Gregory D. Wirth

Postdoctoral Research Associate
Department of Physics & Astronomy
University of Victoria

Research Interests:


The Nature of Early-Type Galaxies at the z=0.5 Epoch
My thesis explores galaxy evolution by observing one of the most distant and most interesting clusters of galaxies, known as Cl0016+16. Because of their great distance, we see the galaxies in this cluster as they were nearly 6 billion years ago, roughly halfway back to the time of the Big Bang. The observations include pictures taken with the Hubble Space Telescope (HST) and spectra made with the giant new Keck 10-meter telescope in Hawaii. By measuring properties such as the luminosity, size, surface brightness, age, composition, and mass of the galaxies in Cl0016+16, we can determine how galaxies have evolved since then by comparing to present-day counterparts.

Slide Gallery:


HST Observations of the Distant Cluster Cl 0016+16: Quantitative Morphology of Confirmed Cluster Members
Wirth, G. D., Koo, D. C., & Kron, R. G.
1994, Astrophysical Journal (Letters), 435, L105
See also: Preprint version
A Search for X-ray Bright Clusters of Galaxies
Nichol, R. C., Ulmer, M. P., Kron, R. G., Wirth, G. D., & Koo, D. C.
1994, Astrophysical Journal, 432, 464
HST Images of Very Compact Blue Galaxies at z~0.2
Koo, D. C., Bershady, M. A., Wirth, G. D., Stanford, S. A., & Majewski, S. R.
1994, Astrophysical Journal, 427, L9
Photometry Strategies for Distant Clusters
Wirth, G. D., Koo, D. C., & Bershady, M. A.
Presented at Quantifying Galaxy Morphology at High Redshift, a workshop held at the Space Telescope Science Institute, Baltimore MD, 27-29 April, 1994
Quantitative Results From WF/PC Imaging Of The Distant, Rich Cluster 0016+16
Wirth, G. D.
Presented at the XIVth Moriond Astrophysics Meeting: Clusters of Galaxies, Meribel, Savoie, France, 12-19 March 1994
Clusters in Collision?
Ulmer, M. P., Wirth, G. D., & Kowalski, M. P.
1992, Astrophysical Journal, 397, 430
The Behavior of Magnesium and Sodium Lines Among Giants Within Bimodal-CN Globular Clusters
Smith, G. H., & Wirth, G. D.
1991, Publications of the Astronomical Socity of the Pacific, 103, 1158

Observing Aids:

Click here to browse through a compendium of useful stuff for observing at Lick Observatory.

Mel Ulmer's Credo:

The hardest "job" for a scientist is determining an interesting project that is possible to do. Questions that should always be asked are:
  1. What if I am successful --- so what?
  2. If I get a negative result will this still be useful?
  3. How long will this project take? [note: time==money]
  4. Do I have the resources to do the job?
  5. Do I want to allocate my resources for this task?
  6. Why hasn't anybody done this project before/who might be working on it right now?
  7. Whatever techniques I use, what kind of uncertainties are likely and how will I be able to cross-check my results?

Dave Meyer's Credo:

``If you're not miserable, you're not working hard enough.''

Geoffrey Bryden's Credo:

``Sandwiches bring out the wurst in people.''
Gregory D. Wirth <>
Last modified: Sat Apr 19 13:23:58 1997