An interferometric study of the Fomalhaut inner debris disk. I. Near-infrared detection of hot dust with VLTI-VINCI - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




An interferometric study of the Fomalhaut inner debris disk. I. Near-infrared detection of hot dust with VLTI-VINCI - Astrophysics > Solar and Stellar Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: The innermost parts of dusty debris disks around main sequence stars arecurrently poorly known due to the high contrast and small angular separationwith their parent stars. Using near-infrared interferometry, we aim to detectthe signature of hot dust around the nearby A4 V star Fomalhaut, which hasalready been suggested to harbor a warm dust population in addition to a colddust ring located at about 140 AU. Archival data obtained with the VINCIinstrument at the VLTI are used to study the fringe visibility of the Fomalhautsystem at projected baseline lengths ranging from 4 m to 140 m in the K band. Asignificant visibility deficit is observed at short baselines with respect tothe expected visibility of the sole stellar photosphere. This is interpreted asthe signature of resolved circumstellar emission, producing a relative flux of0.88% +- 0.12% with respect to the stellar photosphere. While ourinterferometric data cannot directly constrain the morphology of the excessemission source, complementary data from the literature allow us to discard anoff-axis point-like object as the source of circumstellar emission. We arguethat the thermal emission from hot dusty grains located within 6 AU fromFomalhaut is the most plausible explanation for the detected excess. Our studyalso provides a revised limb-darkened diameter for Fomalhaut 2.223 +- 0.022mas, taking into account the effect of the resolved circumstellar emission.



Author: Olivier Absil, Bertrand Mennesson, Jean-Baptiste Le Bouquin, Emmanuel Di Folco, Pierre Kervella, Jean-Charles Augereau

Source: https://arxiv.org/







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