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Astrophysics Group > Home
Visiting
and Other Faculty:
Emeritus
Faculty: Poirier
Astrophysics
research at Notre Dame is directed toward the study of astrophysical
origins. The group's activities contribute to the recently established
Center for Astrophysics at Notre Dame University (CANDU). The center
supports inter-disciplinary research in three basic areas: theoretical
astrophysics and cosmology, ground-based optical astronomy, and
space science.
Ground-Based
Astronomy
The
flagship of Notre Dame's ground-based observational effort is the
partnership with the Large Binocular Telescope (LBT) in Arizona.
Notre Dame has joined a consortium of other universities for construction
and use of this telescope. The members of this consortium are excitedly
anticipating the arrival of first light in early 2004. The LBT will
be one of the most powerful and versatile telescopes in the world.
It will be the premier instrument for many astronomical problems
ranging from studies of the early universe to searches for planets
in other star systems.
Current
observational programs involve a variety of telescopes around the
world including the Keck observatory in Hawaii and the
Hubble Space Telescope. Ongoing research includes studies in the
mysterious dark energy which is accelerating the expansion rate
of the universe, studies of distant supernovae and gamma-ray bursts,
studies of planet formation in young stellar systems, and studies
of gravitational microlensing to search for dark matter and planets
in the Galaxy.
Theoretical
Research
Ongoing
theoretical research includes all aspects of the origin and evolution
of the universe, galaxies, stars, planets, and the interstellar
medium. The astrophysics theory group has pioneered the development
of modern numerical methods for hydrodynamic simulations of complex
astrophysical systems. Theoretical work concerning the formation
and evolution of galaxies, stars and the interstellar medium is
being investigated with complex adaptive mesh magnetohydrodynamics.
The group is also doing cosmological simulations of the origin and
evolution of the very early universe, from the birth at the Planck
scale, through inflation and various particle-physics processes,
primordial nucleosynthesis, the emission of the cosmic microwave
background, and the formation of large-scale structure and galaxies.
These simulations are used to constrain theories for the nature
of space-time and the origin of the universe. General relativistic
numerical hydrodynamic simulations are also being performed as a
means to understand exploding supernovae, black-hole and neutron
star formation, and the formation of jets and electromagnetic bursts
from accreting systems.
Another
focus is theoretical nuclear astrophysics. This includes nucleosynthesis
in the big bang, in supermassive population III stars, during late
stellar evolution (AGB stars), and explosive nucleosynthesis on
accreting white dwarfs (novae), accreting neutron stars (X-ray bursts),
and supernovae. The nucleosynthesis is simulated using complex nuclear
reaction network models for stellar hydrostatic and/or hydrodynamic
conditions. The nuclear-physics input is derived from nuclear structure
and nuclear reaction models. The reaction flow is studied within
the time scales of static or explosive stellar burning. Energy generation
and nucleosynthesis are calculated and compared with observed luminosities
and elemental abundance distributions.
Space
Science
Research
in space science divides into studies of cosmic-ray air showers
and the development of a new Notre-Dame satellite mission. In cosmic-ray
research, an extensive air shower array (Project GRAND) is used
to study cosmic rays and measure angles with high precision. The
production mechanisms for UHE cosmic gamma rays and stellar sources
such as Cygnus X-3 and Hercules X-1 are being studied along with
a search for an association with gamma-ray bursts.
The group's newest endeavor
is the proposed Deep Impact Microlensing Explorer Mission (DIME) in
which Notre Dame's contribution will be as the Science Analysis center.
Scientists at Notre Dame will utilize the onboard telescope to make
parallax measurements of distant gravitational microlensing events.
These observations will be crucial to characterize the nature of dark
matter in the Galaxy.
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