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Published May 2012 | Published
Journal Article Open

Confirming the Primarily Smooth Structure of the Vega Debris Disk at Millimeter Wavelengths


Clumpy structure in the debris disk around Vega has been previously reported at millimeter wavelengths and attributed to concentrations of dust grains trapped in resonances with an unseen planet. However, recent imaging at similar wavelengths with higher sensitivity has disputed the observed structure. We present three new millimeter wavelength observations that help to resolve the puzzling and contradictory observations. We have observed the Vega system with the Submillimeter Array (SMA) at a wavelength of 880 μm and an angular resolution of 5"; with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) at a wavelength of 1.3 mm and an angular resolution of 5"; and with the Green Bank Telescope (GBT) at a wavelength of 3.3 mm and angular resolution of 10". Despite high sensitivity and short baselines, we do not detect the Vega debris disk in either of the interferometric data sets (SMA and CARMA), which should be sensitive at high significance to clumpy structure based on previously reported observations. We obtain a marginal (3σ) detection of disk emission in the GBT data; the spatial distribution of the emission is not well constrained.We analyze the observations in the context of several different models, demonstrating that the observations are consistent with a smooth, broad, axisymmetric disk with inner radius 20–100 AU and width ≾50 AU. The interferometric data require that at least half of the 860 μm emission detected by previous single-dish observations with the James Clerk Maxwell Telescope be distributed axisymmetrically, ruling out strong contributions from flux concentrations on spatial scales of ≾100 AU. These observations support recent results from the Plateau de Bure Interferometer indicating that previous detections of clumpy structure in the Vega debris disk were spurious.

Additional Information

© 2012 American Astronomical Society. Received 2011 November 7; accepted 2012 February 27; published 2012 April 17. We thank Mark Wyatt for providing us with his model of the planetesimal distribution in the Vega system. The authors also thank the MUSTANG instrument team from the University of Pennsylvania, NRAO, Cardiff University, NASA-GSFC, and NIST for their efforts on the instrument and software that have made this work possible. The GBT data were obtained under the auspices of observing program AGBT08C026. A.M.H. is supported by a fellowship from the Miller Institute for Basic Research in Science. S. Dicker is supported by NSF AST- 1007905. A.H. acknowledges support from Millennium Science Initiative, Chilean Ministry of Economy: Nucleus P10-022-F. E.C. acknowledges support by NSF grant AST-0909210.

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Published - Hughes2012p18213Astrophys_J.pdf


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August 22, 2023
October 17, 2023