete redistribution and a two-level atom<br/>approximation. The atmosphere is assumed to be expanding radially.<br/>Various black body temperatures are being used to describe the total<br/>luminosity of the components for the purpose of irradiation.<br/>Chapter 7<br/>Conclusions: We present important results obtained from this study<br/>of research from each chapter. |

650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |

Topical term or geographic name entry element | binary stars |

9 (RLIN) | 1185 |

650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |

Topical term or geographic name entry element | thesis |

9 (RLIN) | 18401 |

700 ## - ADDED ENTRY--PERSONAL NAME | |

Personal name | A. Peraiah |

Relator term | Supervisor |

9 (RLIN) | 48850 |

856 ## - ELECTRONIC LOCATION AND ACCESS | |

Uniform Resource Identifier | <a href="http://prints.iiap.res.in/handle/2248/112">http://prints.iiap.res.in/handle/2248/112</a> |

Link text | Click Here to Access eThesis |

942 ## - ADDED ENTRY ELEMENTS (KOHA) | |

Koha item type | Thesis & Dissertations |

Source of classification or shelving scheme | Universal Decimal Classification |

Withdrawn status | Lost status | Source of classification or shelving scheme | Damaged status | Not for loan | Home library | Current library | Shelving location | Date acquired | Full call number | Barcode | Date last seen | Price effective from | Koha item type |
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Universal Decimal Classification | IIA Library-Bangalore | IIA Library-Bangalore | General Stacks | 20/07/2001 | (043)524.38 | 15094 | 05/11/2021 | 20/07/2001 | Thesis & Dissertations |