Research
My research interests are focussed mainly on the morphology and dynamics of galaxies, with a special emphasis on ringed and barred galaxies. I have also been involved in the construction of large galaxy catalogues. I have used several telescopes at some of the world's finest observatories for my research.
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The secondary mirror assembly of the TNG 3.6-m telescope located on La Palma, in the Canary Islands.
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Galaxies
Spiral Galaxy NGC 4274 (Picture from cseligman.com)
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Galaxies are massive systems of stars, gas, dust, and other forms of matter bound together gravitationally as a single physical unit. Based on deep imaging surveys, it can be estimated that the Universe includes more than 40 billion galaxies, spread around in complex large- scale structures, such as clusters, superclusters, and the boundaries of large, empty regions called voids. Our Sun is part of what we call the Milky Way Galaxy, which is a highly flattened spiral galaxy containing perhaps as many as 400 billion stars. With large telescopes, we can see galaxies in most directions populating even the remotest regions of the Universe.
Understanding galaxies is an important part of modern astronomy. Galaxies are fundamental units of matter in space, and determining how they formed and achieved their current state is of critical importance to many issues in astronomy. This is the basis for much of my research in astronomy. My focus is mainly on galaxy morphology and dynamics, mostly from an observational emphasis. |
Here are some topics I have worked on:
- Compilation (all or part) of two major galaxy catalogues: The Third Reference Catalogue of Bright Galaxies, and The Catalogue of Southern Ringed Galaxies
- The Structure and Dynamics of Ringed Galaxies, my PhD thesis under the supervision of Prof. Gerard de Vaucouleurs (1918-1995), plus the Astrophysical Journal papers in 1986-1988 that came out of it
- Photoelectric photometry of DDO dwarfs and other galaxies with Gerard and Antoinette de Vaucouleurs
- External galaxies in the Zone of Avoidance; Photometric study of major members of the IC 342/Maffei Galaxy Group
- Quantitative studies of bar strength in galaxies (current); the distribution of bar strengths in galaxies; bulges and disks