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MASS-LOSING EVOLVED STARS AND IN PARTICULAR ASYMPTOTIC GIANT BRANCH (AGB) STARS AND RED SUPERGIANT (RSG) STARS ARE EXPECTED TO BE THE MAJOR PRODUCERS OF DUST IN GALAXIES. THIS DUST WILL HELP FORM PLANETARY SYSTEMS AROUND FUTURE GENERATIONS OF STARS. OUR ADAP PROGRAM TO MEASURE THE MASS LOSS FROM THE AGB AND RSG STARS IN THE MAGELLANIC CLOUDS IS NEARING COMPLETION AND WE WISH TO EXTEND THIS SUCCESSFUL STUDY TO THE GALACTIC BULGE OF THE MILKY WAY GALAXY. METALLICITY SHOULD DETERMINE THE AMOUNT OF ELEMENTS AVAILABLE TO CONDENSE DUST IN THE STAR'S OUTFLOW SO EVOLVED STARS OF DIFFERING METALLICITIES SHOULD HAVE DIFFERING MASS-LOSS RATES. BUILDING UPON OUR WORK ON EVOLVED STARS IN THE MAGELLANIC CLOUDS WE WILL COMPARE THE MASS-LOSS RATES FROM AGB AND RSG STARS IN THE OLDER AND POTENTIALLY MORE METAL-RICH BULGE TO THE MASS-LOSS RATES OF AGB AND RSG STARS IN THE MAGELLANIC CLOUDS WHICH HAVE LOWER METALLICITY MAKING FOR AN INTERESTING CONTRAST. IN ADDITION THE GALACTIC BULGE LIKE THE CLOUDS IS LOCATED AT A WELLDETERMINED DISTANCE (~8 KPC) THEREBY REMOVING THE DISTANCE AMBIGUITIES THAT PRESENT A MAJOR UNCERTAINTY IN DETERMINING MASS-LOSS RATES AND LUMINOSITIES FOR EVOLVED STARS. TO MODEL PHOTOMETRIC OBSERVATIONS OF OUTFLOWING DUST SHELLS AROUND EVOLVED STARS WE HAVE CONSTRUCTED THE GRID OF RED SUPERGIANT AND ASYMPTOTIC GIANT BRANCH MODELS (GRAMS; SARGENT ET AL 2011; SRINIVASAN ET AL 2011) USING THE RADIATIVE TRANSFER CODE 2DUST (UETA AND MEIXNER 2003). OUR STUDY WILL APPLY THESE MODELS TO THE LARGE PHOTOMETRIC DATABASE OF SOURCES IDENTIFIED IN THE SPITZER SPACE TELESCOPE GLIMPSE SURVEY OF THE MILKY WAY AND ALSO TO THE VARIOUS INFRARED SPECTRA OF BULGE AGB AND RSG STARS FROM SPITZER ISO ETC. WE HAVE ALREADY MODELED A FEW GALACTIC BULGE EVOLVED STARS WITH GRAMS AND WE WILL USE THESE RESULTS AS THE FOUNDATION FOR MODELING A LARGE AND REPRESENTATIVE SAMPLE OF GALACTIC BULGE EVOLVED STARS IDENTIFIED AND MEASURED PHOTOMETRICALLY BY GLIMPSE. WE WILL USE OUR GRAMS GRID EXPANDING AS NECESSARY TO ENABLE MODELING OF THE HIGHER METALLICITY EVOLVED STARS OF THE GALACTIC BULGE ALONG WITH MODELS OF OTHER TYPES OF STARS SUCH AS YSOS (ROBITAILLE ET AL 2006) TO IDENTIFY THE EVOLVED STARS IN THE GLIMPSE SAMPLE OF THE GALACTIC BULGE. WE WILL USE THESE WELL-TESTED GRAMS MODELS WHICH WE HAVE ALREADY EXTENSIVELY APPLIED TO STUDY POPULATIONS OF MASS LOSING EVOLVED STARS IN THE MAGELLANIC CLOUDS TO FIT THE SPECTRAL ENERGY DISTRIBUTIONS (SEDS; PLOTS OF EMITTED POWER VERSUS WAVELENGTH) OF GLIMPSE GALACTIC BULGE SOURCES IDENTIFIED AS RSG STARS AND OXYGEN-RICH (O-RICH) CARBON-RICH (C-RICH) AND EXTREME AGB STARS. THIS MODELING WILL YIELD STELLAR LUMINOSITIES AND MASS-LOSS RATES AS WELL AS GENERAL DUST CHEMISTRY (O-RICH VERSUS C-RICH) AND OTHER ESSENTIAL CHARACTERISTICS OF THE DUST PRODUCED BY EVOLVED STARS IN THE GALACTIC PLANE. OUR ONGOING MAGELLANIC CLOUD AND PROPOSED MILKY WAY GALACTIC BULGE EVOLVED STAR STUDIES WILL LAY THE GROUNDWORK FOR FUTURE STUDIES OF EVOLVED STARS IN OTHER NEARBY GALAXIES USING DATA FROM THE JAMES WEBB SPACE TELESCOPE AND OTHER PLANNED MISSIONS.

$106,206FY2020National Aeronautics and Space AdministrationNASA

Association Of Universities For Research In Astronomy, Inc., Tucson AZ

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