ABSTRACTS OF ORAL PRESENTATIONS

    MEAD: MEASURING EXTINCTION AND ABUNDANCES OF DUST - MARJORIE DECLEIR

    Interstellar dust has a significant impact on many astronomical research fields, as it absorbs and scatters a large fraction of the star light, and influences star formation and galaxy evolution at all cosmic times. Understanding the properties of the dust grains is thus crucial to derive precise knowledge of any object in the Universe that is obscured by dust, as well as to constrain the initial conditions for star and planet formation.
    We can gain insight into the properties of the interstellar dust by studying its extinction effect on the star light. Multi-wavelength continuum extinction contains information about the average dust grain size along the line of sight, while extinction features reveal the composition of the dust grains. In addition, abundances of the elements that make up the dust grains enable us to quantitatively measure the chemical composition of the grains. With the MEAD (Measuring Extinction and Abundances of Dust) project we are combining these two methods to constrain the dust properties in our Galaxy. We obtained ultraviolet spectra with the Hubble Space Telescope to measure dust abundances in a sample of Milky Way sightlines, that span a range of environments. Furthermore, we will combine these abundance measurements with literature UV extinction curves, as well as new near- and mid-infrared extinction curves that we are measuring with our James Webb Space Telescope observations, for the same sightlines.
    In this talk, I will explain the goals of MEAD and walk you through the first results. I will also show how the synergy between multi-wavelength data from the HST and JWST, as well as other telescopes is advancing our understanding of interstellar dust properties and how they vary in our Galaxy.

     

     

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