A CCD Photometric and Morphological Study of the Extended Halo and Filaments of ESO 383-45: A Galaxy Undergoing Ram Pressure Stripping, or a Tidal Merger Remnant?
We present BV CCD surface photometry, profiles, and images of the galaxy ESO 383-45, together with other galaxies in the same CCD field. We also present a B-V color map of the field and images of the galaxies enhanced by self-correlation of pixel values and by digital ``unsharp masking.'' The extended halo and system of filaments of ESO 383-45 are seen clearly. We suggest that the evidence (radio jets and their curvature and areas of diffuse optical emission) of a dense intergalactic medium (IGM) in this field toward the center of the IC 4296 cluster may indicate that the galaxy ESO 383-45 is still undergoing ram pressure stripping of its gas, forming stars in the filaments, while the central galaxy has evolved to have a lenticular morphology. On the other hand, there are ``knots'' in the filaments that look like tidal dwarf galaxies in formation, and previous simulations of the tidal interaction of two disk galaxies have produced galaxies that can resemble ESO 383-45 from certain viewing angles. Other galaxies in the field appear to lie beyond the IC 4296 cluster and may be part of sheets of galaxies previously identified as connecting the Abell clusters of the Shapley supercluster. We identify many uncataloged faint extended objects that may represent background clusters of galaxies or knots (possibly of star formation) associated with the filaments and diffuse IGM of ESO 383-45. The present work represents the first multicolor surface photometric study for all of these galaxies, and only ESO 383-45 has previously been studied morphologically, using digitally co-added Schmidt plates obtained by some of the authors.
The Astrophysical Journal
- Pub Date:
- May 2005
- Galaxies: Clusters: Individual: Alphanumeric: A3560;
- Galaxies: Clusters: Individual: Name: A3565;
- Galaxies: Evolution;
- Galaxies: Interactions;
- Galaxies: Peculiar;
- Galaxies: Photometry;
- Galaxies: Intergalactic Medium