Stellar Kinematics and Structural Properties of Virgo Cluster Dwarf Early-type Galaxies from the SMAKCED Project. II. The Survey and a Systematic Analysis of Kinematic Anomalies and Asymmetries

Autor(en)

E. Toloba, P. Guhathakurta, R. F. Peletier, A. Boselli, T. Lisker, J. Falcón-Barroso, J. D. Simon, G. van de Ven, S. Paudel, E. Emsellem, J. Janz, M. den Brok, J. Gorgas, G. Hensler, E. Laurikainen, S.-M. Niemi, A. Ryś, H. Salo

Abstrakt

We present spatially resolved kinematics and global stellar populations

and mass-to-light ratios for a sample of 39 dwarf early-type (dE)

galaxies in the Virgo cluster studied as part of the SMAKCED stellar

absorption-line spectroscopy and imaging survey. This sample is

representative of the early-type population in the Virgo cluster in the

absolute magnitude range -19.0 <Mr <-16.0

and of all morphological subclasses found in this galaxy population. For

each dE, we measure the rotation curve and velocity dispersion profile

and fit an analytic function to the rotation curve. We study the

significance of the departure of the rotation curve from the best-fit

analytic function (poorly fit) and of the difference between the

approaching and receding sides of the rotation curve (asymmetry). Our

sample includes two dEs with kinematically decoupled cores that have

been previously reported. We find that 62 ± 8% (23 out of the 39)

of the dEs have a significant anomaly in their rotation curve. Analysis

of the images reveals photometric anomalies for most galaxies. However,

there is no clear correlation between the significance of the

photometric and kinematic anomalies. We measure age-sensitive

(Hβ and HγA ) and metallicity sensitive

(Fe4668 and Mgb) Lick spectral indices in the LIS-5 Å system. This

population of galaxies exhibits a wide range of ages and metallicities;

we also find that 4 dEs show clear evidence of emission partially

filling in the Balmer absorption lines. Finally, we estimate the total

masses and dark matter fractions of the dEs and plot them in the

mass-size, the mass-velocity dispersion, and the fundamental plane

scaling relations. The dEs seem to be the bridge between massive

early-type galaxies and dSphs, and have a median total mass within the

Re of log Me = 9.1 ± 0.2 and a median dark

matter fraction within the Re of f DM = 46

± 18%. Any formation model for the dE galaxy class must account

for this diversity of kinematic and photometric anomalies and stellar

populations.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

University of California, Santa Cruz, Carnegie Institution for Science, University of Groningen, Aix-Marseille Université, Universität Heidelberg, Instituto de Astrofísica de Canarias (IAC), Universidad de La Laguna, Max-Planck-Institut für Astronomie, Korea Astronomy and Space Science Institute, European Southern Observatory (Germany), Université Claude-Bernard-Lyon-I, Swinburne University of Technology, University of Utah, Universidad Complutense De Madrid, University of Oulu, University of Turku, University College London

Journal

The Astrophysical Journal Supplement Series

Band

215

ISSN

0067-0049

Publikationsdatum

12-2014

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/2d6ce57c-36da-436d-a1be-7f335e0a97c4