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

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

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

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

6 Transitional disks Calvet et al 2002 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 ‘s consistent with optically thick emission Strom et al. 1989, inner disk clearings and disks in transition

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 transitional evolved Hernandez et al 2007, 2008, 2010

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

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

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

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

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

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

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

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

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

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 Evolution without photoeva- poration RgRg Clarke et al

Direct and indirect effects of photoevaporation 18 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 ~ M sun /yr to M sun /yr (Owen et al. 2010) Difficult to understand low dM/dt’s Line profiles? Extent of [OI] emission? Gorti’s talk

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

Important in evolved disks Low dM/dt Low disk masses Cieza

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

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

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

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

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 Hughes et al 2009 IRS spectra finely maps disk structure GM Aur Inner regions evacuated of mm-size grains

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

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)  Photoevaporation Transitional disks Alexander & Armitage 2007 Najita, Strom, & Muzerolle 2007 Planet

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

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

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

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

33 Dust-gas Transition Monnier & Millan-Gabet 2002

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

35 Structure of inner disk Disk with gap - Pre-transitional Disk with inner clearing – Transitional Espaillat et al 2010 Umbra Penumbra Height of wall ~ height of disk behind it, as modeled from SED Inner disk shadowing outer wall? Mulders, Dominik, & Min 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 M jup outside14 AU Pericenter offset ~ 9AU, supports dynamical effects due to planets Thalmann et al 2010

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 ≥ M sun /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 37

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

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

Can planets really make pre/transitional disks? Zhu et al 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)

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

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

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

44 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? “Full” optically thick disk Disk Gaps:Pre- transitional disks Inner Disk Holes: Transitional disks SSC

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