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Collaborators of Dr. Gregg are listed below

Michael Gregg

Michael Gregg
(UC Davis)

Michael Gregg is an Associate Research Astrophysicist in the Department of Physics at the University of California, Davis, but he spends most of his professional time at the Institute for Geophysics and Planetary Physics at the Lawrence Livermore National Laboratory. Michael started his career investigating the stellar population of relatively nearby S0 galaxies, showing that they may have evolved from spiral galaxies. This work spawned investigations of nearby galaxy clusters.

His collaboration with Michael Drinkwater (U.Queensland) on the Fornax and Virgo clusters has discovered "ultra-compact dwarfs'' the first new type of galaxy to be discovered since Edwin Hubble laid out the original galaxy classification scheme in the 1930's. With Michael West (U. Hawaii, Hilo), he is studying the remains of recently destroyed galaxies in the Coma and Centaurus clusters. Much of this nearby galaxy work is done using the Hubble Space Telescope. At the other end of the Universe, Michael searches for gravitationally lensed quasars and more exotic types of quasars nearly buried by dust or having unusual radio-emitting properties.

Michael was born in Long Beach, California, but spent most of his childhood roaming the outdoors of Western Pennsylvania, where the skies are still dark enough to inspire appreciation of the heavens. An undergraduate double major in physics and philosophy at Haverford College, he worked for a summer with R. Bruce Partridge in that institution's antique Strawbridge Observatory. This led to further astronomical studies and a Ph.D. at Yale University where he was fortunate enough to get to know the late Beatrice Tinsley while generating the idea for his dissertation. He has since lived and worked in Pasadena, Chapel Hill, and Canberra (Australia), before beginning his longer term association with U.C. Davis and IGPP/LLNL in 1993. Early in his professional journey, he married Abbie Rockwell, an elementary school music teacher. They are raising three precocious daughters in a sturdy 120 year old house on the south side of old Livermore.


Michael Drinkwater

Michael Drinkwater (University of Queensland, Australia)

I obtained my B.Sc. (1984) from the University of Sydney and my Ph.D. (1988) from the University of Cambridge with a thesis on quasar clustering. From 1988-1991 I was a Research Associate at the Université Laval in Québec City, Canada. Here I worked on quasar absorption line systems, dwarf galaxies, and the liquid mirror project. I also learnt to ski and speak French fluently. From 1991-1996, I was a Staff Astronomer at the Anglo-Australian Observatory My observatory work focused on completion of the "second epoch" photographic sky survey, based at the U.K. Schmidt Telescope. For research I mainly worked on dwarf galaxy studies in the Virgo and Fornax clusters as well as a new sample of quasars from the Parkes radio telescope. I was a Research Fellow at the University of New South Wales from1996-1999. At UNSW I started the "Fornax Cluster Spectroscopic Survey" using the 2dF spectrograph on the Anglo-Australian Telescope. I also became a proud father in 1999. In 1999 I moved to the University of Melbourne where I became a Senior Research Fellow. I led the discovery of a new type of galaxy, "ultra-compact dwarf galaxies" (UCDs) while at Melbourne, which we then investigated further using the Hubble Space Telescope. Since 2002 I have been a Senior Lecturer at the University of Queensland.


Bradford Holden
(UCO/Lick Observatory)

Academic Background includes: Ph. D. (Astronomy and Astrophysics), University of Chicago, 1999; M. Sc. (Astronomy and Astrophysics), University of Chicago, 1994; B. A. (Physics) with Honors and Thesis Honors, University of California, Santa Cruz, 1993. Thesis - "The Dependence of the Mass-Luminosity Relation on Metallicity.''

Research Interests include Surveys for High Redshift Clusters of Galaxies; Origin of the Intracluster Medium; and Stellar Populations of Early-Type Galaxies

I observationally study clusters of galaxies and the early-type galaxies in those clusters. My goal is to make physical measurements with the goal of comparing those values with model predictions. An example of this can be found in my Fundamental Plane paper, astro-ph/0412570, where I measure sizes and velocity dispersions of massive cluster members.

I am a member of the ACS Science team. I am working at UC, Santa Cruz on the intermediate redshift cluster program. We are studying the galaxy members of clusters in the redshift range of 0.8 to 1.3, selected using the ROSAT Deep Cluster Survey, which is a survey I have worked on previously, along with clusters from other sources such as the Gunn, Hoessel, and Oke catalog.

One of the fields in the RDCS has been in the news lately. The Lynx field, which contains four different clusters has an unusual gravitational arc.

Previously I worked with Adam Stanford. With him, I worked on studying the ROSAT Deep Cluster Survey and the infrared survey of Stanford, Eisenhardt and Dickinson. This project yielded the following monstrous tome.


Michael Hilker

Michael Hilker
(University of Bonn)

Since May 2001 I am a research assistant at the Sternwarte (Observatory) of the University of Bonn. Half of my time I spend in the Satellite Project DIVA, especially in the spectrophotometric aspects of this program. The other half of my time I follow the research lines as listed below and participate in the education and supervision of undergraduate and graduate students (see the available diplomathesis topics). Also I am a member in the Graduiertenkolleg about "Galaxy Groups as Laboartories for Baryonic and Dark Matter''. Before my position in Bonn I have been working as a post-doc in the department of astronomy and astrophysics of the Universidad Católica in Santiago de Chile. My position there was granted by FONDECYT (CONICYT) and my supervisor was Prof. Dr. L. Infante. My Ph.D. thesis In February 1998 I completed my Ph.D. thesis at the Sternwarte Bonn in February 1998. The subject of my thesis is: "The center of the Fornax cluster: dwarf galaxies, cD halo, and globular clusters'', supervised by Priv.Doz. Dr. Tom Richtler. During my Ph.D. research I was partly involved in the Graduiertenkolleg about "The Magellanic System and Other Dwarf Galaxies'."


Julio Chaname

Julio Chaname
(Ohio State)

Julio Chaname received his B.S. in 1994, from the Pontificia Universidad Catolica in Peru and his M.S. in 2000 from the Pontificia Universidad Catolica in Chile, where his thesis included a dynamical study of NGC 1427A and its relationship with the environment of the Fornax cluster. He is currently working on a Ph.D. at the Ohio State University Department of Astronomy with interests in the formation of the Milky Way and the Local Group, the nature of the dark matter in the halo of the Galaxy, the dynamics of stellar systems, and the theory of stellar structure and evolution. After graduation in August 2005 he will be moving to the STScI as a Postdoctoral Fellow.