A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
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
Tekijät: Toloba E., Guhathakurta P., Peletier R., Boselli A., Lisker T., Falc\'on-Barroso J., Simon J.D., van de Ven G., Paudel S., Emsellem E., Janz J., den Brok M., Gorgas J., Hensler G., Laurikainen E., Niemi S.M., R\'ys A., Salo H.
Kustantaja: Institute of Physics (IOP)
Kustannuspaikka: McMaster University, 1280 Main Street West, GSB-118C, Hamilton, ON L8S 4K1
Julkaisuvuosi: 2014
Journal: Astrophysical Journal Supplement
Lehden akronyymi: ApJS
Vuosikerta: 215
Numero: 2
Aloitussivu: 16
Lopetussivu: 66
Sivujen määrä: 51
ISSN: 0067-0049
eISSN: 0004-637X
DOI: https://doi.org/10.1088/0067-0049/215/2/17
Verkko-osoite: http://adsabs.harvard.edu/abs/2014ApJS..215...17T
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 â± 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 (H_beta and
H_gammaA ) 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 fDM = 46 ± 18%. Any
formation model for the dE galaxy class must account for this
diversity of kinematic and photometric anomalies and stellar
populations.