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Title: Differential spectral synthesis with a library of elliptical galaxies

Abstract

Spectrophotometry of elliptical galaxies spanning a large rang in luminosity is analyzed for cosmic variations in color and line strength. The results are used to construct a base sequence spectral energy distribution as a function line strength, color, and velocity dispersion, representing old, red, uniform elliptical galaxy stellar populations. The sequence can be used as the starting point for investigating and modeling the stellar populations of other systems such as dwarf ellipticals, merger remnants, and, eventually, high redshift ellipticals.

Authors:
Publication Date:
Research Org.:
Lawrence Livermore National Lab., CA (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
205931
Report Number(s):
UCRL-JC-122895; CONF-9510317-1
ON: DE96007662; TRN: 96:008682
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Conference
Resource Relation:
Conference: From stars to galaxies: the impact of stellar physics on galaxy evolution, Porto Elounda Mare (Greece), 9-13 Oct 1995; Other Information: PBD: 7 Dec 1995
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; GALAXIES; CLASSIFICATION; ENERGY SPECTRA; SPECTRAL DENSITY

Citation Formats

Gregg, M. Differential spectral synthesis with a library of elliptical galaxies. United States: N. p., 1995. Web.
Gregg, M. Differential spectral synthesis with a library of elliptical galaxies. United States.
Gregg, M. Thu . "Differential spectral synthesis with a library of elliptical galaxies". United States. doi:. https://www.osti.gov/servlets/purl/205931.
@article{osti_205931,
title = {Differential spectral synthesis with a library of elliptical galaxies},
author = {Gregg, M.},
abstractNote = {Spectrophotometry of elliptical galaxies spanning a large rang in luminosity is analyzed for cosmic variations in color and line strength. The results are used to construct a base sequence spectral energy distribution as a function line strength, color, and velocity dispersion, representing old, red, uniform elliptical galaxy stellar populations. The sequence can be used as the starting point for investigating and modeling the stellar populations of other systems such as dwarf ellipticals, merger remnants, and, eventually, high redshift ellipticals.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Dec 07 00:00:00 EST 1995},
month = {Thu Dec 07 00:00:00 EST 1995}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

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  • This study makes use of a technique of differential spectral synthesis which compares the spectrum of a spiral bulge to a fiducial sequence based on similar spectra of elliptical galaxies. This approach allows differences to be interpreted in terms of age since the elliptical sequence derives from a stellar population of uniform age in which metallicity varies. The spectrophotometry for this project was obtained with the IIDS spectrometer on the 2.1 m telescope at KPNO. Broad-band photometry was also gathered at KPNO and is used to study the color-luminosity and color-color relations. The results of this comparative study are summarized.
  • The possibility that the far-UV flux in elliptical galaxies originates from post-asymptotic giant branch stars is examined in the frame of the theory of stellar evolution. It has been found that in an old stellar generation the mass of stars in this phase is an increasing function of the metal content and a decreasing one of the helium content. Model spectral energy distributions computed with the method of the evolutionary synthesis, taking into account all the evolutionary phases in a self-consistent way, show that both the required UV flux and the observed correlation between the metallicity and the (1550-V) colormore » can be reproduced. The UV and visible spectra of M32 and some giant elliptical galaxies are compared with model spectral distributions of single generations and galaxies. Evidence is presented in the case of M32 that different models, corresponding to different birthrates can be fitted to the observed continuum. 42 references.« less
  • New results on surface photometry and kinematics findings on elliptical galaxies are presented. Isophote shapes, color gradients, minor axis rotations, and kinematically distinct cores are reported. The implications of the findings for the intrinsic shapes of the ellipticals are addressed. 47 refs.
  • I review recent research on the evolution of elliptical galaxies in high redshift galaxy clusters. Significant progress is being made on many fronts using the powerful tools of e.g. HST and 10 m class telescopes. But determining the actual age of composite stellar populations in distant galaxies is still beyond our capabilities.