The millimeter continuum size-frequency relationship in the UZ Tau e Disk

• Verfasst von: Tripathi, Anjali [VerfasserIn]
• Verfasst von: Henning, Thomas [VerfasserIn]
• Verfasst von: Linz, Hendrik [VerfasserIn]
• Titel: The millimeter continuum size-frequency relationship in the UZ Tau e Disk
• Verf.angabe: Anjali Tripathi, Sean M. Andrews, Tilman Birnstiel, Claire J. Chandler, Andrea Isella, Laura M. Pérez, R.J. Harris, Luca Ricci, David J. Wilner, John M. Carpenter, N. Calvet, S.A. Corder, A.T. Deller, C.P. Dullemond, J.S. Greaves, Th Henning, W. Kwon, J. Lazio, H. Linz, and L. Testi
• E-Jahr: 2018
• Jahr: 2018 July 3
• Umfang: 12 S.
• Fussnoten: Gesehen am 20.05.2019
• Titel Quelle: Enthalten in: The astrophysical journal / 1
• Ort Quelle: London : Institute of Physics Publ., 1996
• Jahr Quelle: 2018
• Band/Heft Quelle: 861(2018,1) Artikel-Nummer 64, 12 Seiten
• ISSN Quelle: 1538-4357
• DOI: doi:10.3847/1538-4357/aac5d6
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1665939060

Abstract

We present high spatial resolution observations of the continuum emission from the young multiple star system UZ Tau at frequencies from 6 to 340 GHz. To quantify the spatial variation of dust emission in the UZ Tau E circumbinary disk, the observed interferometric visibilities are modeled with a simple parametric prescription for the radial surface brightnesses at each frequency. We find evidence that the spectrum steepens with radius in the disk, manifested as a positive correlation between the observing frequency and the radius that encircles a fixed fraction of the emission (R eff ∝ ν 0.34±0.08). The origins of this size-frequency relation are explored in the context of a theoretical framework for the growth and migration of disk solids. While that framework can reproduce a similar size-frequency relation, it predicts a steeper spectrum than that observed. Moreover, it comes closest to matching the data only on timescales much shorter (≤1 Myr) than the putative UZ Tau age (∼2-3 Myr). These discrepancies are direct consequences of the rapid radial drift rates predicted by models of dust evolution in a smooth gas disk. One way to mitigate that efficiency problem is to invoke small-scale gas pressure modulations that locally concentrate drifting solids. If such particle traps reach high-continuum optical depths at 30-340 GHz with a ∼30%-60% filling fraction in the inner disk (r ≲ 20 au), they can also explain the observed spatial gradient in the UZ Tau E disk spectrum.