TY - JOUR
T1 - More evidence for hidden spiral and bar features in bright early-type dwarf galaxies
AU - Barazza, F. D.
AU - Binggeli, B.
AU - Jerjen, H.
PY - 2002/9
Y1 - 2002/9
N2 - Following the discovery of spiral structure in IC 3328 (Jerjen et al. 2000), we present further evidence that a sizable fraction of bright early-type dwarfs in the Virgo cluster are genuine disk galaxies, or are hosting a disk component. Among a sample of 23 nucleated dwarf ellipticals and dSOs observed with the Very Large Telescope in B and R, we found another four systems exhibiting non-axisymmetric structures, such as a bar and/or spiral arms, indicative of a disk (IC 0783, IC 3349, NGC 4431, IC 3468). Particularly remarkable are the two-armed spiral pattern in IC 0783 and the bar and trailing arms in NGC 4431. For both galaxies the disk nature has recently been confirmed by a rotation velocity measurement (Simien & Prugniel 2002). Our photometric search is based on a Fourier decomposition method and a specific version of unsharp masking. Some "early-type" dwarfs in the Virgo cluster seem to be former late-type galaxies which were transformed to early-type morphology, e.g. by "harassment", during their infall to the cluster, while maintaining part of their disk structure.
AB - Following the discovery of spiral structure in IC 3328 (Jerjen et al. 2000), we present further evidence that a sizable fraction of bright early-type dwarfs in the Virgo cluster are genuine disk galaxies, or are hosting a disk component. Among a sample of 23 nucleated dwarf ellipticals and dSOs observed with the Very Large Telescope in B and R, we found another four systems exhibiting non-axisymmetric structures, such as a bar and/or spiral arms, indicative of a disk (IC 0783, IC 3349, NGC 4431, IC 3468). Particularly remarkable are the two-armed spiral pattern in IC 0783 and the bar and trailing arms in NGC 4431. For both galaxies the disk nature has recently been confirmed by a rotation velocity measurement (Simien & Prugniel 2002). Our photometric search is based on a Fourier decomposition method and a specific version of unsharp masking. Some "early-type" dwarfs in the Virgo cluster seem to be former late-type galaxies which were transformed to early-type morphology, e.g. by "harassment", during their infall to the cluster, while maintaining part of their disk structure.
KW - Galaxies: fundamental parameters
KW - Galaxies: general
KW - Galaxies: photometry
KW - Galaxies: structure
UR - http://www.scopus.com/inward/record.url?scp=0036728638&partnerID=8YFLogxK
U2 - 10.1051/0004-6361:20020875
DO - 10.1051/0004-6361:20020875
M3 - Article
SN - 0004-6361
VL - 391
SP - 823
EP - 831
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 3
ER -