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NORTH CAROLINA STATE UNIVERSITY
DEPARTMENT OF PHYSICS
Astrophysics
BlondinBorkowskiBrownEllisonFröhlichKnellerLazzatiMcLaughlinReynolds
Overview
The astrophysics group at North Carolina State
University investigates a range of topics within the
broad category of high-energy astrophysics. Research
includes observations with space-based observatories,
analytical and numerical modeling, and large-scale
numerical simulations. In addition to work described
below, topics include Big Bang nucleosynthesis,
galactic chemical evolution, stellar winds, interacting
binary stars, accretion disks, and pulsar wind nebulae.
Our research is funded by NASA, NSF, and DOE.
nuclear matter, plasma dynamics, and neutrino
transport. Profs. Kneller and McLaughlin study the
evolving flavor composition of neutrinos as they
propagate through supernovae and how various
mechanisms that drive that evolution manifest
themselves in the signal expected when we next detect
the burst from a galactic supernova. From this signal
one can hope to tease out the unknown properties of
the neutrino such as the ordering of the neutrino
masses, the size of the last mixing angle and the CP
phase.
Research Areas
Supernovae and Gamma-Ray Bursts represent
the most violent explosions in our universe. The
gravitational collapse of the stellar core in both of
these events is expected to break spherical symmetry
and lead to a strong source of gravitational waves.
Prof. Brown works to develop analytical and
numerical tools that can be used to investigate these
strongly gravitating systems and predict the
gravitational radiation emitted by SNe and GRBs.
Prof. Lazzati studies the theory of long-duration
GRBs, believed to be produced by relativistic jets of
plasma ejected in the core of massive stars at the end
of their evolutionary cycle. He studies the
mechanisms for the energy release in the core of the
star, the physics of the jet propagation, the emission of
the prompt radiation, and the afterglow emission.
Prof. Blondin works with the CHIMERA
collaboration to develop full-physics threedimensional numerical simulations of core-collapse
supernovae. His particular interest is in understanding
the origin of the Spherical Accretion Shock
Instability, and its role in driving supernova
explosions. Prof. Fröhlich’s interests include the roles
of nuclear structure, the equation of state of bulk
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X-ray observations by Reynolds in the constellation
Sagittarius discovered the remains of the most recent
supernova in our galaxy
Supernova Remnants (SNRs) are a focus of
research at NCSU, from detection of scandium in
G1.9+0.3, the youngest supernova in our galaxy, to
the role of dynamical instabilities in disrupting the
oldest SNRs in our galaxy like the Cygnus Loop.
Profs. Borkowski and Reynolds use various spacebased observatories to study SNRs, in X-rays with the
Chandra, XMM-Newton, and Suzaku satellites, and in
infrared with NASA's Spitzer Space Telescope. X-ray
emission includes thermal emission, providing
information on remnant ages, energetics, and
www.physics.ncsu.edu
elemental composition; and nonthermal, synchrotron
emission from extremely energetic electrons, giving
information on the shock acceleration process which
is probably responsible for producing galactic cosmic
rays. Prof. Ellison studies the acceleration of these
particles via the Diffusive Shock Acceleration
mechanism including nonlinear effects of particle
acceleration on the shock dynamics. Prof. Blondin
uses hydrodynamic simulations to study the evolution
of SNRs, the role of instabilities in mixing heavyelement ejecta with circumstellar gas, and the
formation of large-scale asymmetries. Prof. Reynolds
models synchrotron emission at radio and X-ray
wavelengths from shell SNRs as well as from pulsarwind nebulae, "bubbles" of relativistic electrons and
magnetic field produced by pulsars. Both the spatial
distribution and the spectrum of this emission contain
information important for understanding how particles
are accelerated to high energies in astrophysical shock
waves, and how pulsars produce their relativistic
winds of material.
Cosmic Rays are the highest energy particles
observed from space. Prof. Ellison studies the
production of energetic particles in shock waves in a
variety of astrophysical sites via the Diffusive Shock
Acceleration mechanism. Shock acceleration is highly
efficient and nonlinear and most work involves
modeling this mechanism with computer simulations.
Cosmic rays affect nuclear abundances through a
process known as spallation, where a relativistic
proton can shatter a heavy nucleus such as oxygen to
produce lighter elements. Prof. Kneller aims to better
understand the sources of cosmic rays, their evolution,
and the environment where spallation occurs.
Dust is a primary source of infrared emission from a
variety of astrophysical objects. Astronomical dust is
one of the least understood components of the
interstellar medium. Profs. Borkowski and Reynolds
use infrared emission to infer the properties of dust in
SNRs and to understand grain destruction in hot,
shocked plasma. Prof. Lazzati’s research focuses on
the mechanisms of dust nucleation, the process of
forming the seeds of dust particles (usually micrograins with only several tens of atoms in them) from
purely gaseous compounds.
Computational Astrophysics is an over-arching
theme in the astrophysics group at NCSU. Prof.
Ellison uses Monte-Carlo techniques to model nonlinear effects in shock waves. Prof. Brown is
developing numerical algorithms for the Einstein
equations and using numerical simulations to model
gravitational wave production in binary black hole
systems. Profs. Fröhlich, Kneller and McLaughlin use
nuclear reaction network codes and neutrino transport
algorithms to study nucleosynthesis and neutrino
flavor mixing in a variety of astrophysics applications.
Profs. Blondin and Lazzati use large-scale 3D
hydrodynamic and magnetohydrodynamic simulations
to study systems ranging from stellar winds to GRBs.
Computing resources used by our group range from a
dedicated local linux cluster to national
supercomputers including DOE’s Jaguar at the
National Center for Computational Sciences, NASA’s
Pleiades and several NSF TeraGrid systems.
Further Information
We encourage interested applicants to learn more through the astrophysics group webpage, astro.physics.ncsu.edu.
Prospective students can contact the Graduate Program office at [email protected] or any faculty member
directly. The email addresses are as follows:
[email protected]
[email protected]
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www.physics.ncsu.edu