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------- Advisor's project abstract.
One way to identify active star formation is to search for molecular
outflows, because they have been observed toward protostars in high
frequency. Outflows are an important source of turbulence in star-forming
molecular clouds, and they inject significant amounts of energy into the
surrounding medium.
The COMPLETE Survey of Star-Forming Regions (cfa-www.harvard.edu/COMPLETE)
will provide the perfect database for an outflow search. COMPLETE is
comprised of COordinated Molecular Probe Line Extinction and Thermal
Emission observations of three large star-forming regions
scheduled to be extensively observed by SIRTF. What is unique about
COMPLETE is its coordinated approach. Prior observations of the types
Included in COMPLETE abound, but they only rarely fully-sample any region,
and no survey has ever covered a single (~10 pc) region fully with molecular
line, extinction, and dust emission observations. The lack of an unbiased
survey like COMPLETE has left star formation theories without statistical
constraints on the temporal and spatial frequency of: inward motions,
outflow motions, star formation; cloud disruption; core formation and
several other key parameters.
Using the COMPLETE molecular line maps taken at FCRAO, a summer
intern should be able to search for molecular outflows and make an
important contribution to the field of star formation.
1) Cassandra Fallscheer's project abstract
PROJECT TITLE: Young stellar outflows
ADVISOR: Alyssa Goodman
INTERN: Cassandra Fallscheer
------- PROJECT TITLE: A COMPLETE Search for Young Stellar Outflows
------- Advisor's project abstract: 2) Wesley Fraser's project abstract
PROJECT TITLE: Outerplanet satellites
ADVISOR: Matt Holman
INTERN: Wesley Fraser
------- The Chandra Multiwavelength Project (ChaMP) is sensitive to distant
galaxy clusters from two perspectives - X-ray and optical. The ChaMP
is detecting extended X-ray sources, both by eye and with our
automated detection algorithm. While we find classic clusters with
X-ray extent and multiple optical galaxy candidate members over a wide
range of redshift, some of the extended X-ray sources are associated
with single optical sources. In deep optical images, the ChaMP is
discovering galaxy over-densities associated with X-ray sources. Some
of these are X-ray point sources such as quasars while others are
extended X-ray sources. The ChaMP, with its wide area and faint flux
limits provides the potential for significantly expanding the
luminosity/redshift coverage of the known cluster population,
key both to understanding the evolution of clusters and to
constraining cosmological parameters. Already, as described above, the
variety of cluster-like objects being found surpasses that of previous
X-ray or optical surveys. The goal of this project is to compare the
deep X-ray and optical images to find clusters of all types and to
characterize their X-ray and optical properties, and compare with
previously known clusters in a short paper. Calibrated X-ray and
optical imaging data are in hand and optical spectroscopy is available
for a subset of the candidate sources. Even for sources without
spectroscopy, our existing three-filter optical photometry can be used
to estimate the redshift of the cluster from its red galaxy color
sequence. A well-established red-sequence also constrains the age of
the cluster elliptical galaxy population. Finally, we will combine
our new clusters with those from previous samples to test for a
proposed relation between the optical galaxy richness of clusters and
their X-ray luminosity across an extended range of cluster properties.
------- Advisor's project abstract:
We have a program (partially supported by an NSF grant) to test a
concept for achieving the very high dynamic range required
for detection of reflected light from exo-planets. We will use an
Apodized Square Aperture (ASA) (Nisenson and Papaliolios, 2001) to
control the telescope diffraction. ASA adjusts the transmission of
the telescope pupil and dramatically reduces diffraction by the
telescope except along two narrow crossed, on-axis strips,
perpendicular to the edges of the aperture. ASA was originally
conceived to be used, in the visible, in NASA's Terrestrial Planet
Finder mission as an alternative to an infrared interferometer for
finding and characterizing terrestrial-sized extra-solar planets. In
this program, ASA could also be used, when combined
with adaptive optics and speckle techniques, to detect the light from
optimally placed giant planets (orbits known from radial
velocity measurements) orbiting nearby stars.
We are currently setting up to perform lab simulations that allow
us to test our cameras, apodizing technique, and data analysis
algorithms. A summer intern could help us take test data, help
develop the software for data analysis (using IDL), analyze the
simulation data, and even help us write a paper on the results.
This will prepare us for observing runs using these techniques
that will start next fall.
3) Joleen Miller's project abstract
PROJECT TITLE: Extrasolar planets
ADVISOR: Pete Nisenson
INTERN: Joleen Miller
------- Direct imaging of extra-solar planets or planetary systems would
provide coarse photometric and spectroscopic information, giving
insights into the planet's atmospheric composition. It would also give
an unambiguous determination of the planet's mass (if combined with
radial velocity data) by eliminating the ambiguity in the orbital
inclination. Direct imaging is extremely difficult due to the large
dynamic range required to separate the light from the central star
from the light reflected by the nearby planet. Both the diffraction
from the telescope aperture and scattered light need to be controlled
with extreme precision for planet imaging.
------- Advisor's project abstract:
4) Michael Mortonson's project abstract
PROJECT TITLE: X-ray detector development
ADVISOR: Eric Silver
INTERN: Michael Mortonson
------- I am interested in offering a summer project to an intern interested in
experimental physics. The intern will learn about low temperature physics and
cryogenic techniques applicable to the development of high resolution x-ray
detectors. This may include traveling to the National Institute of Standards
and Technology (NIST) to participate in laboratory astrophyiscs measurements
on an Electron beam Ion Trap. I will have a better idea of the exact project
once I meet with the student.
------- Advisor's project abstract:
At present, no members later than about F5 in spectral type are
currently known for either cluster. With ages of about 25 Myr and
at a distance of just 320 to 360 parsecs, the late-type memberships
of the NGC 2232 and Cr 140 clusters will yield an almost unique sample
of solar-type stars in the post-T Tauri/pre-main sequence phase of
evolution.
The data generated by this project will be used to bolster the
late-type membership of these clusters (crucial for the study of
the evolution of magnetic dynamo activity in young solar-type stars)
as well to re-assess the likely ages and distances of these clusters.
5) Chris Orban's project abstract
PROJECT TITLE: X-ray stars in open clusters
ADVISOR: Brian Patten
INTERN: Chris Orban
------- For this project, X-ray sources will be identified and net source
counts will be extracted in eight ROSAT HRI images in the regions of
the NGC 2232 and Cr 140 open clusters. These X-ray data will be
combined with ground-based photometry and spectroscopy in order to
identify candidate G, K, and early-M type members of these clusters.
------- Advisor's project abstract: 6) Nada Petrovic's project abstract
PROJECT TITLE: Microlensing
ADVISOR: Rosanne DiStefano
INTERN: Nada Petrovic
------- Microlensing is an exciting tool to probe for
dark matter, to study binary stars, and, potentially,
to discover distant planets. The project we would
work on this summer would have 2 possible components:
(1) comparing different microlensing techniques to discover
planets, and (2) to study the influences that source and
lens binarity have on estimates of the optical depth. The
optical depth is a measure of the amount of dark matter that
may be in the form of compact massive halo objects (MACHOs).
------- Advisor's project abstract: 7) Dan Perley's project abstract
PROJECT TITLE: Search for galaxy clusters
ADVISOR: Paul Green
INTERN: Dan Perley
------- Text of originally proposed project is not available.
------- Advisor's project abstract: 8) Caroline Ring's project abstract
PROJECT TITLE: Infrared star forming regions
ADVISOR: Lori Allen, et al.
INTERN: Caroline Ring
------- This August the NASA SIRTF telescope system is due to launch,
and it is expected to discover thousands of very young stars in the
nearest star-forming complexes by observing at mid-infrared
wavelengths. To prepare for our group's observing programs with this
telescope, we want to assemble complementary near-infrared
observations of our target regions, made in the last several years
with the ground-based 2MASS telescope. These data have just been
released, and are easily accessible over the internet. This program
is an opportunity for a student to make a comprehensive study of the
stellar content of nearby star-forming regions, and to learn useful
techniques of data analysis.
------- Advisor's project abstract:
A student who will work on this project will learn how to analyze
X-ray and optical data using existing and previously tested software
(CIAO, Sherpa, IRAF). There are ready made scripts and tasks to do
parts of this analysis which will be used by the student (after of
course the required training). They will also be exposed to the
interpretation of scientific data and learn about the different types
of sources in galaxies and how we can distinguish between them using
observations in different wavebands (mainly optical and X-rays). This
way they will learn about the current views of the connections between
galactic X-ray source populations and stellar populations. Finally
they will learn how to do background literature research on a specific topic.
9) Paul Taylor's project abstract
PROJECT TITLE: Small Magellanic Cloud
ADVISOR: Andreas Zezas
INTERN: Paul Taylor
------- With Chandra we can obtain very sharp images of other galaxies. This
allows us to probe their X-ray source populations to much fainter
limits than was possible before. We chose to observe one of our nearest
star-forming galaxies, the Small Magellanic Cloud, in order to study
its low luminosity X-ray sources. The main aim of this project is to
detect the discrete sources in the five fields of our SMC survey and
perform a preliminary study of their X-ray properties (hardness ratios
and possibly variability by comparison with earlier ROSAT and Einstein
source lists). In a later stage these results will be used to produce
an X-ray luminosity function of these sources. Comparison with
results from other galaxies studied at this depth (eg Milky Way, M33,
M31) as well as with other more distant galaxies will be used to
understand the relation between star-formation activity and X-ray
source populations. The SMC has been extensively observed in the
optical so we will be able to identify optical counterparts of the
X-ray sources by cross-correlating them with lists of optical sources.
------- Advisor's project abstract: 10) Deborah Turner-Bey's project abstract
PROJECT TITLE: Magnetism in A-type Stars
ADVISOR: Vinay Kashyap
INTERN: Deborah Turner-Bey
------- To explore the limits of magnetic dynamo
activity on stars at the high-mass end of the the main sequence.
The magnetic dynamo begins to operate for late A type stars and
is the cause of coronal X-ray emission. No early type A stars
have been detected in X-rays, and the location of the boundary
where magnetic activity (and hence coronal X-ray emission) turns
on has been an open question for decades. Observations with
Chandra provide a means to attack this problem. Starting from
optical catalogs of bright blue stars and then searching through
the ChaMP database to determine whether these stars have been
detected or whether upper limits must be set on the flux, we
can study the onset of magnetic activity and coronal emission
on normal stars.
------- Advisor's project abstract: 11) Katherine Whitaker's project abstract
PROJECT TITLE: X-rays from Cluster Abell 119
ADVISOR: Ralph Kraft
INTERN: Katherine Whitaker
------- We will study the X-ray emission from the nearby (z=0.0442) cluster
of galaxies Abell 119 using archival XMM-Newton data.
Previous optical and X-ray observations suggest that this cluster is
undergoing a minor merger. We will use the X-ray data to
determine the temperature, the pressure, and the elemental abundances
of the gas. From this we will be able to compute the total
gravitating mass (i.e. dark matter) in the cluster.
We will also create a temperature map to search for
evidence of structures related to the merger.
Such phenomena include 'cold-fronts', possible 'abundance-fronts', and shocks.
The scientific goal of this project is to better understand the
hydrodynamics of cluster mergers and the formation of structure.
1) Cassandra Fallscheer
CalPoly/San Luis Obispo
Abstract:
The study of molecular outflows is very important in the quest for
understanding the process of star formation. Using data collected in
the Coordinated Molecular Probe Line Extinction Thermal Emission
(COMPLETE) Survey, a list of known molecular outflows in the Perseus
Cloud Complex was compiled. A process was developed to search the
COMPLETE data for new candidates of molecular outflows.
--- Advisor: Alyssa Goodman
Preliminary abstract:
Abstract from final paper:
In this paper we discuss a new technique of finding moving objects in
a series of images. this technique implements a 'shift and add'
method of stacking images, and allows a deeper probing than the
standard three image detection routine. We describe the results of
using this technique on an ecliptic Kuiper belt survey. We use this
and three other ecliptic surveys to analyze the possibility of
different size distributions for the high and low inclination objects.
We find it highly likely (99%) that there is only one size
distribution between the two groups.
During the time I am at the Smithsonian Astrophysical Observatory,
working with Dr. Matthew Holman, I will be contributing to at least
two research projects. The first will be data acquistion at Cerro
Tololo Inter-American Observatory, followed by data reduction and
search which is expected to lead to the discovery of new Neptunian
satellites. This is a continuation of the work I did during the
summer of 2002.
In addition, I will be involved in a Kuiper Belt survey, using the
same data sets. MyRingprinicipal responsibility for this project will be
to optimize the automated search software that will be used.
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Pencil Beam Search Technique and the Size Inclination Distribution of the Kuiper Belt
--- Advisor: Matt Holman
Abstract:
We present the results of our efforts to develop a procedure to
determine the velocity shifts between the stellar reference spectra
before and after the upgrade of the Advanced Fiber Optic Echelle
(AFOE). When the AFOE spectrograph was upgraded to increase its
ability to measure radial velocity variations, the change necessitated
taking new stellar references for each star system. All velocity
measurements for a given star are made relative to this reference,
which is simply an observation of the star on a particular night.
However, there is an unknown velocity shift between every pair of new
and old stellar reference spectra simply because they were observed on
different nights. In addition, other intrinsic differences between
the two spectra prevent us from simply recalculating all of the
velocities relative to one reference or the other. To overcome this
problem, we have begun developing a procedure that calculates the
velocity shift between a pair of new and old stellar references. We
perform the calculation independently for each wavelength range of the
new spectrum that overlaps the old spectrum, which gives us twelve
measurements of the velocity. The spread in our results gives us an
idea of the precision of our calculations, and we hope to be able to
measure the velocity shift with a precision of ~ 1m/s. In this paper
we explain our procedures in more detail and discuss our progress of
calculating the velocity shift for the star beta Aquilae.
Calculating Velocity Shifts Between the Pre- and Post-Upgrade AFOE Data Sets
--- Advisor: Pete Nisenson
Abstract:
We have completed a new X-ray microcalorimeter system to detect X-rays
from plasmas produced by an Electron Beam Ion Trap at the National
Institute of Standards of Technology. the instrument is an upgrade to
a detector that was previously used for laboratory astrophysics; it
has a 1x4 array of microcalorimeter detectors and improved cooling and
data acquisition capabilities. During the test run of the new
instrument, spectra of highly charged ions of neon, argon, and krypton
were obtained and calibrated using observations of X-rays from a
calibration target. We report on the data and the performance of the
instrument, noting its advantages over the previous detector as well
as a few new technical problems that must me addressed.
Commissioning a New X-ray Microcalorimeter for Laboratory Astrophysics
--- Advisor: Eric Silver
Abstract:
NGC 2232 is one of the nearest open clusters (~360 pc) with an age of
~25 Myr. This places it in the unique position to study the
transition from T Tauri activity to the Zero Age Main Sequence. In
order for those studies to begin, late-type members must be identified
for the clusters. X-ray observations combined with ground-based
photometry and spectroscopy offers the best way to accomplish this
goal. We present photometry in the VRI bands, 2Mass near-infrared
measurements in the J, H, K bands and spectra for the suspected
optical counterparts to the X-ray sources in the field of NGC 2232.
46 late-type members were identified through these efforts.
Late-type Membership in the Open Cluster NGC 2232
--- Advisor: Brian Patten
Abstract:
Microlensing is a fascinating phenomenon which both provides a
confirmation of the General Theory of relativity as well as yields
information about the portions of our galaxy that we cannot see, such
as dark matter. early microlensing observational searches located
strong candidates of point lens, point source light curves as well as
binary source and binary lens light curves. However, very few mildly
perturbed light curves were observed, which a problematic omission.
Also, Di Stefano has suggested that the failure to take binary effects
into account may have influence`d the estimates of optical depth
derived from microlensing surveys. This paper is a first step in a
systematic analysis of binary lenses and binary sources and their
impact on statistical microlensing surveys. In order to begin
assessing this problem, we ran large-scale Monte Carlo simulations of
various microlensing events involving binary stars (both as the source
and as the lens) in order to study the lensing and perturbation rates.
The five situations we focussed on were a point lens/point source
case, the point lens/binary source without binary motion, point
lens/binary source with binary motion, binary lens/point source, and a
binary lens/binary source including binary motion. For each lensing
event we recorded the parameters of the system as well as the times
where the curve reached 1.34 magnification. We also sampled the
characteristic light curve and recorded the chisq value of a point lens
fit to this light curve as will as the maximum magnification.
Finally, we recorded the numbers of repeating events, or events which
temporarily dipped below the 1.34 magnification value. Using the
recorded parameters for each system we were able to reconstruct our
sampling range for each individual value of closest approach in order
to directly compare the lensing rates in all five of the cases. We
found that the binary source light curves had a lensing rate
approximately 1.04 times the rate of the point source/point lens light
curves. On the other hand, the binary lens light curves had a rate of
approximately 1.4 times the rate of the point lens/point source case.
Using the chisq values for the fits, and defining a chisq of greater
than 1.5 to be perturbed, we found the perturbation rate of binary
source light curves to be approximately 5-6% and the perturbation rate
due to binary lenses to be approximately 32% which increased to 35%
with addition of a binary source to the binary lens. We found
significant rates of repeating events in all cases but the point
source/point lens. The point lens/binary source with motion, and the
binary source/binary lens case had significant fractions of repeating
events with more than one repeat, while the binary lens point source
and the binary source with no motion mainly caused events with one
repeat. We used the starting and ending times of the curves to
determine the duration rates of the various lensing events. We noted
that the durations were slightly different for each of the five
simulations, and that the binary lens cases tended to have a larger
fraction of short duration events. Finally, we used the maximum
values of the sampled curves to calculate the distance of closest
approach as it would be calculated by observers, noting that in the
binary lens case an artificially high number of events appeared to
have small distances of closest approach due to the high
magnifications caused by caustic crossings.
The Role of Binary Sources and Binary Lenses in Microlensing Surveys
of MACHOS
--- Advisor: Rosanne DiStefano
Abstract:
In this project, we search for serendipitous X-ray clusters,
investigate their properties and assess their detectability in optical
surveys. Using automatic and manual methods, we search 62 Chandra
observations retrieved from archival data in ChaMP, the Chandra
Multiwavelength Project, for extended sources. We use visual
inspection and red_sequence analysis to evaluate these sources,
isolating possible new clusters from spurious detections and
non-cluster sources. In addition to detecting five previously known
sources, we find two new probable clusters and one additional cluster
candidate. Cluster detections are analyzed to estimate redshifts,
X-ray luminosities, and other information. We also investigate the
Voronoi Tessellation and Percolation (VTP) algorithm in combination
with red sequence-based color filtration as a potential cluster
finding tool. In preliminary tests, we find that filtered VTP
successfully detects all seven (primarily optically faint) clusters in
the sample to which it is applied, but a large number of apparently
spurious sources are also detected that would have to be screened out
via color-magnitude analysis or another confirmatory method. Early
results are very encouraging, but further investigation will be needed
to establish the practical effectiveness of the algorithm in optical
cluster detection.
Explorations in Multiwavelength Cluster Detection Using Chandra
--- Advisor: Paul Green
Abstract:
The SIRTF Legacy Cores-to-Disks (c2d) program has compiled a database
of molecular cloud cores planned for observations using SIRTF. Cores
in the c2d sample have not been examined for star formation using a
uniform database since IRAS (launched 1983). We use the 2MASS
database to examine the c2d sample of molecular cloud cores which have
been classified as "starless" for infrared excess sources, which, if
found, would imply that their classification whould be changed. (J-H)
- (H-K) color-color diagrams are used to identify sources with
infrared (IR) excess. IR excess sources whose projected position lie
within the boundaries of the molecular cloud cores are examined
further, using spectral energy distributions, in an attempt to
classify them.
An Examination of Starless Molecular Cloud Cores in SIRTF
Core-to-Disks Sample
--- Advisor: Lori Allen et al.
Abstract:
We present the results of a survey of the central part of the Small
Magellanic Cloud Galaxy by the Chandra X-ray Observatory. The field
of view covered an area of 1280 square arcmin along the most active
region of the SMC with five observations between May and October, 2002.
This survey was performed with ACIS (Advanced CCD Imaging
Spectrometer) in an energy range 05.-0.7 keV. Sources were detected
using the wavdetect algorithm, and then spectral and timing analyses
were performed on bright detections. the survey yielded a total of
122 significant sources (at 3 sigma level) down a flux near 1e-14
erg/sec/cm2 in the full band (0.7-1.0 keV) and near 1e-15 erg/s/cm2
for the soft band (0.1-2 keV). Among these sources we identify two
supernova remnants, seven known X-ray binaries, and eight sources
which are most likely pulsar binaries, based on spectra and
variability from the Chandra data. Log(N)-Log(S) relations were used
to compute the number of detected sources not associated with the SMC
region, and that value was found to be at most 155 sources, with a
minimum of ~50 sources. Comparisons were made with previous X-ray and
optical surveys for identification of sources, namely the ROSAT PSPS
and HRI, ASCA, and UBVR surveys, and then cross-correlated with the
SIMBAD database. In all, 18 ASCA sources, 26 PSPC, 15 HRI and 38 UBVR
were associated with Chandra sources. Due to the high density of
optical sources, the probability of chance overlap was calculated and
found to be ~30 sources.
A Chandra Survey of the Bar Region in the Small Magellanic Cloud
--- Advisor: Andreas Zezas
Abstract:
A solar type magnetic dynamo is believed to come into operation in
late-A stars. Because coronal activity is strongly dependent on the
presence of a magnetic dynamo, X-ray emission is a tracer of this
dynamo. We have carried out a systematic search for A type stars in
Chandra observations using the database of serendipitous detections
derived from the Chandra Multi-wavelength Project (ChaMP). No X-ray
emission has been conclusively detected in early-A stars, and the
ChaMP database provides a significant opportunity to constrain the
onset of the dynamo in main sequence stars. In this preliminary
survey, we have identified numerous X-ray sources as A star
candidates, and find that the data are consistent with main sequence
stars becoming X-ray emitters at V-R ~ 0.15, between A6 and A9.
The Onset of Magnetic Dynamo Activity in A-Type Stars
--- Advisor: Vinay Kashyap
Abstract:
We have analyzed archival XMM-Newton data of the nearby cluster of
galaxies Abell 119 (A119), studying the X-ray emission from the
intracluster medium. Using the beta model, derive the luminosity to
be 1.64e+44 ergs/s at a radius of 0.73 Mpc, with a central density of
1.63e-3g/cm3. The total gravitating mass within a radius of 0.73 Mpc
is 3.76e+15 solar masses, with a plasma mass of 3.11e+14 solar masses,
giving a ratio on 8.3%. We measure the average temperature of A119 to
be 5.99 keV. A temperature map and azimuthally symmetric profile with
the beta model has a minor merger in the northeast region, believed to
be falling in at a temperature of 4.41+/-0.44 keV along one of three
filaments in the cluster.
An XMM-Newton Study of the X-ray Emission from Abell 119
--- Advisor: Ralph Kraft