WATER VAPOR in the PROTOPLANETARY DISK of DG Tau

Transcription

1 WATER VAPOR in the PROTOPLANETARY DISK of DG Tau Linda Podio Institut de Planétologie et d'astrophysique de Grenoble, France I. Kamp (Kapteyn), C. Codella (Oss Arcetri), S. Cabrit (Obs Paris), B. Nisini (Oss Roma), C. Dougados (IPAG), G. Sandell (NASA), J.P. Williams (Hawaii), L. Testi (ESO), W.-F. Thi (IPAG), P. Woitke (St Andrews), R. Meijerink (Kapteyn), M. Spaans (Kapteyn), G. Aresu (Kapteyn), F. Menard (IPAG), C. Pinte (IPAG)

2 PROTOPLANETARY DISKS are the birthplace of planets the study of their physical and chemical structure is fundamental to comprehend the formation of our own solar system & extra-solar planetary systems different lines probes the physical/chemical conditions of the gas located in different regions of the disk X-rays CO low J sub-mm CO ro-vib 2-5 υ m ices UV H2O ro-vib rcond H2O low Tex 10 AU 100 AU Aikawa et al Kamp & Dullemond 2004 Dullemond et al 2007 Bergin et al. 2007

3 What is the origin of WATER ON EARTH? 1 M = e27 g, 1 earth ocean = 1.5e24 g = 2.5e-4 M Matsui & Abe 1986 Drake 2005 Morbidelli Hartogh DRY accretion + late H2O delivery by asteroids/comets Earth --> (D/H) = (1.558 ± 0.001) 1e-4 ~ D/H in Carbonaceus chondrites (ASTEROIDS) and Jupiter-family COMETS Hartogh Lecuyer Balsiger+ 1995, Meier Bockelee-Morvan H/D ratio unaltered in the Earth's crust over time diagnostic of the isotopic composition of the planetesimal that delivered H2O to Earth

4 H2O location & mass in protoplanetary disks R < Rsnow H2O is evaporated H2O gas >> H2O ice R > Rsnow H2O frozen on dust grains H2O gas << H2O ice In the outer disk upper layers H2O photo-desorbed & photo-dissociated Dominik Ceccarelli Kamp X-rays ices UV H2O ro-vib H2O low Tex SNOW LINE Tdust = 150 K Rsnow ~ 2-3 AU Lecar rcond 10 AU 100 AU

5 WATER in PROTOPLANETARY DISKS before HERSCHEL High-exc rotational H2O lines from the HOT INNER DISK water ice absorption from the COLD OUTER DISK (Eup ~ K, T= K, R=0.5-5 AU) Carr & Najita 2008 Salyk Pontoppidan+ 2010a AA Tau Spitzer-IRS (10-36um) AS 205N VLT-VISIR (12-33um) Pontoppidan+ 2010b SUBARU/IRCS 3um water ice absorption HK Tau B, HV Tau C Terada Honda+ 2009

6 HERSCHEL: a NEW window to search WATER in DISKS WISH Water In Star forming regions with Herschel (PI: E. van Dishoeck) DIGIT Dust, Ice, and Gas In Time (PI: N. Evans) GASPS GAS in Protoplanetary Systems (PI: B. Dent) DUNES DUst disks around NEarby Stars (PI: C. Eiroa) DEBRIS Disc Emission via a Bias-free Reconnaissance in the Infrared/Sub-millimetre (PI: B. Matthews) HOT WATER from INNER DISK detected in 8 TTSs in Taurus... H2O 63.32um (Eup ~ 1007 K) Riviere-Marichalar + GASPS 2012 and in 1 Herbig Ae/Be!! HD Meeus + GASPS 2012 Fedele + DIGIT/WISH 2013

7 Both high- & low-exc H2O emission from Class 0/I sources Kristensen+ 2012, Karska HIFI beam H2O 557 GHz and Class II jet-driving sources Podio DG Tau jet + disk + envelope Atomic emission [OI], [CII] lines extended along optical-jet axis, blue- red-shifted Molecular emission H2O, high-j CO lines spectrally and spatially unresolved with PACS!! (DV > 80 km/s, 1 spaxel = 9.4 x 9.4 ) Podio H2O from jet, disk, or envelope? follow-up Herschel/HIFI observations 7 sources in H2O, CO 10-9, [CII] (PI: L. Podio)

8 Herschel/HIFI observations of DG Tau low-exc WATER emission from OUTER DISK! double-peaked profle: strong kinematic evidence of keplerian rotating disk! 557 GHz Eup ~ 61 K Podio H2O line peaks in the velocity ranges where 13CO 2-1 interf maps trace the disk rotation (V gradient perp to jet direction) Rout(H2O) ~ AU ~ Rout(dust) 1.3 mm 1113 GHz Eup ~ 53 K CARMA cont maps Isella Vred Vblue Blue optical jet PA = 226 Testi Rout 2.8 mm

9 WATER is a UNIQUE TRACER of the DISK 13 CO 2-1 OVRO interferometric maps (Testi et al. 2002) Vsys ~ 6 km/s Vblue Vred CO, [CII] lines are dominated by ENVELOPE/OUTFLOW emission Only interferometric obs in an optically thin tracer - 13CO 2-1 disentangle extended vs compact emission H2O lines - even when obs with single-dish seems to be dominated by COMPACT emission!

10 DISK model: the region emitting low-exc H2O lines Protoplanetary Disk Models (ProDiMo) Woitke+ 2009, Kamp+ 2010, Thi Aresu+ 2011, 2012, Meijerink uses global iterations to consistently calculate physical, thermal, chemical structure of protoplanetary disks. large chemical network: 120 species, ~1650 reactions H2O 557, 1113 GHz (HIFI) H2O 179.5um (PACS) emitted by same disk region R = AU T = K < nh > = 1e8 1e10 cm-3 --> H2O emission close to LTE --> optically thick lines Snow-line Podio+ 2013Tdust = 150 K observed line fuxes in agreement with predicted ones within a factor 2 Model uncertainty related to: collisional rates, chemistry on dust grains (e.g. desorption and adsoprtion rates) details of radiative transfer Kamp+ 2013

11 Estimating the WATER RESERVOIR in the DISK dust grain size distribution / disk dust mass to reproduce cont emission at 1.3, 2.8 mm (Isella+ 2010): low dust opacity model high dust opacity model Mdisk = 0.1 M8 Mdisk = M8 H2Ogas ~ 1e-6 M8 ~ 0.37 M H2Ogas ~ 1.7e-7 M8 ~ 0.06 M H2Oice ~ 3e-4 M8 ~ 100 M H2Oice ~ 2e-5 M8 ~ 7 M Since H2O lines are optically thick disk and water masses are constrained with one order of magnitude uncertainty Mdisk = M8 Minimum Mass of the Solar Nebula (MMSN) before planets formation M(H2O) ~ M ~ 1e4-1e5 earth oceans supports the scenario of impact delivery of water on terrestrial planets by means of icy bodies forming in the outer disk

12 ONLY 2 detections of WATER from the outer disk!! + 1 upp limit in DM Tau (Bergin et al. 2010) +? TW Hya Hogerheijde+ 11 DG Tau Podio+ 13 1st detection in TW Hya d = 50pc, ~10 Myr Macc ~ 1e-9 M8/yr fuv = LUV/L* = H2O sub-thermally excited in a region at T ~ K disk: Rout=200 AU, Mdisk= M8 M (H2O) ~ 1.5 M 2nd detection in DG Tau F(H2O) ~ 19-26x brighter d = 140pc, ~2.5 Myr Macc ~ 5e-7 M8/yr fuv = LUV/L* = 0.2 H2O excited close to LTE in a region at T ~ K disk: Rout=100 AU, Mdisk= M8 M (H2O) ~ M a few-100x H2O than TW Hya!

13 WATER in protoplanetary disks: future perspectives Herschel: clear detection of low-exc H2O only in two protoplanetary disks: 1. A closeby source (TW Hya, Hogerheijde+ 2011) 2. A source associated with very intense UV and X-ray feld (DG Tau, Podio+ 2013) Observations from space with SPICA + JWST SPICA is more sensitive than Herschel (2e-19 W/m2) R ~ at 12-18um Observations from ground H2O rovibrational lines with NIR high resolution spectrometer (e.g., VLT/CRIRES, Keck/NIRSPEC) H2O spectral profle (e.g. Pontoppidan+ 2010b, Salyk+ 2008) Mm interferometers (e.g. IRAM/PdBI, SMA, ALMA) Resolved disk map in H218O = optically thin tracer direct estimate of H2O location and mass Or in typical disk tracers CO, CN, HCN constraints on disk structure (size, T)