The nuclear cusp slopes of dwarf elliptical galaxies

Abstract

We derive the light profiles for a sample of 25 dwarf elliptical galaxies observed by us with HST/WFPC2 in F555W and F814W. These profiles are fitted with Nuker, R^1/4, exponential, and Sersic laws, and are also used to derive the nuclear cusp slopes gamma. We discuss the correlation of nuclear cusp slope with galactic luminosity, presence of a nucleus, and type of light profile. The results are compared to those found in the literature for elliptical galaxies and the bulges of spiral galaxies. We find that as a class the nuclear regions of dwarf ellipticals are very similar to those of the exponential bulges of spiral galaxies, and have nuclear cusp slopes shallower than those of bulges that were well fitted by a de Vaucouleurs R^1/4 profile with the same luminosity. For the 14 nucleated galaxies in our sample this conclusion is less certain than for the 11 non-nucleated objects since it relies on an extrapolation of galaxy light under the nucleus. In terms of their light profiles and nuclear properties, most spheroidal stellar systems can be broadly divided into two subclasses: the exponential shallow cusp objects and the R^1/4, steep cusp objects. Membership of a class does not appear to correlate with the presence of a massive stellar disk.

arXiv comment17 pages, 6 JPEG figures, 3 Postscript figures, uses aasms4.sty to appear on Astronomical Journal

References in corpus (5)

• Spiral galaxies with WFPC2: II. The Nuclear Properties of 40 objects
• Ellipticals with Kinematically-Distinct Cores: (V-I) Color Images with WFPC2
• The Centers of Early-Type Galaxies with HST II: Empirical Models and Structural Parameters
• The Specific Globular Cluster Frequencies of Dwarf Elliptical Galaxies from the Hubble Space Telescope
• Spiral galaxies with WFPC2: III. Nuclear Cusp Slopes

Cited by in corpus (43)

• Empirical models for Dark Matter Halos. I. Nonparametric Construction of Density Profiles and Comparison with Parametric Models
• The ACS Virgo Cluster Survey. VIII. The Nuclei of Early-Type Galaxies
• HST photometry of dwarf elliptical galaxies in Coma, and an explanation for the alleged structural dichotomy between dwarf and bright elliptical galaxies
• Revised Rates of Stellar Disruption in Galactic Nuclei
• A New Empirical Model for the Structural Analysis of Early-type Galaxies and a Critical Review of the Nuker Model
• Evidence for a New Elliptical-Galaxy Paradigm: Sersic and Core Galaxies
• Quantifying the Coexistence of Massive Black Holes and Dense Nuclear Star Clusters
• Internal Dynamics, Structure and Formation of Dwarf Elliptical Galaxies: II. Rotating Versus Non-Rotating Dwarfs
• Galactic bulges from Hubble Space Telescope NICMOS observations: the lack of r^{1/4} bulges
• Weak homology of elliptical galaxies
• Internal Dynamics, Structure and Formation of Dwarf Elliptical Galaxies: I. A Keck/HST Study of Six Virgo Cluster Dwarfs
• The Colors of Dwarf Elliptical Galaxy Globular Cluster Systems, Nuclei and Stellar Halos
• Dynamics and the Origin of Low-Mass Galaxies in the Virgo Cluster
• The ACS Fornax Cluster Survey. II. The Central Brightness Profiles of Early-Type Galaxies: A Characteristic Radius on Nuclear Scales and the Transition from Central Luminosity Deficit to Excess
• Galactic Bulges from HST NICMOS Observations: central galaxian objects, and nuclear profile slopes
• Evolution of dwarf early-type galaxies I. Spatially resolved stellar populations and internal kinematics of Virgo cluster dE/dS0 galaxies
• The Fundamental Manifold of Spheroids
• The Globular Cluster Luminosity Function and Specific Frequency in Dwarf Elliptical Galaxies
• Fornax compact object survey FCOS: On the nature of Ultra Compact Dwarf galaxies
• Density-potential pairs for spherical stellar systems with Sersic light-profiles and (optional) power-law cores
• When Is a Bulge Not a Bulge? Inner Disks Masquerading as Bulges in NGC 2787 and NGC 3945
• A review of elliptical and disc galaxy structure, and modern scaling laws
• The HST/ACS Coma Cluster Survey: V - Compact Stellar Systems in the Coma Cluster
• The central density cusp of the Sagittarius dwarf spheroidal galaxy
• Empirical Models for Dark Matter Halos. III. The Kormendy relation and the log(rho_e)-log(R_e) relation
• Kinematics and Stellar Populations of Low-Luminosity Early-Type Galaxies in the Abell 496 Cluster
• On the universality of density profiles
• Dissipative transformation of non-nucleated dwarf galaxies into nucleated systems
• VLT surface photometry and isophotal analysis of early-type dwarf galaxies in the Virgo cluster
• The Void Galaxy Survey: Photometry, structure and identity of void galaxies
• Discovery of a new M32-like "Compact Elliptical" galaxy in the halo of the Abell 496 cD galaxy
• Nuclear properties of a sample of nearby spirals from STIS imaging
• Discovery of a Solitaire Dwarf Galaxy in the APPLES Survey
• Star Clusters in Virgo and Fornax Dwarf Irregular Galaxies
• $R_{\mathrm{e}}$. I. Understanding galaxy sizes, associated luminosity densities, and the artificial division of the early-type galaxy population
• Ultra-Compact Dwarfs around NGC 3258 in Antlia
• Gravitational Stability of Circumnuclear Disks in Elliptical Galaxies
• Efficiency of black hole formation via collisions in stellar systems: An analysis of data from simulations and observations
• Nuclear Star Clusters across the Hubble Sequence
• The size--mass and other structural parameter ($n,{\mu }_z,R_z$) relations for local bulges/spheroids from multicomponent decompositions
• Mirages in galaxy scaling relations
• On the unification of dwarf and giant elliptical galaxies
• Star Clusters in Pseudo-Bulges of Spiral Galaxies