Pixel-by-pixel colour-magnitude and colour-colour diagrams – based on a subset of the Hubble Space Telescope Advanced Camera for Surveys Early Release Observations – provide a powerful technique to explore and deduce the star and star cluster formation histories of the Mice and the Tadpole interacting galaxies. In each interacting system we find some 40 bright young star clusters (20 . F606W(ma...

We present the GALEX NUV (2310Å) and FUV (1530Å) galaxy luminosity functions of the nearby cluster of galaxies A1367 in the magnitude range−20.3 ≤ MAB ≤ −13.3. The luminosity functions are consistent with previous (∼ 2 mag shallower) estimates based on the FOCA and FAUST experiments, but display a steeper faint-end slope than the GALEX luminosity function for local field galaxies. Using spectro...

Observations show that galaxies follow a mass–metallicity relation over a wide range of masses. One currently favoured explanation is that less massive galaxies are less able to retain the gas and stellar ejecta and thus may lose the freshly produced metals in the form of galactic outflows. Galaxies with a low current star formation rate have been found to contain star clusters up to a lower ma...

We present a study of a faint fuzzy star cluster system in the nearby SB0 galaxy NGC 5195 interacting with the famous spiral galaxy NGC 5194 (M51), based on HST ACS BV I mosaic images taken by the Hubble Heritage Team. We have found about 50 faint fuzzy star clusters around NGC 5195 which are larger than typical globular clusters with effective radii reff > 7 pc and red with (V − I) > 1.0. They...

We observed the nearby starburst galaxy M82 in CO in the higher frequency (2–1) transition to achieve an angular resolution below 1 arc second or 17 pc at the target. We resolved the molecular gas into a large number of compact clouds, with masses ranging from ∼ 2 × 10 to 2 × 10 M⊙. The mass spectrum scales as N(M) ∝ M, similar to the mass spectra of young massive star clusters suggesting that ...

Pixel-by-pixel colour-magnitude and colour-colour diagrams – based on a subset of the Hubble Space Telescope Advanced Camera for Surveys Early Release Observations – provide a powerful technique to explore and deduce the star and star cluster formation histories of the Mice and the Tadpole interacting galaxies. In each interacting system we find some 40 bright young star clusters (20 . F606W(ma...

We review the variety of Active Galactic Nuclei (AGN) classes (so-calledAGN zoo") and classification schemes of galaxies by activity types based on their optical emission-line spectrum, as well as other parameters and other than optical wave-length ranges. A historical overview of discoveries of various types of active galaxies is given, including Seyfert galaxies, radio galaxies, QSOs, BL Lace...

We observed the nearby starburst galaxy M82 in CO in the higher frequency (2–1) transition to achieve an angular resolution below 1 arc second or 17 pc at the target. We resolved the molecular gas into a large number of compact clouds, with masses ranging from ∼ 2 × 10 to 2 × 10 M⊙. The mass spectrum scales as N(M) ∝ M, similar to the mass spectra of young massive star clusters suggesting that ...

Super star clusters” are the most massive extreme in the continuum of young star clusters. In this thesis, I examine the properties of such super star clusters in a sample of starburst galaxies with space and ground-based observations and in the optical, mid-infrared, and radio regimes. Using optical photometry, I estimate the ages and masses, as well as construct luminosity functions for the s...

The ensemble of all star clusters in a galaxy constitutes its star cluster system. In this review, the focus of the discussion is on the ability of star clusters, particularly the systems of old massive globular clusters (GCs), to mark the early evolutionary history of galaxies. I review current themes and key findings in GC research, and highlight some of the outstanding questions that are eme...