Tammy A. Smecker-Hane Assistant Professor of Physics (astrophysics)  Room 4109C, Frederick Reines Hall  Phone: (949) 824-7773  Fax: (949) 824-2174  E-mail: tsmecker@uci.edu

Professor Smecker-Hane earned her B.A. (1988) and Ph.D. (1993) from Johns Hopkins University. Her dissertation research involved theoretical modeling of the formation and evolution of our Galaxy, with particular emphasis on using observations of the chemical abundances of Galactic stars to gain new insight on the formation of the Galactic halo, disk and bulge. She was NATO-NSF post doctoral fellow (1993) and later a research associate (1994-5) at the Dominion Astrophysical Observatory in Victoria, British Columbia, which is operated by the National Research Council of Canada. She joined the faculty of UCI in the fall of 1995.

Professor Smecker-Hane's research interests are in the formation and evolution of galaxies, and she does both theoretical and observational work in these areas. Some examples include:

• Developing theoretical models and numerical simulations of the evolution of the star formation rate, chemical element abundances and dynamics of galaxies.
• Determining ages and chemical abundances of stars in our Galaxy and in its nearby neighbors (the Ursa Minor, Carina, Fornax, Sculptor, Sagittarius dwarf spheroidal galaxies and the Large and Small Magellanic Clouds) using high-precision photometry, and low and high-dispersion spectroscopy obtained with telescopes at the Cerro Tololo Interamerican Observatory in Chile, the Keck 10-meter Telescope in Hawaii, and the Hubble Space Telescope.
• Estimating the timescale on which the central bulge of our Galaxy formed by measuring the distribution of iron abundance in Galactic bulge stars, and the behavior of chemical abundance ratios such as [Ca/Fe] as a function of iron abundance, using high resolution spectroscopy obtained with the multifiber spectrograph on the 4-meter telescope at the Cerro Tololo Interamerican Observatory.
• Developing theoretical models to understand the physical mechanisms that control the evolution of the star-formation rate, chemical compositions, and dynamics of galaxies, and defining the roles that supernova-driven galactic winds and massive dark matter halos play in shaping the evolution of galaxies.
• Searching for super-star clusters and determining their ages, luminosities, sizes, densities and masses. Super-star clusters are extremely dense clusters of a few million stars which may (or may not) be analogs to young globular clusters. They represent a rare mode of star formation that appears to be triggered when a galaxy undergoes an intense burst of star formation (for example, as a result of an interaction or collision with another galaxy). Studies of these star clusters will give us valuable insight into globular cluster formation, and also may help quantify the differences in the formation histories of elliptical versus spiral galaxies.
• Determining the mass and shape of dark matter halos in elliptical galaxies by mapping the stellar velocity field, and measuring radial gradients in the ages and chemical abundances of their stars.
• Exploring the star-formation history of distant galaxies which are members of rich galaxy clusters at intermediate redshifts (0.2 < z < 0.5) using the measured colors and spectral line strengths of galaxies in the Canadian Network for Observational Cosmology (CNOC) redshift survey.

Publications On-Line at the LANL Server

Recent Conference Papers:

• "Ages and Chemistry in Dwarf Spheroidal Galaxies", Smecker-Hane, T. A. & McWilliam, A.,  in Spectro-Photometric Dating of Stars and Galaxies, eds. I. Hubeny, S. Heap & R. Cornett, (ASP: San Francisco), ASP Conf. Series, in press (1999)
• "The Chemical Abundances in the Carina Dwarf Spheroidal Galaxy",  Smecker-Hane, T. A., et al.,  in Spectro-Photometric Dating of Stars and Galaxies, eds. I. Hubeny, S. Heap & R. Cornett, (ASP: San Francisco), ASP Conf. Series,  in press (1999)
• "New Photometric Surveys of the Fornax Dwarf Spheroidal Galaxy", Smecker-Hane, Stetson & Hesser, to appear in The Stellar Content of Local Group Galaxies, ed. P. Whitlock & R. Cannon, (ASP: San Francisco), ASP Conf. Series, 192, 11 (1999)
• "A Photometric Survey of Field Stars in the Large Magellanic Cloud: Probing its Star-Formation History", Smecker-Hane, Gallagher, Cole, Stetson & Tolstoy, to appear in New Views of the Magellanic Clouds, eds. Y.-H. Chu, N. Suntzeff, J. Hesser & D. Bohlender, (ASP: San Francisco), ASP Conf. Series, 190, 117 (1999)
• "Field Star Formation History of the Large Magellanic Cloud", Gallagher, Cole, Holtzman, & Smecker-Hane, to appear in New Views of the Magellanic Clouds, IAU Symp. 190, eds. Y.-H. Chu, N. Suntzeff, J. Hesser & D. Bohlender (ASP: San Francisco), ASP Conf. Series, 190, 29 (1999).

On-Line Seminar Talks:

• Colloquium given at the Space Telescope Science Institute, Baltimore, Maryland, in April, 2003, entitled "Star Formation Histories and Chemical Abundances of Local Group Dwarf Galaxies" (click on the title to play the webcast)
• Invited review talk entitled "Chemical Abundances from Low Resolution Spectroscopy of Dwarf Galaxies" (Powerpoint w/ audio) given at the Ringberg Workshop on "The Chemical Evolution of Dwarf Galaxies - Present Status and Perspectives" held in July, 2002

Representative Publications:

• "The Star Formation History of the Large Magellanic Cloud", Smecker-Hane, T. A., Cole, A. A., Gallagher, J. S. III & Stetson, P. B. (2001), Astrophysical Journal, in press
• "The Metallicity Distribution Function of Red Giants in the LMC", Cole, A. A., Smecker-Hane, T. A. & Gallagher, J. S. III, Astronomical Journal, 120, 1808 (2000).
• "The Star Clusters in the Starburst Irregular Galaxy NGC 1569", Hunter, D. A., O'Connell, R. W., Gallagher, J. S. & Smecker-Hane, T. A., Astronomical Journal, 120, 2383 (2000).
• "The Star Formation Histories of Dwarf Spheroidal Galaxies", Smecker-Hane, T., in Star Formation, Near and Far , eds. S. Holt and L.G. Mundy, (AIP: New York), AIP Conf. Proceedings, in press (1997).
• `"Homogeneous Photometry for Star Clusters and Resolved Galaxies. I. A Survey of Bright Stars in the Fornax Dwarf Spheroidal Galaxy", Stetson, P. B., Hesser, J. E. & Smecker-Hane, T. A., ', PASP, 110, 533-552 (1998)
• "Episodic Star Formation in the Carina dSph Galaxy", Smecker-Hane, T.A., Stetson, P.B., Hesser, J.E. & VandenBerg, D.A., in From Stars to Galaxies: The Impact of Stellar Physics on Galaxy Evolution , eds. C. Leitherer, U. Fritze-von Alvensleben and J. Huchra, (ASP: San Francisco), ASP Conf. Series. vol. 98, p. 328 (1996).
• "The Stellar Population of the Carina Dwarf Spheroidal Galaxy: I. A New Color-Magnitude Diagram for the Giant and Horizontal Branches", Smecker-Hane, Stetson, Hesser & Lehnert, Astron. Jour., 108, 507 (1994).
• "The Post-Merger Elliptical NGC 1700: Stellar Kinematics to Four Effective Radii", Statler, T.S., Smecker-Hane, T.A. & Cecil, G.N., Astronomical Journal, 111, 1512 (1996).
• "The Dynamical Equilibrium of Galaxy Clusters", Carlberg, R.G., Yee, H.K.C., Ellingson, E., Morris, S., Abraham, R., Gravel, P., Pritchet, C.J., Smecker-Hane, T., Hartwick, F.D.A., Hesser, J.E., Hutchings, J.B. & Oke, J.B., Astrophysical Journal Letters, in press (1996).
• "The CNOC Cluster Redshift Survey Catalogs II. Abell 2390", Yee, H.K.C., Ellingson, E., Abraham, R., Gravel, P., Carlberg, R.G., Smecker-Hane, T.A., Shade, D. & Rigler, M., Astrophysical Journal Supplements, 102, 289 (1996).
• "Galaxy Evolution in ABELL 2390", Abraham, R.G., Smecker-Hane, T.A., Hutchings, J.B., Carlberg, R.G., Yee, H.K.C., Ellingson, E., Morris, S., Oke, J.B. & Rigler, M., Astrophysical Journal, 471, 694 (1996).
• "Type Ia Supernovae and the Duration of the Formation of the Galactic Stellar Halo", Smecker-Hane & Wyse, Astron. Jour., 103, 1621 (1992).

Links to Other Collaborative Research Projects

• Canadian Network for Observational Cosmology (CNOC)