Details

Autor(en) / Beteiligte

• Defrère, D.
• Hinz, P. M.
• Skemer, A. J.
• Kennedy, G. M.
• Bailey, V. P.
• Hoffmann, W. F.
• Mennesson, B.
• Millan-Gabet, R.
• Danchi, W. C.
• Absil, O.
• Arbo, P.
• Beichman, C.
• Brusa, G.
• Bryden, G.
• Downey, E. C.
• Durney, O.
• Esposito, S.
• Gaspar, A.
• Grenz, P.
• Haniff, C.
• Hill, J. M.
• Lebreton, J.
• Leisenring, J. M.
• Males, J. R.
• Marion, L.
• McMahon, T. J.
• Montoya, M.
• Morzinski, K. M.
• Pinna, E.
• Puglisi, A.
• Rieke, G.
• Roberge, A.
• Serabyn, E.
• Sosa, R.
• Stapeldfeldt, K.
• Su, K.
• Vaitheeswaran, V.
• Vaz, A.
• Weinberger, A. J.
• Wyatt, M. C.

Titel

FIRST-LIGHT LBT NULLING INTERFEROMETRIC OBSERVATIONS: WARM EXOZODIACAL DUST RESOLVED WITHIN A FEW AU OF η Crv

Ist Teil von

• The Astrophysical journal, 2015-01, Vol.799 (1), p.42

Ort / Verlag

United States: IOP Publishing

Erscheinungsjahr

2015

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• We report on the first nulling interferometric observations with the Large Binocular Telescope Interferometer (LBTI), resolving the N' band (9.81-12.41 μm) emission around the nearby main-sequence star η Crv (F2V, 1-2 Gyr). The measured source null depth amounts to 4.40% ± 0.35% over a field-of-view of 140 mas in radius (~2.6 AU for the distance of η Crv) and shows no significant variation over 35° of sky rotation. This relatively low null is unexpected given the total disk to star flux ratio measured by the Spitzer Infrared Spectrograph (IRS; ~23% across the N' band), suggesting that a significant fraction of the dust lies within the central nulled response of the LBTI (79 mas or 1.4 AU). Modeling of the warm disk shows that it cannot resemble a scaled version of the solar zodiacal cloud unless it is almost perpendicular to the outer disk imaged by Herschel. It is more likely that the inner and outer disks are coplanar and the warm dust is located at a distance of 0.5-1.0 AU, significantly closer than previously predicted by models of the IRS spectrum (~3 AU). The predicted disk sizes can be reconciled if the warm disk is not centrosymmetric, or if the dust particles are dominated by very small grains. Both possibilities hint that a recent collision has produced much of the dust. Finally, we discuss the implications for the presence of dust for the distance where the insolation is the same as Earth's (2.3 AU).