E-mail: bennett.27@nd.edu
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Assistant Professor
Experimental and Theoretical Astrophysics and Cosmology.
B.S., 1981, Case Western Reserve University
Ph.D., 1986, Stanford University
My main research effort is in the new and rapidly growing field of gravitational microlensing. By regularly observing millions of stars in the Large Magellanic Cloud (a close neighbor galaxy) and the Galactic bulge it is possible to observe instances of gravitational microlensing in which the gravitational field of a dark or dim foreground object serves as a lens to magnify the apparent brightness of a brighter source star. With my colleagues on the MACHO project, I have used this gravitational microlensing technique to study the structure of our Galaxy and the composition of the dark matter which dominates the mass of our Galaxy. Our latest results suggest that we have discovered at least some of the Galactic dark matter in the form of MAssive Compact Halo Objects (or MACHOs) with a mass between 0.1 and 1 solar mass. It is possible that these MACHOs are white dwarf stars.
I am also working on applying the gravitational microlensing to the search for extra-solar planetary systems. In collaboration with Prof. Sun Hong Rhie , I have shown that microlensing is the only known ground based planet search technique that is sensitive to planets with masses as small as that of the Earth. The planet detection program requires more frequent observations of microlensing events from a network of telescopes on several continents in the Southern Hemisphere. We are currently working to set up a planet search telescope network which we expect to become operational in mid-1997.
In addition to these experimental efforts, I also work on theoretical cosmology. I am particularly interested in the observational consequences of early universe models for the formation of large scale structure. At present I am concentrating my efforts on predictions of the Cosmic Microwave Background Radiation Anisotropy that can be observed by the MAP and Plank (formerly COBRAS/SAMBA) satellites that have recently been approved by NASA and ESA.
I also have interests in a number of other topics such as gamma ray bursts, galactic structure, and variable stars.
Selected Publications:
"The MACHO Project LMC Microlensing Results from the First Two Years and the Nature of the Galactic Dark Halo", C. Alcock, R.A. Allsman, D. Alves, T.S. Axelrod, A.C. Becker, D.P. Bennett, K.H. Cook, K.C. Freeman, K. Griest, J. Guern, M.J. Lehner, S.L. Marshall, B.A. Peterson, M.R. Pratt, P.J. Quinn, A.W. Rodgers, C.W. Stubbs, W. Sutherland, D.L. Welch (The MACHO Collaboration), Ap. J., 486, 697 (1997) ( astro-ph/9606134).
"The Macho Project: 45 Candidate Microlensing Events from the First Year Galactic Bulge Data", C. Alcock, R.A. Allsman, D. Alves, T.S. Axelrod, D.P. Bennett, K.H. Cook, K.C. Freeman, K. Griest, J. Guern, M.J. Lehner, S.L. Marshall, H.-S. Park, S. Perlmutter, B.A. Peterson, M.R. Pratt, P.J. Quinn, A.W. Rodgers, C.W. Stubbs, W. Sutherland (The MACHO Collaboration), Ap. J., 479, 119 (1997) ( astro-ph/9512146).
"Detecting Earth-Mass Planets with Gravitational Microlensing", D.P. Bennett and Sun Hong Rhie, Ap. J., 472, 660 (1996) ( astro-ph/9603158).
"Is There Evidence for Repeating Gamma Ray Bursters in the BATSE Data?", D.P. Bennett and Sun Hong Rhie, Ap. J., 458, 293, (1996).
"COBE's Constraints on the Global Monopole and Texture Theories of Cosmic Structure Formation", D.P. Bennett and Sun Hong Rhie, Ap. J. Lett. 406, L7 (1993).
"The Implications of the COBE-DMR Results for for Cosmic Strings", D.P. Bennett, F.R. Bouchet, and A. Stebbins, Ap. J. Lett. 399, L11 (1992).
E-mail: bennett.27@nd.edu
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