Analyzing global starburst properties in various kinds of starburst and post-starburst galaxies and relating them to the properties of the star cluster populations they form, I explore the conditions for the formation of massive, compact, long-lived star clusters. The aim is to find out whether the relative amount of star formation that goes into star cluster formation as opposed to field star ...

In this talk I discuss the role of proto-globular clusters as the dominant sources of radiation that reionised hydrogen in the intergalactic medium (IGM) at redshift z ∼ 6. Observations at lower redshift indicate that only a small fraction, 〈fesc〉, of hydrogen ionising radiation emitted from massive stars can escape unabsorbed by the galaxy into the IGM. High redshift galaxies are expected to b...

We present ultraviolet (UV) images of nine starburst galaxies obtained with the Hubble Space Telescope using the Faint Object Camera. The galaxies range in morphology from blue compact dwarfs to ultra-luminous merging far-infrared galaxies. Our data combined with new and archival UV spectroscopy and far-infrared fluxes allow us to dissect the anatomy of starbursts in terms of the distributions ...

We present an extensive photometric and spectroscopic study of two high-redshift clusters of galaxies based on data obtained from the Keck 10m telescopes and the Hubble Space Telescope. The clusters CL0023+0423 (z = 0.84) and CL1604+4304 (z = 0.90) are part of a multi-wavelength program to study nine candidate clusters at z > ∼ 0.6 (Oke, Postman & Lubin 1998). Based on these observations, we st...

Deep VLA 1.4 GHz radio continuum imaging of Abell 2255 is presented. This cluster is among the better nearby candidates for rich cluster-cluster merger systems, with evidence including an elongated X-ray morphology, the presence of a radio halo, and substructure present in its galaxy distribution. Our radio observations reach an rms sensitivity of ∼ 40μJy beam, enabling us to detect (at 5σ) sta...

A large fraction of bulgeless disk galaxies contain young compact stellar systems at their centers, in spite of the local gravitational stability of these disks. We evaluate two contrasting hypotheses for the origin of the nuclear star clusters in late-type disk galaxies. The clusters could not have migrated from distant eccentric locations in the disk. Instead they must have formed in situ, re...

Evolutionary synthesis models for star clusters of various metallicities including gaseous emission during the lifetime of the ionising stars are used to model star cluster systems comprising two populations: an old metal-poor globular clusters (GC) population similar to that of the Milky Way halo and a second GC population of arbitrary metallicity. We investigate the time evolution of color di...

Spectacular images of colliding galaxies like the "Antennae", taken with the Hubble Space Telescope, have revealed that a burst of star/cluster formation occurs whenever gas-rich galaxies interact. The ages and locations of these clusters reveal the interaction history and provide crucial clues to the process of star formation in galaxies. We propose to carry out state-of-theart numerical simul...

We present a preliminary study of using the template of an ensemble of evolving shells we developed for M 82 (Yao 2009). we apply the model to represent various stages of starburst evolution in a well known sample of nearby luminous infrared galaxies (LIRGs). In this way, we attempt to interpret the relationship between the degree of molecular excitation and ratio of far-infrared (FIR) to CO lu...

We use high-resolution near-infrared spectroscopy from Keck Observatory to measure the stellar velocity dispersions of 19 super star clusters (SSCs) in the nuclear starburst of M82. The clusters have ages on the order of 10 Myr, which is many times longer than the crossing times implied by their velocity dispersions and radii. We therefore apply the Virial Theorem to derive the kinematic mass f...