Evidence for a New Elliptical-Galaxy Paradigm: Sérsic and Core Galaxies

By Ignacio Trujillo, P. Erwin, A. Ramos, Alister W. Graham. 2004

174 citations recorded by the source corpus.

We fitted the surface-brightness profiles of 21 elliptical galaxies using both the Sérsic function and a new empirical model that combines an inner power law with an outer Sérsic function. The profiles are combinations of deconvolved Hubble Space Telescope (HST) profiles from the literature and ellipse fits to the full WFPC2 mosaic images and thus span a radial range from ∼0.″02 to about twice the half-light radius. We are able to accurately fit the entire profiles using either the Sérsic function or our new model. In doing so, we demonstrate that most, if not all, so-called "power-law" galaxies are better described as "Sérsic galaxies"—they are well modeled by the three-parameter Sérsic profile into the limits of HST resolution—and that "core" galaxies are best understood as consisting of an outer Sérsic profile with an inner power-law cusp, which is a downward deviation from the inward extrapolation of the Sérsic profile. This definition of cores resolves ambiguities that result when the popular "Nuker law" is fitted to the profiles of ellipticals and bulges, particularly at lower luminosities. We also find that using the Nuker law to model core-galaxy nuclear profiles systematically overestimates the core radii by factors of 1.5–4.5 and underestimates the inner power-law slope by ∼20%–40% or more.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/6f6ed2756dfd471fba7cd392f625e87b8b7f9baf

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Citations in the corpus

How do minor mergers promote inside-out growth of ellipticals, transforming the size, density profile and dark matter fraction? (2012, methodology): “…- provides a powerful explanation for the predominance of high Sersic indices of present day large and massive ellipticals (Graham et al. 2001; Trujillo et al. 2004; Kormendy et al. 2009; Hoyos 2011; Kormendy & Bender 2012) some of which are most likely the descendants of compact ’red and…”
A Universal Density Profile for Dark and Luminous Matter? (2005, unknown): “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).”
Structure and Kinematics of Early-Type Galaxies from Integral Field Spectroscopy (2016, methodology): “The amount of σ variation is again in principle sufficient to explain a major part of the FP tilt (Ciotti et al. 1996; Graham & Colless 1997; Prugniel & Simien 1997; Bertin et al. 2002; Trujillo et al. 2004a).”
A Fundamental Relation between Compact Stellar Nuclei, Supermassive Black Holes, and Their Host Galaxies (2006, methodology): “1; Ferrarese et al. 2006; Trujillo et al. 2004).”
STRUCTURE AND FORMATION OF ELLIPTICAL AND SPHEROIDAL GALAXIES (2008, background): “The dichotomy has been challenged by Jerjen & Binggeli (1997); Graham & Guzmán (2003); Graham et al. (2003); Trujillo et al. (2004), and Gavazzi et al. (2005).”
Resolved Galaxies in the Hubble Ultra Deep Field: Star Formation in Disks at High Redshift (2007, background): “…Conselice et al. 2004 and references therein; Pasquali et al. 2006), the Sérsic index for the surface brightness profile (Sérsic 1968; see, e.g., Trujillo et al. 2004; Ravindranath et al. 2006), the rest-frame spectral energy distribution (SED; Benı́tez 2000; Coe et al. 2006), and the Gini…”
The DART Imaging And CaT Survey of the Fornax Dwarf Spheroidal Galaxy (2006, background): “…projected light distribution of elliptical galaxies and the bulges of spiral galaxies (e.g. Caon et al. 1993; Caldwell 1999; Graham & Guzmán 2003; Trujillo et al. 2004): IS(R) = I0,S exp − ( R RS )1/m (2) where I0,S is the central surface density,RS is a scale radius andm is the…”
A Concise Reference to (Projected) Sérsic R 1/n Quantities, Including Concentration, Profile Slopes, Petrosian Indices, and Kron Magnitudes (2005, methodology): “Although the reader is referred to the above papers, especially the Appendix of Trujillo et al. (2004), the core–Sérsic model is given as7: I(R) = I ′ [ 1 + ( Rb R )α]γ/α exp { −b[(Rα + Rαb )/R α e ] 1/(αn) } , (33) 6The luminous ‘core galaxies’ likely correspond to the ‘bright’ family of galaxies…”
THE SINFONI BLACK HOLE SURVEY: THE BLACK HOLE FUNDAMENTAL PLANE REVISITED AND THE PATHS OF (CO)EVOLUTION OF SUPERMASSIVE BLACK HOLES AND BULGES (2016, unknown): “Our result agrees with Trujillo et al. (2004).”
The SAURON project – IX. A kinematic classification for early‐type galaxies (2007, methodology): “Results from fitting Sersic and Sersic-core laws (Trujillo et al. 2004; Ferrarese et al. 2006) to the radial luminosity profiles will be presented in detail in a subsequent paper of this series (FalcónBarroso et al., in prep.).”
THE MBH–LSPHEROID RELATION AT HIGH AND LOW MASSES, THE QUADRATIC GROWTH OF BLACK HOLES, AND INTERMEDIATE-MASS BLACK HOLE CANDIDATES (2012, methodology): “…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).”
Fundamental Planes and the Barless MBH-σ Relation for Supermassive Black Holes (2008, background): “M32 may be a stripped S0 galaxy (Bekki et al. 2001; Graham 2002), while NGC 2778 is a disk galaxy (Rix, Carollo & Freeman 1999) as is NGC 4564 (Trujillo et al. 2004; see also figure 6 in Graham & Driver 2007a).”
SIZES AND SURFACE BRIGHTNESS PROFILES OF QUIESCENT GALAXIES AT z ∼ 2 (2011, methodology): “Sérsic (1968) profiles are commonly used, since these have been shown to closely match the surface brightness profiles of nearby early-type galax- ies (e.g., Caon et al. 1993; Graham et al. 2003; Trujillo et al. 2004; Ferrarese et al. 2006; Côté et al. 2007; Kormendy et al. 2009).”
Rates of stellar tidal disruption as probes of the supermassive black hole mass function (2014, methodology): “Moreover, 21 galaxies in this sample overlap with the tabulated Sersic and core-Sersic parameters given in Trujillo et al. (2004), allowing us to perform a detailed comparison between the TDE rate calculated from these three I(R) parametrizations.”
On the correlations between galaxy properties and supermassive black hole mass (2011, background): “The appropriate value of α is actually a function of the Sérsic shape index n (Trujillo et al. 2004; Cappellari et al. 2006).”
HUBBLE SPACE TELESCOPE OBSERVATIONS OF SHORT GAMMA-RAY BURST HOST GALAXIES: MORPHOLOGIES, OFFSETS, AND LOCAL ENVIRONMENTS (2009, background): “This is a well-known effect for bright elliptical galaxies, which generally require a multi-parameter powerlaw plus Sérsic fit that accounts for a flatter core than expected in the de Vaucouleurs model (Trujillo et al. 2004).”
A Log-Quadratic Relation for Predicting Supermassive Black Hole Masses from the Host Bulge Sérsic Index (2006, background): “…issues can be dealt with either by simultaneously fitting a Sérsic function plus some additional function to account for the excess flux above that of the host galaxy (e.g., Graham&Guzmán 2003; Ferrarese et al. 2006a) or by using the core-Sérsic model (Graham et al. 2003b; Trujillo et al. 2004).”