Dr. Masaaki OTSUKA (ASIAA, Taiwan)
Dust Production in Planetary Nebulae
Planetary Nebulae (PNe) represent a final stage in the evolution of low- to intermediate-mass stars with initially 1-8 solar mass; at the end of its life, a star of such mass evolves first into a red giant branch star, then an asymptotic giant branch star, and a PN. Dust production in the Milky Way galaxy predominantly comes from mass-loss during these end stages of stellar evolution. However, our understanding of dust creation and evolution largely comes from stars with metallicity close to the solar value. As sensitive observations of dust at lower metallicity are made in distant galaxies, it is imperative that we understand and characterize dust production at low metallicity within our own galactic environment. PNe in the Large Magellanic Cloud (LMC) are ideal targets to study dust production and (dust) mass-loss rate in low- to intermediate-mass stars. Since the distance to the LMC is well determined and they evolved from stars with different metallicity, composition, and initial mass, we can estimate dust mass with less uncertainly and we can discuss relations between dust mass and properties of an ionized nebula and the progenitor star. I have been estimating dust mass in LMC PNe based on the data taken by Spitzer legacy projects SAGE and SAGE-Spec. I will show results of LMC PN dust and introduce ongoing other projects on dust in PNe.
【The Colloquium Committee in 2011】
Risa Kuroshima kuro<at>astr.tohoku.ac.jp <at>-->@