J. Janz, E. Laurikainen, T. Lisker, H. Salo, R. F. Peletier, S. -M. Niemi, M. den Brok, E. Toloba, J. Falcón-Barroso, A. Boselli, G. Hensler
Early-type dwarf galaxies, once believed to be simple systems, have recently
been shown to exhibit an intriguing diversity in structure and stellar content.
To analyze this further, we started the SMAKCED project, and obtained deep
H-band images for 101 early-type dwarf galaxies in the Virgo cluster in a
brightness range of -19 \leq M_r \leq -16 mag, typically reaching a
signal-to-noise of 1 per pixel of \sim0.25" at surface brightnesses \sim22.5
mag/arcsec^2 in the H-band. Here we present the first results of decomposing
their two-dimensional light distributions. This is the first study dedicated to
early-type dwarf galaxies using the two-dimensional multi-component
decomposition approach, which has been proven to be important for giant
galaxies. Armed with this new technique, we find more structural components
than previous studies: only a quarter of the galaxies fall into the simplest
group, namely those represented by a single S\'ersic function, optionally with
a nucleus. Furthermore, we find a bar fraction of 18%. We detect also a similar
fraction of lenses which appear as shallow structures with sharp outer edges.
Galaxies with bars and lenses are found to be more concentrated towards the
Virgo galaxy center than the other sample galaxies.
View original:
http://arxiv.org/abs/1112.5203
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