Transitional disks with SPHERE

Transcription

1 Transitional disks with SPHERE Juan Manuel Alcalá INAF- Napoli A. Natta, C. Manara, L Testi E. Covino, E. Rigliaco, B. Stelzer and Italian X-Shooter GTO team

2 Evolution of disc/envelope & accretion 10 Myr cores Disc / envelope Debris disc (Fedele et al. 2010) t=0 Class 0 t= yr Class I Class II t > 10 7 yr Class III

3 Spitzer results on transitonal disks Transition YSOs are a diverse class Variable inner hole sizes, ranging from a few AU to tens of AU The diversity of these YSOs probably reflects diversity among their presumed precursors, the T Tauri stars, and consequent multiple paths to forming planetary systems Production of an inner hole by a) giant planet: rapid draining from inner disc b) photoevaporation accretion Adapted from G. Bryden dm pe /dt dm acc /dt

4 Accretion diagnostics Flux [erg s -1 cm -2 nm -1 ] infall UV excess emission T ~10 4 K shock gas emits in: Balmer & Paschen continua Balmer & Paschen series CaII IRT, He I outflow G M M acc R L UV L acc = (1 - ) R R in log (L acc / L ʘ ) = 1.09 log(l UV /L ʘ ) (Gullbring et al. 1998) modelling continuum excess emission best to estimate L acc VLT: cover from UV to NIR

5 Planet formation in transitional discs core-accretion model: accretion of gas onto rocky / icy cores of ~10M earth (Lissauer 1993; Pollack et al. 1996; Kornet et al ) grav. instability: overdense clumps (Boss 2003) quick gas dissipation (<< 10Myr) Amount of gas in TDs?

6 Accretion in TDs: X-Shooter Italian GTO Alcala et al. (2014) Merín et al. (2010) R in (AU) = 55 i (deg) = 45 Macc = M yr -1 Sz91: Tsukagoshi et al. (2014) 345GHz (870 m): Mauna Kea K S -band & polarim. : SUBARU R in (AU) = 65 R out (AU) = 170 i (deg) = 40 Macc = M yr -1

7 T Cha SED Rdisc T Cha 0.07AU 0.1AU 12AU we estimate Macc 2x10-9 M yr -1 single-disc SED model cannot reproduce the observations high-res. spectroscopy: 10 km/s RV variations, hence giant planet or BD companion? Huelamo et al. (2011): NACO direct imaging; 80M JUP companion 7AU Brown et al. (2007) & Olofsson et al. (2013): inner hole (from near-ir) & disc gap (from mid-ir) Sacco et al. (2014): CO lines with Keplerian profile and M disc (H 2 ) 80 M

8 T Cha SED (Olofsson et al. Rdisc 2013) T Cha 0.07AU 0.1AU 12AU we estimate Macc 2x10-9 M yr -1 single-disc SED model cannot reproduce the observations high-res. spectroscopy: 10 km/s RV variations, hence giant planet or BD companion? Huelamo et al. (2011): NACO direct imaging; 80M JUP companion 7AU Brown et al. (2007) & Olofsson et al. (2013): inner hole (from near-ir) & disc gap (from mid-ir) Sacco et al. (2014): CO lines with Keplerian profile and M disc (H 2 ) 80 M

9 T Cha SED (Sacco et al. 2014) (Olofsson et al. Rdisc 2013) T Cha 0.07AU 0.1AU 12AU we estimate Macc 2x10-9 M yr -1 single-disc SED model cannot reproduce the observations high-res. spectroscopy: 10 km/s RV variations, hence giant planet or BD companion? Huelamo et al. (2011): NACO direct imaging; 80M JUP companion 7AU Brown et al. (2007) & Olofsson et al. (2013): inner hole (from near-ir) & disc gap (from mid-ir) Sacco et al. (2014): CO lines with Keplerian profile and M disc (H 2 ) 80 M

10 X-Shooter (Manara et al. 2014) Accretion: normal vs. transition discs R in [pix] 150pc) Lupus YSOs (Alcala et al. 2014) T Cha LkCa15 R in from no evident Macc vs. disc-cavity correlation no significant difference between Macc of accreting TDs and CTTs no differences between PTDs and TDs density of inner gaseous disc independent on the mechanism that produces the cavity or gap (Alcala et al. in prep.)

11 Slow winds also in transitional discs X-Shooter (Manara et al. 2014) Low Velocity Component of the [OI] line detected in 17 of 22 YSOs with TDs line blue-shifted by a few km/s as in CTTS

12 Slow winds: normal vs. transition discs Manara et al. (2014) Lupus YSOs (Natta et al. 2014) no difference of the L[OI] properties in accreting TDs and CTTs L[OI] insensitive to the size of cavity in TDs: no L[OI] vs. R in correlation L[OI] depends mostly on EUV and X-ray luminosity, but no correlation with L X or Lacc, but Lacc correlates with L UV models explaining the formation of the dust-depleted inner region should leave almost unaltered the gas properties of the innermost region Alternatively

13 Accreting planets! Owen (2014): modelling of TDs with accreting planets L acc may be due to accretion onto planets M planet 3 4 M jup Model can explain Macc M /yr in TDs with a planet HST observations (Zhou, Herczeg et al. 2014): 3 accreting planetary-mass objects HST UV continuum-excess measurements

14 Lk Ca15: work in progress (Whelan et al., in prep.) Kraus & Irelan (2012): proto-planet with dusty material? 6 15 M 15 AU Accreting planet: L acc diagnostics follow the planet apply Spectro-Astrometry (SA) VLT (0.16 / pix) 1.3mm emission

15 Lk Ca15: work in progress (Whelan et al., in prep.) Kraus & Irelan (2012): proto-planet with dusty material? 6 15 M 15 AU Accreting planet: L acc diagnostics follow the planet apply Spectro-Astrometry (SA) VLT (0.16 / pix) 1.3mm emission

16 Lk Ca15: work in progress (Whelan et al., in prep.) Kraus & Irelan (2012): proto-planet with dusty material? 6 15 M 15 AU Accreting planet: L acc diagnostics follow the planet apply Spectro-Astrometry (SA) VLT (0.16 / pix) 1.3mm emission

17 Lk Ca15: work in progress (Whelan et al., in prep.) Kraus & Irelan (2012): proto-planet with dusty material? 6 15 M 15 AU Accreting planet: L acc diagnostics follow the planet apply Spectro-Astrometry (SA) VLT (0.16 / pix) 1.3mm emission 2 PAs in 3 epochs (6 spectra) no SA signal detected (Pa, Pa ) TBD: Balmer, He & Ca lines next: UVES data (+ T Cha )

18 Dust filtration in TDs Another possibility to explain the SEDs in TDs: continuous radial distribution of very small grains (< 1 m) significant depletion of big grains (> 1mm) in the inner disc regions Differentiation of big and small dust grain distributions dust filtration mechanism Basic long-standing problem on planet formation The one-meter barrier how dust particles can grow-up to large sizes ( 1m) without being draged towards the star by radial drift?

19 Modelling of (r) in TDs with a planet (Pinilla et al. 2012) 2D hydrodynamical simulations self-consistent calculations of radial drift, coagulation and fragmentation = c s h, M p, r p, and typical T Tauri parameters (Ms, Mdisk, Rdisk) 1.3mm symulated emission of LkCa15 presure gradient: Vgas specific r reduces (Vgas Vdust) : reduces the drag force on dust large dust particles ( 1mm) r(p max ) dust distribution and r(p max ) depend on M p and r p dust distribution from direct imaging constrain M p and r p

20 Symulated images (de Juan Ovelar et al. 2013)

21 Symulated images (de Juan Ovelar et al. 2013)

22 Lupus YSO VLT UT2 36 well characterized YSOs: Macc already at hand X-Shooter (PI Alcala): complete Macc measurements ALMA cycle-2 survey 92 YSOs (PI Williams): Mdisk The most complete sample of YSOs with M acc, M star, M disk Disk group

23 Napoli Alcala, Covino Arcetri Bacciotti, Codella, Natta, Podio Catania Biazzo, Frasca Roma Antoniucci, Giannini, Li Causi, Lorenzetti, Nisini, Santangelo Palermo Bonito, Stelzer ESO Manara, Tazzari, Testi