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Graduate Student Research Forum: Project abstract for potential grad student project.
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Star formation in the Cygnus-X Spitzer Legacy Survey
Abstract:
The Cygnus-X region contains a massive star formation complex with the
richest known concentration of massive protostars and the largest OB
associations in the nearest 2 kpc. This unbiased survey of 24 sq degrees in
Cygnus-X with the IRAC and MIPS instruments will have the sensitivity to
detect young stars to a limit of 0.5 Msolar. The Cygnus-X survey will be an
important step in constructing one of Spitzer's greatest legacies:
surveying with high sensitivity and spatial resolution a representative
sample of Galactic star forming regions, from Bok globules to complexes
containing millions of solar masses of gas and hundreds of O-stars. See
the project web page at http://www.cfa.harvard.edu/cygnusX for more
information. We currently have the full MIPS data set and the remainder of
the IRAC data were taken a couple weeks ago. A first pass at the data
reduction has been performed, producing images and source catalogs. We
have optical r', i', and Halpha photometry from the IPHAS survey for the
region, and deeper JHKs photometry in the DR21 region and on S106.
Project A: Characterizing the Infrared Dark Clouds in the Cygnus-X Spitzer
Legacy Survey
One project will focus on the infrared dark clouds (IRDCs) in the survey
region. These regions of high extinction have been found to be correlated
with molecular clouds and often contain objects at the earliest stages of
star formation. Until now the IRDCs have been studied using MSX and
recently the IRAC GLIMPSE data toward the inner part of the Galaxy; the
greater sensitivity of the Cygnus-X dataset will allow us to better
distinguish these objects from the background and characterize them in
detail. The project will begin with a census of the IRDCs in the survey
region, and a search for protostars and associated low-mass star formation.
The properties of the IRDCs including densities, masses, and sizes will be
determined. There are often clusters of low-mass stars associated with the
dark clouds, which will also be characterized using the Spitzer data. The
analysis will make use of the Spitzer Legacy survey as well as other
existing datasets - optical, near-IR, sub-mm, and mm data.
Project B: Star formation in the DR21 Region
The Legacy survey includes the DR21/W75 star formation region, which are
bright IR sources that are associated with massive, dense cores that are
currently forming stars. Both sources are associated with UCHII regions,
masers, and massive bipolar outflows. The sources are located along a
ridge of dense material that extends over a degree in size on the sky. The
project would consist of an in-depth study of the star formation in this
region, finding and characterizing clusters in the region, and determining
the star formation history and the interaction between the massive star
formation and low-mass stars. Many of the necessary techniques for
analyzing the data have been developed and used previously by students L.
Chavarria and X. Koenig in their work on other massive star formation
regions (S255 and W5); the methods would be applied to the Cygnus-X
dataset. We have also begun a program of optical spectroscopy using the
FAST instrument to find the O and B star population in the DR21 region, and
to characterize a sample of Class II stars found using the IRAC photometry.
This will allow us to find the ionizing sources, and to better understand
the star formation history of the region. The optical data will be
obtained this fall.
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