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Study of the stellar populations in galaxies from integrated spectra (Record no. 14472)

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fixed length control field 03910nam a2200229Ia 4500
003 - CONTROL NUMBER IDENTIFIER
control field IN-BaIIA
005 - DATE AND TIME OF LATEST TRANSACTION
control field 20211110143352.0
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 043:523.983
Item number PAT
100 ## - MAIN ENTRY--PERSONAL NAME
Personal name Pati, A. K
9 (RLIN) 25713
Relator term Author
245 #0 - TITLE STATEMENT
Title Study of the stellar populations in galaxies from integrated spectra
Remainder of title a thesis submitted for the degree of Doctor of Philosophy in the faculty of science, Bangalore University, Bangalore
Statement of responsibility, etc. A. K. Pati
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. 1988
500 ## - GENERAL NOTE
General note Thesis Supervisors J. C. Bhattacharyya and K. S. Raghavendra Rao
502 ## - DISSERTATION NOTE
Degree type Doctor of Philosophy
Name of granting institution Indian Institute of Astrophysics, Bangalore
Year degree granted 1988
520 ## - SUMMARY, ETC.
Summary, etc. In the foregoing chapters we have detailed a study of the populations of stars in early type galaxies. The method used for the study is that of population synthesis, in which the observed spectrum of a galaxy is matched by the co-added spectra of stars of known types within the Galaxy. <br/> We have obtained spectroscopic data of galaxies and stars belonging to standard stellar types and carried out reduction of the data to finally obtain the energy distribution as a function of wavelength. The library of stellar spectra for use in population synthesis has to cover the entire range of stars seen and studied within the galaxy. The compilation of such a library, with each stellar group observed a suffi- cient number of times to get good representative averages, can take a lot of observing time. Since such compilations have been made earlier, it is prudent to use them, if possible. We have used an existing library after augmenting it with our own stellar observations. <br/>Three early type galaxies were studied in this work; of these, NGC 4472 in the Virgo cluster has been the subject of many earlier investigations, including the derivation of its stellar content using population synthesis The second galaxy is a typical early type galaxy, in the sense that it was not known to show any signs of activity characterized by emission lines in the spectrum, abnormal colors or morphology or radio emission. These has hardly been any earlier work on this galaxy, except for measurements of radial velocities and photometry. The third galaxy, NGC 5128, also known as Centaurus A, is in that class of elliptical galaxies classified as peculiar. It is one of the most powerful sources of radiowave radiation in the sky and had other features such as the gigantic band of dust and gas obsuring part of the light, which have attempt at attracted much attention; strangely no population synthesis using optical spectra have been made before. <br/>For the galaxy NGC 4472, we find evidence for star formation activity in the region observed (which was the optically bright centre of the galaxy) to the extent thought possible by others, from studies of strengths of spectral lines (Rose 1985). We also find that the last major star formation activity in the galaxy occurred 8 to 10 giga years ago as indicated by the main sequence turnoff point derived. One puzzling result that we get in the best constrained synthesis model is that contrary to what is believed of giant elliptical galaxies, NGC 4472 does not have a significant proportion of metal rich giant stars. We feel that the stellar libraries used in population synthesis should discriminate between different metallicities among dwarf stars, particularly of late spectral type, to resolve this problem. Very cool metal rich giant stars such as now known to exist at the centre of our Galaxy, should also be used in the stellar library.
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical term or geographic name entry element Galaxies
9 (RLIN) 1286
650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical term or geographic name entry element Steallar Populations
9 (RLIN) 25714
700 ## - ADDED ENTRY--PERSONAL NAME
Personal name J. C. Bhattacharyya and K. S. Raghavendra Rao
Fuller form of name Supervisor
9 (RLIN) 48868
856 ## - ELECTRONIC LOCATION AND ACCESS
Uniform Resource Identifier <a href="http://prints.iiap.res.in/handle/2248/109">http://prints.iiap.res.in/handle/2248/109</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
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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
    Universal Decimal Classification     IIA Library-Bangalore IIA Library-Bangalore General Stacks 13/02/2002 043:523.983/ PAT 15394 05/11/2021 13/02/2002 Thesis & Dissertations

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