Scattering and sublimation: A multiscale view of μm-sized dust in the inclined disc of HD 145718
Author
Davies, C.L.Rich, E.A.
Harries, T.J.
Monnier, J.D.
Laws, A.S.E.
Andrews, S.M.
Bae, J.
Wilner, D.J.
Anugu, N.
Ennis, J.
Gardner, T.
Kraus, S.
Labdon, A.
Le Bouquin, J.-B.
Lanthermann, C.
Schaefer, G.H.
Setterholm, B.R.
Ten Brummelaar, T.
Affiliation
Steward Observatory, Department of Astronomy, University of ArizonaIssue Date
2022Keywords
AccretionAccretion discs
Circumstellar matter
Radiative transfer
Stars: formation
Stars: individual: HD 145718
Techniques: high angular resolution
Metadata
Show full item recordPublisher
Oxford University PressCitation
Davies, C. L., Rich, E. A., Harries, T. J., Monnier, J. D., Laws, A. S. E., Andrews, S. M., Bae, J., Wilner, D. J., Anugu, N., Ennis, J., Gardner, T., Kraus, S., Labdon, A., Le Bouquin, J.-B., Lanthermann, C., Schaefer, G. H., Setterholm, B. R., & Ten Brummelaar, T. (2022). Scattering and sublimation: A multiscale view of μm-sized dust in the inclined disc of HD 145718. Monthly Notices of the Royal Astronomical Society.Rights
Copyright © 2022 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
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 ∼ 75 au and we infer an aspect ratio, hscat(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/2πin 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. © 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.Note
Immediate accessISSN
0035-8711Version
Final published versionae974a485f413a2113503eed53cd6c53
10.1093/mnras/stac149