HST Photometry of Dwarf Elliptical Galaxies in Coma, and an Explanation for the Alleged Structural Dichotomy between Dwarf and Bright Elliptical Galaxies

By Alister W. Graham, R. Guzmán. 2003

378 citations recorded by the source corpus.

As part of a research program exploring how and why dwarf elliptical (dE) galaxies depart from the fundamental plane defined by luminous elliptical (E) galaxies, we have analyzed archival Hubble Space Telescope F606W images of a sample of 18 dE galaxy candidates in the Coma Cluster. We model the full radial extent of their light profiles by simultaneously fitting a point-spread function (PSF) convolved Sérsic R1/n model and, when necessary, either a central point source or a central PSF-convolved Gaussian. Nucleation was detected in all but two of our final sample of 15 dE galaxies. When detected, the luminosities of the central component, Lnuc, scale with the host galaxy luminosity Lgal such that Lnuc = 104.76±0.10(Lgal/107)0.87±0.26. We confirm that the light profiles of the underlying host galaxies display systematic departures from an exponential model that are correlated with the model-independent host galaxy luminosity and are not due to biasing from the nuclear component. The Pearson correlation coefficient between log n and central galaxy surface brightness μ0 (excluding the flux from extraneous central components) is -0.83 at a significance level of 99.99%. Excluding one outlier, the Pearson correlation coefficient between the logarithm of the Sérsic index n and the host galaxy magnitude is -0.77 at a significance of 99.9%. We explain the observed relationship between dE galaxy luminosity and the inner logarithmic profile slope γ′ as a by-product of the correlation between luminosity and Sérsic index n. Including, from the literature, an additional 232 dE and E galaxies spanning 10 mag in absolute magnitude M, the dE galaxies are shown to display a continuous sequence with the brighter E galaxies, such that μ0 brightens linearly with M until core formation causes the most luminous (MB ≲ -20.5) E galaxies to deviate from this relation. The different behavior of dE and E galaxies in the M-⟨μ⟩e (and M-μe) diagram and the ⟨μ⟩e–log Re diagram has nothing to do with core formation and is in fact expected from the continuous and linear relation between M and μ0, and M and log n.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/459b1f973d3ff1dd6a98b12b883b1c01c9604ee8

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

Citations in the corpus

Nuclear star clusters (2009, background): “The NSC luminosity was first compared to the host galaxy/bulge luminosity for small samples of galaxies by Balcells et al. (2003) and Graham and Guzmán (2003).”
The fundamental properties of galaxies and a new galaxy classification system (2006, background): “These objects resemble ellipticals due to their symmetric structure, and elliptical isophotes, although they differ in several significant properties, such as containing different light profiles, and how they follow scaling relations (e.g., Wirth & Gallagher 1984; Graham & Guzman 2003).”
Total Galaxy Magnitudes and Effective Radii from Petrosian Magnitudes and Radii (2005, background): “Indeed, in the case of (dwarf and ordinary) elliptical galaxies, such an approach is crucial if one is to properly understand the various relationships between such terms (e.g., Graham & Guzmán 2003, their Section 4).”
Stellar populations of early-type galaxies in different environments - II. Ages and metallicities (2006, neutral): “2002; Graham & Guzmán 2003).”
The ATLAS3D project – XX. Mass–size and mass–σ distributions of early-type galaxies: bulge fraction drives kinematics, mass-to-light ratio, molecular gas fraction and stellar initial mass function (2012, background): “These models ignore known systematic variations of galaxy morphology with mass (e.g. Caon, Capaccioli & D’Onofrio 1993; Graham & Guzmán 2003; Kormendy et al. 2009; see also Fig.”
THE MBH–LSPHEROID RELATION AT HIGH AND LOW MASSES, THE QUADRATIC GROWTH OF BLACK HOLES, AND INTERMEDIATE-MASS BLACK HOLE CANDIDATES (2012, background): “…coincides with the division between core-Sérsic galaxies (which have a central deficit of light relative to the inward extrapolation of their outer Sérsic light profile) and Sérsic galaxies3 which do not (Graham & Guzmán 2003; Graham et al. 2003; Trujillo et al. 2004; Matković & Guzmán 2005).”
Galaxy And Mass Assembly (GAMA): mass–size relations of z < 0.1 galaxies subdivided by Sérsic index, colour and morphology (2014, methodology): “The curved line is derived from considerations of the Mgal − 〈μ〉e relation (Graham & Guzman 2003) and the luminosity relation, Lgal = 10−Mgal/2.5 = 2 ( πR2e 〈I 〉e ) .”
The ATLAS3D project – III. A census of the stellar angular momentum within the effective radius of early‐type galaxies: unveiling the distribution of fast and slow rotators (2011, background): “…of the Royal Astronomical Society C© 2011 RAS Downloaded from https://academic.oup.com/mnras/article-abstract/414/2/888/976034 by guest on 30 July 2018 (Graham & Guzmán 2003; Graham 2004; Côté et al. 2006; Ferrarese et al. 2006; Kormendy et al. 2009) to examine whether or not different groups…”
Revised Rates of Stellar Disruption in Galactic Nuclei (2003, background): “In spite of their distinct name, dE galaxies have properties that are a smooth continuation to lower luminosities of the properties of brightellipticals (Jerjen & Binggeli 1997, Graham & Guzman 2003).”
SPIDER VIII - constraints on the stellar initial mass function of early-type galaxies from a variety of spectral features (2013, background): “Galaxies are selected to have r-band Petrosian magnitude brighter than −20, corresponding to an absolute Bband magnitude of −19, where the separation between the two families of bright and ordinary ellipticals occurs (Capaccioli, Caon & D’Onofrio 1992; Graham & Guzmán 2003; Trevisan et al. 2012).”
The Coincidence of Nuclear Star Clusters and Active Galactic Nuclei (2008, background): “The luminosity of nuclear star clusters correlates with galaxy luminosity in both ellipticals (Lotz et al. 2001; Graham & Guzmán 2003; Côté et al. 2006) and spirals (Carollo et al. 1998; Böker et al. 2004).”
ANGULAR MOMENTUM AND GALAXY FORMATION REVISITED (2012, methodology): “There is a correlation between M⋆ and n that echos other trends in the literature, and in particular matches the power-law slope of ∼ 0.3 found by Graham & Guzmán (2003).”
Evidence for a New Elliptical-Galaxy Paradigm: Sérsic and Core Galaxies (2004, methodology): “Geha, Guhathakurta, & van der Marel (2002) and Graham & Guzmán (2003) were able to fit the HST profiles of dwarf ellipticals using Sérsic profiles (plus optional nuclear components).”
A Universal Density Profile for Dark and Luminous Matter? (2005, positive): “In a recent series of papers, A. Graham and co-workers have shown that the Sérsic law provides a remarkably good fit to the luminosity profiles of stellar spheroids, from dE galaxies to the most luminous ellipticals (Graham 2001, 2002; Graham & Guzman 2003; Graham et al. 2003; Trujillo et al. 2004).”
THE NUCLEUS OF THE SAGITTARIUS DSPH GALAXY AND M54: A WINDOW ON THE PROCESS OF GALAXY NUCLEATION (2008, background): “Hence, nucleation seems to occur very frequently in both dwarf and giant galaxies (see Graham & Guzmán 2003, and references therein, for a deeper discussion of the dwarf/giant dichotomy).”