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- Joanna Levinne (UF) "A Determination
of Binary Frequencies in Young Embedded Clusters"
- Robert Hucksteadt (UF) "A Computational
Study of Interfacial Instabilities and their Role in Star
Formation"
- Janice Lomness(UCF) "Hydrogen Storage
in Quasicrystals of Totanium-Zirconium-Nickel and Titanium-Magnesium-Nickel
Alloys"
- James DeBuizer (UF) "Infrared Study
of Young Stellar Objects with Methanol Maser Emission: A
Search for Circumstellar Disks"
A
Determination of Binary Frequencies in Young Embedded Clusters
Joanna Levine
I propose to determine the frequency
of binary stars in a variety of young embedded clusters. This
study of binary fractions in young stellar clusters will have
important implications for a number of problems concerning
the required conditions for star formation. These include
determining whether (a) binary formation is a function of
environment and (b) most field stars form in clusters. In
addition, binary systems may affect the formation of planetary
systems. Relevant observations of the cluster NGC 2024 have
already been obtained in collaboration with Drs. Elizabeth
Lada and Richard Elston and we have developed the necessary
tools for data reduction and analysis. I will look at infrared
excess of the stars in our sample to determine whether circumstellar
or circumbinary disks are present. Ultimately, I will estimate
whether planets are able to form around binary systems and
place constraints on the conditions necessary for planet formation.
A
Computational Study of Interfacial Instabilities and Their
Role in Star Formation
Robert Hucksteadt
With the Origins Program, NASA is making
a bold effort to explore which lead to the creation of stars
and planets, and ultimately life. Star formation is an area
of research in which both observational and computational
studies are advancing rapidly. In my research I will utilize
state of the art computer codes to study nonlinear problems
for which analytical solutions can not be found. Interfacial
instabilities are a catalyst for star formation and large
structures in ISM. Understanding these instabilities will
increase our understanding of the origins of star clusters
and planetary systems. This is a worthy project for NASA,
and with NASA Space Grant support I will make a significant
contribution to astronomy in the fulfillment of my research
goals.
Infrared
Study of Young Stellar Objects with Methanol Maser Emission:
A Search for Circumstellar Disks
James DeBuizer
The association between interstellar
masers and the formation of massive stars has been known for
several decades. These masers are naturally occurring molecular
lasers that only exist under certain conditions and in very
confined regions (i.e. maser spots) near newly forming stars.
Therefore, they serve as powerful probes of small-scale structure,
dynamics and physical conditions of these environments. The
associated infant stars are known as "young stellar objects"
(YSOs), and it is their energy which is responsible for exciting
these masers which emit strongly at radio wavelenghts. While
increases in radio resolution have pinpointed the location
of the individual maser spots, details about their relationship
to the star-formation process remain unclear. In recent years,
methanol (CH3OH) masers have joined the extensively observed
H20 and OH masers as immensely valuable tools for studying
these regions near YSOs. Methanol masers, though frequently
correlated with OH masers, are suspected to originate within
disks of material surrounding these young stars. Radio results
obtained by Norris et al. (1993, ApJ, 412, 222) of more than
a dozen methanol maser groups (each group of maser spots being
associated with a single star) indicate a very strong preference
for individual methanol maser spots to be located along lines
or arcs. Norris suggests several hypotheses for the alignment
and concludes the most likely explanation is that the maser
spots are located in a circumstellar disk that is viewed nearly
edge-on.
While these masers emit strongly in at
radio wavelenghts, these YSOs cannot be viewed at visible
wavelengths because they are still heavily embedded in their
birth clouds, and therefore are totally obscured at the visible
wavelengths. Indeed, interpretation of maser data obtained
over the last twenty years has been limited by our inability
to locate the control stellar source. On the other hand, observations
in the infrared would allow one to peer into these clouds
and identify the young star associated with the maser. The
most complete survey of these regions at infrared wavelengths
was performed by the Infrared Astronomical Satellite (IRAS)in
the mid 1980s. Unfortunately, the small-scale spatial complexity
of the YSO environment made interpretation of data from this
survey difficult due to the satellite's relatively low resolution.
However, using large ground-based telescopes with mid-infrared
detectors will yield both the required resolution and the
ability to penetrate the significant obscuration in these
regions. This as yet unexplored application of the new generation
of mid-infrared array technology will allow identification
of the stellar source associated with the maser phenomena,
and yield an interpretation of the morphologies seen at other
wavelengths (e.g. radio).
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