Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya Constraining the disk gas mass
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Author
Thi, W. -F.
Mathews, G.
Menard, F.
Woitke, P.
Meeus, G.
Riviere-Marichalar, P.
Pinte, C.
Howard, C. D.
Roberge, A.
Sandell, G.
Pascucci, I.
Riaz, B.
Grady, C. A.
Dent, W. R. F.
Kamp, I.
Duchene, G.
Augereau, J. -C.
Pantin, E.
Vandenbussche, B.
Tilling, I.
Williams, J. P.
Eiroa, C.
Barrado, D.
Alacid, J. M.
Andrews, S.
Ardila, D. R.
Aresu, G.
Brittain, S.
Ciardi, D. R.
Danchi, W.
Fedele, D.
de Gregorio-Monsalvo, I.
Heras, A.
Huelamo, N.
Krivov, A.
Lebreton, J.
Liseau, R.
Martin-Zaidi, C.
Mendigutia, I.
Montesinos, B.
Mora, A.
Morales-Calderon, M.
Nomura, H.
Phillips, N.
Podio, L.
Poelman, D. R.
Ramsay, S.
Rice, K.
Solano, E.
Walker, H.
White, G. J.
Wright, G.
Attention
2299/7278
Abstract
Planets are formed in disks around young stars. With an age of similar to 10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel-PACS to directly study their gaseous component. We aim to constrain the gas and dust mass of the circumstellar disk around TW Hya. We observed the fine-structure lines of [OI] and [CII] as part of the open-time large program GASPS. We complement this with continuum data and ground-based (12) CO 3-2 and (CO)-C-13 3-2 observations. We simultaneously model the continuum and the line fluxes with the 3D Monte-Carlo code MCFOST and the thermo-chemical code ProDiMo to derive the gas and dust masses. We detect the [OI] line at 63 mu m. The other lines that were observed, [OI] at 145 mu m and [CII] at 157 mu m, are not detected. No extended emission has been found. Preliminary modeling of the photometric and line data assuming [(CO)-C-12]/[(CO)-C-13] = 69 suggests a dust mass for grains with radius < 1 mm of similar to 1.9 x 10(-4) M-circle dot (total solid mass of 3 x 10(-3) M-circle dot) and a gas mass of (0.5-5) x 10(-3) M-circle dot. The gas-to-dust mass may be lower than the standard interstellar value of 100.