We test whether there is a relation between the observed tidal interactions and Seyfert activity by imaging in HI twenty inactive galaxies at the same spatial resolution and detection threshold as the Seyfert sample. This control sample of inactive galaxies were closely matched in Hubble type, range in size and inclination, and have roughly comparable galaxy optical luminosity to the Seyfert ga...

Multifractal measures are applied to three IRAS galaxy subsamples selected by colour from the PSCz catalogue. As shown by a generalised dimension spectrum, hot IRAS galaxies are found to be less clustered than cold galaxies, but the difference is very small. An alternative tool, the conditional multifractal dimension spectrum reveals an apparent peculiarity of the distribution of hot galaxies, ...

Galaxy interactions are known to trigger starbursts. The young star clusters formed in mergers may be young globular clusters. The ages of these young star clusters yield the timing of interaction-triggered star formation and provide an important way to reconstruct the history of merging galaxies. Here we present the first results from our investigation into age and metallicity of twelve young ...

Galaxy interactions are known to trigger starbursts. The young star clusters formed in mergers may be young globular clusters. The ages of these young star clusters yield the timing of interaction-triggered star formation and provide an important way to reconstruct the history of merging galaxies. Here we present the first results from our investigation into age and metallicity of twelve young ...

We present a catalog of star clusters with VF555W < 23 mag detected in the interacting spiral galaxy M51 system based on the mosaic images taken with HST ACS by the Hubble Heritage Team. We have selected about 3,600 clusters based on their morphological information through the visual inspection. The final star cluster catalog includes 2,224 clusters that are relatively well isolated and have a ...

it is inferred from the symmetrical and luminous x-ray emission of fossil groups that they are mature, relaxed galaxy systems. cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (bggs), the central early-t...

The orbital decay and tidal disruption of a star cluster in a galaxy is studied in an analytical manner. Owing to dynamical friction, the star cluster spirals in toward the center of the galaxy. Simultaneously, the galactic tidal field strips stars from the outskirts of the star cluster. Under an assumption that the star cluster undergoes a self-similar evolution, we obtain the condition and ti...

It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...

Young star clusters in interacting galaxies are often found in groups or clusters of star clusters containing up to 100 single clusters. In our project we study the future fate of these clusters of star clusters. We find that the star clusters merge on time scales of a few dynamical crossing times of the super-cluster. The resulting merger object has similarities with observed dwarf ellipticals...

We study numerically the formation of dSph galaxies. Intense star bursts, e.g. in gas-rich environments, typically produce a few to a few hundred young star clusters, within a region of just a few hundred pc. The dynamical evolution of these star clusters may explain the formation of the luminous component of dwarf spheroidal galaxies (dSph). Here we perform a numerical experiment to show that ...