REU Projects for Summer 2009
at MIT Haystack Observatory
- The Super Massive Black Hole at the Galactic Center
- HI as a Tracer of Circumstellar Envelopes
- Pioneering Observations with the Murchison Widefield Array: Searching for Radio Transients *
- Pioneering Observations with the Murchison Widefield Array: Exploring the Sun *
- Development of an Optimized Antenna and Other Enhancements of a Spectrometer for the Study of Ozone in the Mesosphere
- Observing the Earth's Topside Ionosphere with Multiple Atmospheric Instruments
- Analysis of Ionospheric Storm Response Using Multi-Instrument Techniques
- Relationship between stratospheric and ionospheric disturbances
- Investigation of a Thermo-electrically Cooled UHF Radar Amplifier Module
*Part of a coordinated project. Please read
this for more information.
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The Super Massive Black Hole at the Galactic Center
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There is now a great deal of evidence that a 4 million solar mass black hole resides at the
center of the Milky Way Galaxy. Currently, the only way to spatially resolve structures within
a few Schwarzschild radii of the black hole is with high frequency very long baseline
interferometry (VLBI). This project will use models of SgrA*, the radio bright emission
associated with the Galactic Center, to explore the responses of both current and planned high
frequency arrays, with emphasis on how VLBI can be used to detect signatures of a true
gravitational singularity. In addition, by Spring '09, we should have new data on a 3-station
VLBI array that the participating student will be able to work on to put what they've learned
from models into practice. It is preferable that students have some programming experience.
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HI as a Tracer of Circumstellar Envelopes
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During the late stages of stellar evolution, stars with masses comparable to our Sun undergo
copious mass-loss, leading to the formation of extensive circumstellar envelopes ~1018
cm or more in diameter. These envelopes are a primary source of dust and heavy element
enrichment in the Galaxy, affect the structure of the interstellar medium on small scales,
and are precursors to the formation of planetary nebulae. Recent observations have shown that
neutral atomic hydrogen (HI) is common in circumstellar envelopes and can provide an
important new tracer of stellar mass-loss processes. In this project, the student will analyze HI
21-cm line observations of one or more mass-losing stars obtained with the Very Large Array
(VLA) and/or the Green Bank Telescope (GBT). Results will be compared with properties of
the circumstellar envelopes obtained from other tracers, such as dust, CO, and masers. Goals of
this study include obtaining new constraints on the duration of stellar mass-loss during the
asymptotic giant branch phase and exploring how evolved stars shape their interstellar
environments.
Applicants for this project should have some background in astronomy in addition to a solid
foundation in physics and mathematics. Familiarity with IDL and UNIX would be a plus.
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Artist's concept of MWA tiles
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Team project:
Pioneering Observations with the Murchison Widefield Array
Overview:
This project will be a team effort, divided into two sub-projects:
Description:
The Murchison Widefield Array (MWA)
is a revolutionary new low-frequency radio telescope under construction in the outback of
Western Australia. It will consist of 512 antenna "tiles", forming a high fidelity imaging
array in the 80-300 MHz frequency range. All the hardware for an engineering test bed
comprising 32 tiles is currently deployed at site and observations have recently commenced.
Students should indicate their interest in one or both of these sub-projects when submitting an application to this REU program.
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Pioneering Observations with the Murchison Widefield Array: Searching for Radio Transients
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This sub-project will be centered upon observations to detect
transient radio sources using the MWA in its 32 tile phase. The student will aid in completing
and testing pre-existant software, in order to detect small changes in the radio sky. This
software processing pipeline will then be applied to actual observations taken at the MWA in
Western Australia, in hopes that transient sources can be detected. If there are no detectable
transients, then the noise performance of the instrument will be characterized, and the
detection algorithms further improved, in order to facilitate subsequent detections.
A strong interest in physics and mathematics is helpful, as is experience in the C programming
language.
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Pioneering Observations with the Murchison Widefield Array: Exploring the Sun
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This sub-project will focus on studies of the Sun using the
data from the 32 tile prototype system. The wide variety of phenomenon which occur on the
sun make it a very interesting object for the MWA. It has complex emission structure and
variability spanning huge ranges in temporal and spectral scales. Also, we are currently slowly
emerging from the very bottom of the 11 year solar activity cycle, the longest and the deepest
minimum in about a hundred years. During such solar minimum conditions, the low frequency solar
observations can provide information on the unperturbed large scale electron temperature and
electron density in the solar corona. According to the current best predictions, the level of
solar activity is expected to increase significantly in 2009. The high frequency and time
resolution interferometric imaging capability of the MWA system will allow us to investigate
the nature and evolution of the solar bursts. Applicants with interest in learning data
processing techniques, software development, and possessing some curiosity about the Sun
are encouraged to apply for this position.
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Development of an Optimized Antenna and Other Enhancements of a Spectrometer for the Study of Ozone in the Mesosphere
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Haystack Observatory has developed a spectrometer to measure the ozone in the mesosphere
using inexpensive direct TV dishes with their satellite TV low noise block down converter
feeds (LNBFs) which operate in the 11 - 13 GHz band. Currently there are 2 11 GHz ozone
spectrometers running, one at Chelmsford High School and the other at Haystack Observatory.
The current design uses the satellite TV offset parabolic dish. The system temperature is about
100 K of which about 30-40 K comes from the ground pick-up from the spillover in the
illumination of the dish. While some preliminary work has been done looking at improvements
which result from using a dish with smaller f/D ratio and the addition of a ground screen to
reduce the spillover a more complete study is needed to optimize the design. In addition to
improving the current hardware design the project includes the further development of the web
based access to the data taken by the ozone spectrometers as well as development of online
analysis tools.
Students in EE with a background in hardware and software are encouraged to apply.
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Observing the Earth's Topside Ionosphere with Multiple Atmospheric Instruments
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The ionosphere is an important part of our solar-terrestrial environment. It is a region that
significantly influences radio wave propagation. It is characterized by free electrons and ions
produced by solar radiation. In this region, there is a substantial variation of electron density
with height from 100 km through 1000 km. This project is focused on the topside part of the
ionosphere above 500 km, an area that has not yet been fully characterized. Our primary
science objective is to obtain a better description of the topside. This project involves using
observations of total electron content (TEC) data obtained from multiple types of atmospheric
instrumentation, including GPS receivers, COSMIC satellites, and ionospheric radars, one of
the most powerful ground-based ionospheric sounding tools. A student involved in this project
will learn many aspects of upper atmospheric physics from observations, will be introduced to
different types of data processing, and will obtain a reasonable amount of computer experience.
We are looking for a student majoring in math or physics with a keen interest in learning about
space and atmospheric science. Computer experience in Matlab is desirable but not required.
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Analysis of Ionospheric Storm Response Using Multi-Instrument Techniques
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The charged portion of Earth's upper atmosphere, known as the ionosphere, undergoes dramatic
changes during periods of geomagnetic storm activity driven in the coupled Sun-Earth system.
In particular, ionospheric plasma often moves from low and mid latitudes to the edge of the
auroral oval. This takes the form of fast moving, greatly enhanced ionospheric density, with
significant consequences not only for upper atmospheric physics but for space weather disruptions
to communications and navigation systems. The nature of observed ionospheric storm disturbances
requires a multifaceted analysis approach to advance understanding of the globally coupled
mechanisms.
We seek a student to assist with observational data investigations focused on the mechanisms
and conditions under which these dramatic changes occur. The project will involve statistical
and event-based analysis of measurements from a variety of instruments. The primary
data analysis activities will use the MIT Haystack MADRIGAL database, (http://www.openmadrigal.org),
which contains large quantities of experimental ionospheric measurements. The student will focus
on combining distributed observations using ground-based (GPS total electron content, incoherent
scatter radar, HF radar backscatter network) and space based (DMSP satellite) instrumental
platforms. Data from experimental radar observations conducted specifically for this project
with the MIT Millstone Hill (Westford, MA), Poker Flat (Poker Flat, Alaska), and Resolute Bay
(Resolute Bay, Nunavut Territory, Canada) incoherent scatter radar systems will be a particular
focus. The project is most appropriate for undergraduates with an interest or desire to learn
about space physics and atmospheric science. Basic knowledge of statistics, data analysis,
and/or software development would be desirable, but are not a prerequisite. Activities will
involve data retrieval, scientific analysis, and visualization.
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Relationship between stratospheric and ionospheric disturbances
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Studies of ionospheric variability over many years have provided sufficient evidence that a
significant portion of day-to-day variations in ionospheric parameters is associated with lower
atmospheric state, but the processes and mechanisms responsible for such coupling are poorly
understood. Recent observational campaign arranged in January 2008 by the network of Incoherent
Scatter Radars presented solid experimental evidence that large variations in ionospheric and
thermospheric parameters are observed during a sudden stratospheric warming. Global simulation
models allow one to probe cause and effect of these processes in a way that is impossible to
approach observationally. This project will focus on analysis of TIMEGCM model output in order
to investigate how large changes in stratospheric dynamics are related to changes in thermosphere
and ionosphere.
This project is appropriate for a student with interest in space physics, meteorology, or
stratospheric dynamics. Some coursework in any of these fields is desirable, but not essential.
Experience with IDL and/or Matlab is helpful.
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Investigation of a Thermo-electrically Cooled UHF Radar Amplifier Module
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Incoherent Scatter Radar systems are among the most powerful of modern radars. They typically
operate in the UHF radio frequency range and are used to study the Earth's ionosphere and near
space environment. These multi-megawatt radar systems transmit and receive using large antennas
and require precision radio receivers to acquire their data. Recently we have been pursuing
investigation of upgrades to our radar front end system for use with the Millstone Hill Incoherent
Scatter radar. This radar system transmits with 2.5 million watts of peak power and uses two
antennas for its operations (a 46 meter steerable antenna and a 68 meter zenith-pointing dish).
For this project we will pursue the design, fabrication, and initial testing of a prototype
thermo-electrically cooled front end module for the radar system. This module will integrate
the low noise amplifier and noise injection components in a manner which can be cooled and
vacuum isolated. We will investigate the use of novel carbon nanotube materials with highly
anisotropic thermal conductivity for the module heat sinking and insulation. Simulations will
be used to help explore the potential of different heat sink materials and configurations with
the intent of optimizing the amplifier cooling and the resulting RF noise performance. We will
fabricate and test a laboratory prototype of this module to explore the device thermal and RF
performance experimentally. Testing will be done both using bench top test equipment and
potentially in the radar system itself if time allows.
This project is most appropriate for an electrical engineering or physics student with an interest
in radio receivers, radar systems, low noise electronics, or low temperature electronics design.
Some basic knowledge of electronics, thermodynamics, differential equations, and Matlab is needed.
Experience making measurements in a physics laboratory setting with National Instruments Labview
would also be useful.
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Final projects will be selected based on matching student applicant capabilities and interests with those of the sponsoring staff members.
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Application deadline: February 2, 2009
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781.981.5407 
