scholarly journals Stellar Populations in Dwarf Elliptical Galaxies

1996 ◽  
Vol 171 ◽  
pp. 382-382 ◽  
Author(s):  
J. Gorgas ◽  
S. Pedraz ◽  
N. Cardiel ◽  
J.J. Gonzalez
Keyword(s):  
Stellar Population ◽  
Line Strength ◽  
Stellar Populations ◽  
Elliptical Galaxies ◽  
Population Models ◽  
Wide Range ◽  
Central Regions ◽  
Single Burst ◽  
Dwarf Elliptical Galaxies ◽  
Measured Line

We present the results of a spectroscopic study in which we have measured line-strength indices in a sample of 5 dwarf and 2 compact elliptical galaxies (mostly from Virgo). Some conclusions about the stellar populations in dwarf E's are derived by comparing the sample with classical E galaxies. In the adjacent figure, we plot in the Hβ-[MgFe] plane the central indices of our sample of dwarf and compact E's together with data from González (1993, PhD Thesis). The grid represents the predictions of single-burst stellar population models from Worthey (1994, ApJS, 95, 107). The main conclusion is that, whilst the central regions of giant, intermediate and compact ellipticals span, according to stellar population models, a wide range in mean stellar ages, bright dwarf ellipticals are found to be old, compatible with a ∼ 10 Gyr old stellar population. This means that the dichotomy found in the Fundamental Plane between dwarf ellipticals and the gE-iE-cE sequence (Bender, Burstein & Faber 1992, ApJ, 399, 462) is also observed in the stellar populations.

scholarly journals 3D view on Virgo and field dwarf elliptical galaxies: late-type origin and environmental transformations

2012 ◽  
Vol 10 (H16) ◽  
pp. 334-334
Author(s):  
Agnieszka Ryś ◽  
Jesús Falcón-Barroso ◽  
Glenn van de Ven
Keyword(s):  
Large Scale ◽  
Stellar Population ◽  
Line Strength ◽  
Elliptical Galaxies ◽  
Formation Mechanisms ◽  
Population Parameters ◽  
Irregular Galaxies ◽  
Model Predictions ◽  
Dwarf Elliptical Galaxies ◽  
Star Formation Histories

AbstractIn our contribution we show the effects of environmental evolution on cluster and field dwarf elliptical galaxies (dEs), presenting the first large-scale integral-field spectroscopic data for this galaxy class. Our sample con sists of 12 galaxies and no two of them are alike. We find that the level of rotation is not tied to flattening; we observe kinematic twists; we discover large-scale kinematically-decoupled components; we see varying gradient s in line-strength maps: from nearly flat to strongly peaked in the center. The great variety of morphological, kinematic, and stellar population parameters seen in our data supports the claim that dEs are defunct dwarf spiral/irregular galaxies and points to a formation scenario that allows for a stochastic shaping of galaxy properties. The combined influence of ram-pressure stripping and harassment fulfills these requirements, still, the exact impact of the two is not yet understood. We further investigate the properties of our sample by performing a detailed comprehensive analysis of its kinematic, dynamical, and stellar population parameters. The combined knowledge of the dynamical properties and star-formation histories, together with model predictions for different formation mechanisms, will be used to quant itatively determine the actual transformation paths for these galaxies.

scholarly journals A first glance into the Spectral Energy Distributions of Single Stellar Populations in the Infrared range

2011 ◽  
Vol 7 (S284) ◽  
pp. 32-34 ◽  
Author(s):  
Sofia Meneses-Goytia ◽  
Reynier F. Peletier
Keyword(s):  
Stellar Population ◽  
Stellar Populations ◽  
Elliptical Galaxies ◽  
Population Models ◽  
Spectral Energy ◽  
Infrared Range ◽  
Optical Range ◽  
Spectral Energy Distributions ◽  
Energy Distributions ◽  
K Band

AbstractThe present work shows the Spectral Energy Distributions (SEDs) in the infrared using the IRTF stellar library, obtained using models based on Single Stellar population Models (SSP). We have focused on the K band in order to compare with observables of elliptical galaxies. We also present the comparisons of our models with velocity dispersions, ages and metallicities obtained with models in the optical range.

scholarly journals Physical Properties of Nearby Dwarf Elliptical Galaxies

2006 ◽  
Vol 2 (S235) ◽  
pp. 69-69
Author(s):  
M. R. Seo ◽  
H. B. Ann
Keyword(s):  
Physical Properties ◽  
Stellar Populations ◽  
Elliptical Galaxies ◽  
High Density ◽  
Emission Lines ◽  
Dwarf Elliptical Galaxies ◽  
Nuclear Regions

AbstractMost dwarf elliptical galaxies except for ‘dE, N’ galaxies which are characterized by young stellar populations in the nuclear regions are located in the high density environment. The colors and spectra of ‘dE, N’ galaxies are different from other types, in the sense that they have redder colors with little emission lines. The majority of dwarf elliptical galaxies are younger than 7 Gyr with metallicity larger than [z/H]=−0.5.

scholarly journals Kinematics of Nuclei of Sc Galaxies

1980 ◽  
Vol 5 ◽  
pp. 191-191
Author(s):  
V. C. Rubin
Keyword(s):  
High Velocity ◽  
Stellar Population ◽  
Hii Regions ◽  
Emission Lines ◽  
High Luminosity ◽  
Rotation Curves ◽  
Velocity Gradients ◽  
Wide Range ◽  
Central Regions ◽  
Velocity Dispersions

For a sample of 21 Sc galaxies with a wide range of luminosities, of radii, and of masses, W. K. Ford and I have obtained spectra and determined rotation curves. By their kinematical behavior in their central regions, the Sc’s can be separated into two groups. Some galaxies, generally small and of low luminosity, have shallow central velocity gradients, reflecting their low central masses and densities. Other galaxies, most often large ones of high luminosity, have steep central velocity gradients. One reason this separation by central velocity gradients is of interest is because these galaxies exhibit other significant spectral differences which go hand-in-hand with the kinematical differences.The small, low luminosity galaxies show emission lines of Hα and [NII], with nuclear Ha sharp and stronger than [NII], and little or no stellar nuclear continuum, just as conventional HII regions. In contrast, the high luminosity galaxies show broad nuclear emission, with [NII] stronger than Ha. These galaxies have a strong red stellar continuum, arising from a red stellar population. The cause of the Hα[NII] intensity reversal in the nuclei of some galaxies remains unknown. However, the strong [NII] emission in generally high luminosity galaxies with massive nuclei, nuclei which show strong red continua, suggests that [Nil] intensity correlates with nuclear luminosity, and in turn with the density and velocity properties of the nuclear populations. We would expect high velocity dispersions and high bulge luminosities for galaxies with strong nuclear [NII] and steep central velocity gradients.

Stellar Populations in Dwarf Elliptical Galaxies

1996 ◽  
pp. 382-382
Author(s):  
J. Gorgas ◽  
S. Pedraz ◽  
N. Cardiel ◽  
J. J. Gonzalez
Keyword(s):  
Stellar Populations ◽  
Elliptical Galaxies ◽  
Dwarf Elliptical Galaxies

Stellar populations in local group dwarf elliptical galaxies. I - NGC 147

1983 ◽  
Vol 270 ◽  
pp. 471 ◽  
Author(s):  
J. R. Mould ◽  
J. Kristian ◽  
G. S. Da Costa
Keyword(s):  
Local Group ◽  
Stellar Populations ◽  
Elliptical Galaxies ◽  
Dwarf Elliptical Galaxies

scholarly journals The relation between stellar populations, structure and environment for dwarf elliptical galaxies from the MAGPOP-ITP

2008 ◽  
Vol 385 (3) ◽  
pp. 1374-1392 ◽  
Author(s):  
D. Michielsen ◽  
A. Boselli ◽  
C. J. Conselice ◽  
E. Toloba ◽  
I. M. Whiley ◽  
...  
Keyword(s):  
Stellar Populations ◽  
Elliptical Galaxies ◽  
Dwarf Elliptical Galaxies

scholarly journals Stellar population synthesis: Application To Galactic Bulges

1993 ◽  
Vol 153 ◽  
pp. 133-150
Author(s):  
N. Arimoto
Keyword(s):  
Observational Data ◽  
Stellar Population ◽  
Stellar Populations ◽  
Population Synthesis ◽  
Firm Conclusion ◽  
Formation History ◽  
Stellar Population Synthesis ◽  
Central Regions ◽  
History Of ◽  
Metallicity Distribution

The stellar populations give traces of the formation history of the bulges. The metallicity distribution of K-giants in the Galactic bulge resembles to that of the giant ellipticals. There seems to be no conspicuous colour-magnitude relation intrinsic to the bulges. This can be explained if the bulges formed by the dissipative collapse of central regions of proto-galaxies followed by the supernova-driven bulge wind which was induced later than the dwarf ellipticals of the similar mass (the biased wind). Unfortunately, the observational data available at present of stellar populations of the bulges are not yet sufficient to get a firm conclusion on the origin of the bulges.

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