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| Paper: |
Probing the Variations of Interstellar Dust Abundance and Properties Within and Between Galaxies with HWO UV Spectroscopy in the Local Volume |
| Monograph: |
10, HWO25 Proceedings Part I: Community Science Case Development Documents |
| Page: |
97 |
| Authors: |
Julia Roman-Duval; Mederic Boquien; Yumi Choi |
| DOI: |
10.26624/DRNL2690 |
| Abstract: |
The cycle of metals between the gas and the dust phases in the neutral interstellar medium (ISM) is an
integral part of the baryon cycle in galaxies. The resulting variations in the abundance and properties of
interstellar dust have important implications for how accurately we can trace the chemical enrichment of
the universe over cosmic time. Multi-object UV spectroscopy with HWO can provide the large samples
of abundance and dust depletion measurements needed to understand how the abundance and properties of
interstellar dust vary within and between galaxies, thereby observationally addressing important questions
about chemical enrichment and galaxy evolution. Medium-resolution (R∼50,000) spectroscopy in the full
UV range (950–3150 Angstrom) toward massive stars in Local Volume galaxies (D<10 Mpc) will enable gas-
and dust-phase abundance measurements of key elements, such as Fe, Si, Mg, S, Zn. These measurements
will provide an estimate of how the dust abundance varies with environment, in particular metallicity and
gas density. However, measuring the carbon and oxygen contents of dust requires very high resolution
(R>100,000) and high signal-to-noise (S/N>100) owing to the non-saturated UV transitions for those
elements being extremely weak. Since carbon and oxygen in the neutral ISM contribute the largest metal
mass reservoir for dust, it is critical that the HWO design include a grating similar to the HST STIS H gratings
providing very high resolution, as well as FUV and NUV detectors capable of reaching very high S/N. |
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