REU program-Summer 2005
Univ. of Wisconsin - Madison
Madison, WI 53706
piadenz@gmail.com
My Summer 2004 Research Project
Research projects of other REU students
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REU program-Summer 2005 piadenz@gmail.com |
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My Summer 2004 Research Project Research projects of other REU students |
Scientists are still unsure of how massive stars form. It is believed that
they form in groups or clusters within very dense molecular clouds. They are
very bright and massive and as such, use their fuel in a relatively short time
as compared to their low mass counterparts. To understand how stars form we
must be able to look at them in their birth environments. For massive stars,
this means looking through highly extincted, very dense regions of dust and
gas. Therefore, infrared observations with surveys such as GLIMPSE are the key
to understanding high mass star formation.
Discovered by Rodgers,Campbell & Whiteoak (Rodgers et al. 1960) as part of a
H-alpha line emission survey, RCW 106 is a Giant H II (GHII) region in the southern
Galactic plane. Located 3.6 kpc away, RCW 106 is a large complex made up of
H II regions and molecular complexes that are, for the most part, invisible in
the optical part of the spectrum but spectacularly bright in the infrared. The
accompanying Giant Molecular Cloud (GMC) spans more than one degree of
the sky (between l=332.5 to 333.7). H20, Methanol and OH Maser sources have
been detected throughout RCW 106. Strong radio and x-ray sources are also
present throughout. Below is a brief history of surveys and studies that have
involved RCW 106.
1.2mm dust continuum: A recent 1.2 mm study of the GMC (Mookerjea et al.) revealed clumps of material which may be candidates for Ultra-Compact H II regions (UCH II) as well as clumps which may be sites for future massive star formation.
MSX: The Midcourse Space Experiment (MSX)detected many sources emitting in infrared wavelengths between 8 and 21 microns.
IRAS:The Infrared Astronomical Satellite (IRAS) performed an all sky survey at 12, 25, 60 and 100 microns and detected many sources in this region. One of them, IRAS 16183-4958, is one of the brightest infrared sources in the Galaxy (Becklin et al. 1973) and is associated with the well-known H II region G333.6-0.2.
FIR:
Far-infrared observations (150 and 210 microns) by Karnik et. al revealed at least 23 embedded sources detected at 210 microns which indicates that high mass star formation is ongoing in this region.2MASS: The Two Micron All Sky Survey (2MASS) mapped this region in bands J (1.25 microns), H (1.65 microns) & K (2.17 microns). Although massive protostars are generally too embedded to be seen in the K band, 2MASS measurements do reveal some regions which are too extincted to be seen in visible wavelengths.
Maser Surveys:
Several maser surveys, most notably those performed by Caswell et al. (1987) have revealed masers throughout this region. Since masers only exist in very dense regions with strong sources of excitation, they are excellent tracers of massive star formation.
Since RCW 106 has been observed in a very broad range of wavelengths, GLIMPSE data can be used to complete the spectral energy distributions of sources in this complex thus leading to the identification and classification of massive protostars in their birth environments. I am measuring the fluxes of selected sources in RCW 106 in order to get the luminosities in GLIMPSE bands ([3.6],[4.5],[5.8],[8.0] microns). I will use all of this information to characterize and model star formation in RCW 106.
I am also incorporating research from last summer . Dr. Whitney and collaborators are developing a larger, more comprehensive model grid and fitter that will aid in identifying and classifying protostars in this region. The results of the model fitter when applied to RCW 106 as well as complete SEDs of selected individual sources and clumps will be published.