In the last several years, I have worked intensively on the supermassive star
Eta Carina, which in its great eruption 160 years ago, ejected an enormous mass
(10-20 times that of our sun) into space. In a short period of time,
astronomically speaking, the star itself may finally die in a supernova explosion.
The Hubble Space Telescope (HST) has designated our study of Eta Carina as one of
its Treasury Projects, devoting large amounts of time to studying its variations.
I'm enthralled by dirt -- at least the astronomical kind. The dust out of which
our planet formed, originally came from the stars. For many years, I have
been studying the conditions under which this dust condenses out of hotter gases.
Novae, for example, are stars that undergo non-fatal explosions that expel enormous
amounts of dust into space. I have played major roles in the decades-long
planning and development of the Spitzer Infrared Telescope, now bringing us
spectacular images of our dusty space environment. I am looking forward to using
the infrared-optimized LBT to study dust in interesting systems such as the RY
Scuti binary system, with two stars orbiting each other so closely that they touch.
My research spans the structure of our Milky Way to the study of the populations
of massive stars here and in nearby galaxies. I use our own in-house database
of a 100 million objects to map the structure of our galaxy and observations with
the Steward telescopes to study the "supernova imposters," which are very massive
stars expelling large amounts of matter into space.
I am an infrared astronomer who specializes in measuring the polarization of
light. This type of observation can reveal the structure of dust in comets,
the magnetic field geometry in galaxies and pinpoint the location of hidden
stars. Specialized observing procedures are required, but a few major
facilities such as the NASA IRTF and the Hubble Space Telescope have a
polarimetric capability I am able to use. We are building a precision infrared
imaging polarimeter for use on the MMT in combination with the AO secondary.
I do research in theoretical and computational astrophysics, mainly
addressing problems associated with very energetic phenomena and their
impact on the universe. My students and I carry out large fluid dynamical
simulations including specially developed routines to follow the microphysics
responsible for the emission we observe from such astronomical objects as
supernova remnants, active galaxies and clusters of galaxies.
Our calculations can be compared directly with observational data
to test basic theories about the origins of these objects.
I'm interested in the extremely high energy particles generated in shock waves,
both in giant clusters of galaxies on scales up to millions of light years, and
in the smaller explosions of dying stars, as they create supernova remnants. I
study these systems using radio, optical, X-ray and infrared images and spectra
from both ground- and space-based telescopes.
My research focuses on galaxy formation and evolution, using observations from both ground and space based facilities. My work covers all evolutionary stages of galaxies, from their infancy at the end of the dark ages, to their maturity in the local universe. This approach allows us to directly constrain what mechanisms are important in the galaxy formation process, and understand if their role changes with time.
Understanding how galaxies are formed and evolve presents arguably the biggest
challenge for astrophysics in the next decade. As new observing facilities
come on-line, we can look back to the earliest ages of our universe and
learn more about galaxies in their infancy. I am currently conducting a parallel
approach by studying the nearest dwarf galaxies which are the most numerous
galaxies in the Universe and the likely building blocks of all galaxies. Like
an archaeologist, I reconstruct their lives by exploring the
fossil records by measuring the ages, metallicities, and distributions of their
I am interested in the distribution of "dark matter" in the Universe, on scales
ranging from sub-galactic to those larger than clusters of galaxies. Dark matter
is the dominant matter component in the Universe, yet its nature has eluded us
so far. I study gravitational lensing of high redshift sources, and dynamics
of individual galaxies and clusters, to gain detailed knowledge of the clustering
properties of dark matter.
One focus of my current research is the study of solar system comets, which are
frozen reservoirs of primitive solar dust grains and ices. I analyze the
composition and size distribution of cometary dust grains from infrared imaging
and polarimetry techniques using the LBT and Steward Observatory telescopes which
support my Spitzer Infrared Telescope activities. In this way, I can determine the
physical characteristics of the solid materials that constituted the primitive solar
nebula, out of which planetesimals, then planets, and eventually we, ourselves,
Deep inside a star, the churning and the transfer of massive amounts of energy
are not open to direct observation. However, through the use of sophisticated
physical models and numerical simulations on supercomputers, we can investigate
how these invisible processes work. Recently, we have been concentrating on the
convection processes in stars near the end of their red giant phases.
Our observational colleagues can search for the subtle signatures of these processes,
and improve our understanding of the hidden interiors of stars.
I am a graduate student working with Dr. Claudia Scarlata on data from the WFC3 Infrared Spectoscopic Parallel (WISP) Survey. These data, from the Hubble Space Telescope, allow us to search for very high-redshift galaxies by detecting their emitted Lyman-\alpha. Our goal is to better constrain the bright end of the high-redshift ultraviolet luminosity function, which can tell us about the spatial density and evolution of galaxies at early times in the Universe.
I am currently collaborating with NASA/STScI on an infrared multi-object spectrograph to be installed at the MMT Observatory on Mount Hopkins. To manage the large amount of data from multi-object spectroscopy, I am also developing an automated data-reduction pipeline that can be generalized to LBT/MODS and MMT/Hectospec spectra. My science goals include identifying and studying Luminous Blue Variable (LBV) stars, rare and massive evolved objects that are characterized by dramatic changes in brightness.
In August 2011 I graduated with a Master's degree from Leiden University and am now working towards a Ph.D. here at the University of Minnesota. I am working with Dr. Scarlata on the relative escape fraction of ionizing photons from high redshift galaxies.
My research interests include studying the high-redshift Universe,
especially galaxy formation and evolution in the early Universe,
including galaxy dynamics and observational cosmology. My current
research looks to further our understanding of the formation and
evolution of galaxies at high redshift by studying their physical
characteristics and processes, using the data from various surveys such
as WISPS, UVUDF, and SPLASH.
My research with Dr. Scarlata seeks to further understand the central powering of Lyman-α nebulae. These so-called Lyman Alpha Blobs (LABs) are extended, luminous nebulae whose strong Lyα emission is not well understood. Answering this question is fundamental to our understanding of the nature and evolutionary status of these objects as well as their central galaxies. Scattering of Lyα photons by the neutral hydrogen can result in a net polarization in the Lyα emission. Furthermore, the resonant nature of Lyα allows the detection of associated stuctures near the emitting source. Thus spectro-polarimetry of the Lyα emission line provides a unique way to constrain the source of the emission as well as the kinematics and spatial structure of the surrounding regions.
I'm a big fan of numerical analysis and using computers as a tool for performing experiments. Computational simulation is pretty important for testing theory in astrophysics, since we can't exactly grow real stars and galaxies in a lab. As a graduate student, I am working under the supervision of Dr. Tom Jones investigating the formation of cosmic rays in supernova remnants. The expanding shock wave of a supernova explosion provides a peculiar environment in which charged particles can be accelerated to extreme energies through a process called diffusive shock acceleration. My work centers around simulations that investigate this complex interplay of microphysics which unfolds as such shock waves propagate through intersteller plasma.
My undergraduate years at Wesleyan University were spent on hunting for and studying AGN in nearby, low-luminosity galaxies with the help of the SDSS and our own spectroscopic data obtained from a number of major observatories. Recently, I've started working with Dr. Lucy Fortson on a sub-sample of blue elliptical and red spiral galaxies from the Galaxy Zoo project, with the purpose of characterizing nuclear activity, environment and star formation history.
I'm working with Shaul Hanany on EBEX, a balloon-borne CMB polarimeter that successfully completed its first data gathering flight in December 2012. Measurements of the CMB polarization anisotropy probe the inflationary epoch and improve constraints on several cosmological parameters. I'm working on new focal plane and lens designs that will increases EBEX's sensitivity in preparation for another flight in 2016.
I graduated with my Master's degree in Applied Physics in 2010 focusing on
laser spectroscopy and detonation fireball detection. I worked in the Air
Force Research Lab for 4 years researching novel fuel cell materials and
developing battery and fuel cell prototypes for portable power
applications. Here, I plan on pursuing studies in cosmology.
Specifically, I plan on researching dark matter distribution within
clusters of galaxies.