Are we seen the effects of forming planets in primordial disks?

1. Are we seen the effects of forming planets in primordial disks? Laura Ingleby, Melissa McClure, Lucia Adame, Zhaohuan Zhu, Lee Hartmann, Jeffrey Fogel, Ted Bergin (U Michigan) Paola D’Alessio (UNAM) Catherine Espaillat (CfA) Dan Watson (Rochester), and IRS disk team James Muzerolle (STScI) Cesar Briceño, Jesus Hernández (CIDA) Kevin Luhman (Penn State) David Wilner, Charlie Qi, Sean Andrews, Meredith Hughes (CfA)

2. Inner Disk Holes: Transitional disks Disk Gaps:Pre-transitional disks “Full” disks Which disks? “Primordial”, gas-rich disks: 99% gas Full disks Disks with inner clearing and with gaps: Transitional disks Pre-transitional disks ? ?

3. Full disks: Accretion disks Ingleby & Calvet 2010 UV excess Lacc = GM(dM/dt)/R Photosphere Gullbring et al 1998 Calvet & D’Alessio 2009 Mass accretion rate onto the star

4. Full disks: Irradiated Accretion disks Self-consistent calculation of Σ from dM/dt (UV measurements) and T structure UV excess Photosphere

5. Contributors to the SED M0, ε = 0.001, α = 0.001 star wall disk McClure and IRS Disk team 2010b

6. Transitional disks Strom et al. 1989, inner disk clearings and disks in transition TW Hya, 10 Myr old Taurus median • Near to mid-IR flux deficit relative to Taurus median • Sharp rise at mid-IR • Flux at longer l‘s consistent with optically thick emission Calvet et al 2002

7. Names, names … Many “definitions” of transition disks, anything “in between” Taurus optically thick disks and photospheres/Class III In this talk, transitional disks: near IR close to photosphere mid-far IR comparable to Taurus Hernandez et al 2007, 2008, 2010 transitional evolved

8. Agent of evolution: Viscous disk evolution t=0 Hartmann 2009 • As t increases: • Disk expands, S decreases, the disk mass falls as 1/t1/2 (lost to the star) • Transition between dependence 1/R (~ steady disk) and exponential at larger radius S a 1/R (similar to steady disk) Exponential cut-off

9. Mass accretion rate decreases with time Viscous evolution Hartmann et al. (1998), Muzerolle et al. (2001), Calvet et al. (2005) .50 .23 .12 Fraction of accreting objects decreases with time: not explained by viscous evolution

10. Disk frequency decreases with age of population Hernandez et al 2010

11. Agent of evolution: dust in disk Median and quartiles of excess emission over photosphere Near IR excess decreases with age of population Age not the only parameter determining evolution Hernandez et al. 2008

12. Dust growth and settling t = 0 Upper layers get depleted Weidenschilling 1997; Dullemond & Dominik 2004

13. Effects of dust settling in SED IRS depletion D’Alessio et al 2006

14. Disks settle very early Even at populations as young as those in the Ophiuchus clouds, ~ 0.5 - 1 Myr, disks are as settled as in Taurus  = dust to mass ratio of small dust in upper layers relative to standard ratio McClure and IRS Disk Team 2010a

15. Art by Luis Belerique & Rui Azevedo Gas and dust evolutionary effects in inner disk Inner disk: D’Alessio et al 2006 wall disk Slope becomes stepper as: • Degree of settling increases • Accretion rate decreases log dM/dt= -10, -9, -8, -7 S decreases

16. The “Evolved” disks Hernandez et al 2007, 2008 Evolved disks consistent with low accretion rates and high degree of depletion

17. Agent of evolution: photoevaporation High energy radiation photoevaporates outer disk When mass accretion rate (decreasing by viscous evolution) ~ mass loss rate, no mass reaches inner disk Evolution with photoeva-poration Rg Evolution without photoeva-poration Clarke et al 2001

18. Direct and indirect effects of photoevaporation Photoevaporation effects depend on strength of high energy (EUV, FUV, X-ray) fields, set the mass loss rate in the disk upper layers When mass accretion rate ~ mass loss rate, inner disk is depleted in viscous time scale of inner disk If hole, direct photoevaporation of hole edge, inner cleared region grows fast (Alexander & Armitage 2008, 2009) Critical mass loss rate from ~ 10-10 Msun/yr to 10-8 Msun/yr (Owen et al. 2010) Difficult to understand low dM/dt’s Line profiles? Extent of [OI] emission? Gorti’s talk

19. Extent of Hα and [OI] emission HST images of DG Tau jet, Kepner et al 1993

20. Important in evolved disks Low dM/dt Low disk masses Cieza 2008

21. Agent of evolution: planets forming in disk Formed as consequence of dust evolution if core accretion Open gaps in disks; dynamical clearing Zhu et al 2010

22. Effects on SED Rice et al 2003 Inner clear region Rise due to frontally illuminated wall Contrast depends on mass of planet

23. Optically thick outer disk wall Optically thin region | 56 AU Transitional disks TW Hya, 10 Myr old • Emission from wall of truncated outer disk • Optically thin emission in inner disk Calvet et al 2002

24. Transitional disks in Taurus Rw ~ 24AU outer disk + inner disk with little dust + gap (~ 5-24AU) Optically thin material Rw ~ 3 AU only external disk Accreting  gas in inner disk Calvet et al 2005

25. Transitional disks: gas in inner disk Excess over photosphere: emission from accretion shock on stellar surface TW Hya Ingleby et al 2010

26. Imaging of holes with sub/mm SMA interferometry IRS spectra finely maps disk structure GM Aur Hughes et al 2009 Inner regions evacuated of mm-size grains

27. Circumbinary disks CoKu Tau 4, ~ 10 AU ~ 2 Myr Binary system (Ireland & Kraus 2008) Other cases: HD98800 Furlan et al. 2007 Hen3-600A Uchida et al 2004 Check for companions Tidal interactions clear inner disks Forrest et al. 2004; D’Alessio et al. 2005

28. What agent clears the inner disk regions? Planets most likely • Lubow & d’Angelo 2006: • Some mass of outer disk into planet • Disks more massive than expected from (dM/dt) Alexander & Armitage 2007 Transitional disks Planet Photoevaporation Najita, Strom, & Muzerolle 2007

29. Espaillat et al. 2007b UX Tau A median Taurus SED = optically thick full disk Best-fit model Outer wall Optically thick inner disk wall photosphere large excess, ~optically thick disk Optically thick outer disk wall | 56 AU Pre-Transitional Disks: optically thick disks with gaps Outer disk Optically thick inner disk

30. median Taurus SED = optically thick full disk thick photosphere thin large excess, ~optically thick disk Pre-Transitional Disk of LkCa 15 • Truncated outer disk at ~ 46 AU (Pietu et al. 2006) • Binary? No companion M > 0.1 Msun 3-22 AU (Ireland & Krauss 2008; Pott et al 2010) or larger separations (White & Ghez 2001) Two possibilities Increasing flux/ optically thick disk

31. Detailed near-IR spectrum of pre-transitional disk LkCa 15 Blackbody at T ~ 1500K Standard 2-5 mm SpeX spectrum Espaillat et al. 2008 Optically thick material in inner disk  gap in primordial disk

32. Art by Luis Belerique & Rui Azevedo Blackbody-like near-IR excess between 2-5 mm in full disks of CTTS Muzerolle et al. 2003

33. Dust-gas Transition Monnier & Millan-Gabet 2002

34. Detailed near-IR spectra of pre-transitional and transitional disks Transitional disk: no hot optically thick material Espaillat et al. 2010

35. Structure of inner disk Inner disk shadowing outer wall? Mulders, Dominik, & Min 2010 Disk with gap - Pre-transitional Penumbra Disk with inner clearing – Transitional Umbra Height of wall ~ height of disk behind it, as modeled from SED Espaillat et al 2010

36. Edge detected in scattered light Subaru HiCiao H images of LkCa 15 Hole ~ 46 AU consistent with SED and mm interferometry Contrast ⇒< 21 Mjup outside14 AU Pericenter offset ~ 9AU, supports dynamical effects due to planets Thalmann et al 2010

37. Can planets really make pre/transitional disks? • Three conditions from properties of transitional disks – accreting objects with “holes” detected from mm interferometry • Accretion rate onto the star ≥ 10-9 Msun/yr • Large, ~ 10’s AUs, gaps/holes • Low optical depth in gaps, despite having gas flowing through it • Models so far not quite fulfill all conditions • Photoevaporation can open holes and clear disks, but low dM/dt , important at later stages • If significant accretion by planet(s), then dM/dt (*) too low • 1 planet cannot open wide enough gap

38. Can planets really make pre/transitional disks? Fargo 2-D simulations of gap opening by planets Increasing mass accreted by planet Zhu et al 2010

39. Can planets really make pre/transitional disks? Fargo 2-D simulations of gap opening by 4 planets Mplanets =0.1 MJ, varying accretion rate onto planets Zhu et al 2010

40. Can planets really make pre/transitional disks? Require multiple planets to make large gaps that last Require high levels of dust depletion in gap and inside to make material optically thin Dust filtration gap edge? (Rice et al. 2006): Small grains make it through and grow No large dust to make small dust by collisions (Dullemond & Dominik 2005) Zhu et al 2010

41. Prospects for Herschel: Settling and grain growth at midplane Effects of dust settling more conspicuous in Herschel range Grain growth at midplane IRS Herschel depletion PACS, Spires photometry of disks in nearby regions, Gould belt + OT1 D’Alessio et al 2006

42. Prospects for Herschel: Disk masses Preliminary GASPS results indicate that the disk mass of TW Hya is 0.5 – 5 x 10-3 Msun ≤ 1/50 lower than previously estimated. Thi et al 2010

43. Prospects for Herschel: Disk masses Preliminary results indicate that the disk mass of TW Hya is 0.5 – 5 x 10-3 Msun ≤ 1/50 lower than previously estimated. Thi et al 2010 13CO/12CO(3-2)

44. Inner Disk Holes: Transitional disks “Full” optically thick disk Disk Gaps:Pre-transitional disks Summary Detection of clearing and gaps in optically thick, primordial disks Points to planet formation Suggests evolutionary sequence: Gap opening (pre-TD)  inner disk clearing (TD) Gaps, evidence against inside-out clearing mechanisms: photoevaporation; MRI erosion of wall Many questions remain Herschel: nature of outer disks, different from full? Lower masses? SSC

45. Agent of evolution: planets forming in disk Formed as consequence of dust evolution if core accretion Frederic Masset simulation