دورية أكاديمية

Scattering and sublimation: a multiscale view of µm-sized dust in the inclined disc of HD 145718.

التفاصيل البيبلوغرافية
العنوان: Scattering and sublimation: a multiscale view of µm-sized dust in the inclined disc of HD 145718.
المؤلفون: Davies, Claire L, Rich, Evan A, Harries, Tim J, Monnier, John D, Laws, Anna S E, Andrews, Sean M, Bae, Jaehan, Wilner, David J, Anugu, Narsireddy, Ennis, Jacob, Gardner, Tyler, Kraus, Stefan, Labdon, Aaron, le Bouquin, Jean-Baptiste, Lanthermann, Cyprien, Schaefer, Gail H, Setterholm, Benjamin R, ten Brummelaar, Theo, collaboration, G-LIGHTS
المصدر: Monthly Notices of the Royal Astronomical Society; Apr2022, Vol. 511 Issue 2, p2434-2452, 19p
مصطلحات موضوعية: SURFACE scattering, MINERAL dusts, RADIATIVE transfer, GEOMETRIC analysis, CIRCUMSTELLAR matter, STAR formation, DUST
مستخلص: We present multi-instrument observations of the disc around the Herbig Ae star, HD 145718, employing geometric and Monte Carlo radiative transfer models to explore the disc orientation, the vertical and radial extent of the near-infrared (NIR) scattering surface, and the properties of the dust in the disc surface and sublimation rim. The disc appears inclined at 67–71°, with position angle, PA = −1.0 to 0.6°, consistent with previous estimates. The NIR scattering surface extends out to |${\sim}75\,$| au and we infer an aspect ratio, h scat(r)/ r ∼ 0.24 in J band; ∼0.22 in H band. Our Gemini Planet Imager images and VLTI + CHARA NIR interferometry suggest that the disc surface layers are populated by grains ≳λ/2π in size, indicating these grains are aerodynamically supported against settling and/or the density of smaller grains is relatively low. We demonstrate that our geometric analysis provides a reasonable assessment of the height of the NIR scattering surface at the outer edge of the disc and, if the inclination can be independently constrained, has the potential to probe the flaring exponent of the scattering surface in similarly inclined (i ≳ 70°) discs. In re-evaluating HD 145718's stellar properties, we found that the object's dimming events – previously characterized as UX Or and dipper variability – are consistent with dust occultation by grains larger, on average, than found in the ISM. This occulting dust likely originates close to the inferred dust sublimation radius at |$0.17\,$| au. [ABSTRACT FROM AUTHOR]
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قاعدة البيانات: Complementary Index
الوصف
تدمد:00358711
DOI:10.1093/mnras/stac149