Millimeter-Wavelength Observations of Circumstellar Disks and what they can tell us about planets A. Meredith Hughes Miller Fellow, UC Berkeley David Wilner, Sean Andrews, Charlie Qi, Catherine Espaillat, Jonathan Williams, Nuria Calvet, Paola DAlessio, Antonio Hales, Simon Casassus, Michael Meyer, John Carpenter, Michiel Hogerheijde

Star and Planet Formation Overview cloudgrav. collapse protostar + disk + envelope + outflow PMS star + disk MS star + debris disk + planets? Adapted from Shu et al. 1987

Circumstellar Disk Evolution Protoplanetary Pre-MS stars Gas-rich Primordial dust Debris_____ Main sequence No (or very little) gas Dust must be replenished planets? Some Questions: What physical processes shape each stage? What physical processes drive dispersal? When and how do planets form? What are the properties of the planets? AU Mic, Liu et al HH 30, Burrows et al. 1996

F Circumstellar Disk Structure stardisk Why Millimeter Interferometry? Optically thin dust emission Molecular line emission High spatial resolution HD , Grady et al. (2000) Adapted from Dullemond et al. (2007) Low star/disk contrast

2. Resolving Debris Disk Structure The Birds-Eye View 1. Disk Dissipation Constraining physical mechanism(s) driving dissipation Imaging Inner Holes Molecular Gas Content How debris disks can tell us about planets Finding Uranus/Neptune analogues Edge-on debris Masses of directly-imaged planets

What Im NOT going to talk about 0. Protoplanetary Disks as Accretion Disks Observable signatures of viscous transport processes: Magnetic fields (polarization) Turbulence (HiRes spectroscopy) Large-scale structure (But you should ask me about it if youre interested!)

1. Disk Dissipation

Identifying Transition Disks: SED Modeling log log F star dust log log F dust star mid-IR deficit Normal star + disk SED Transitional SED Equilibrium temperature: + Wien Law:

10x less CO than expected Also true for other transition disks in literature (GM Aur, TW Hya) Modeling Transition Disks in CrA Inner holes everywhere? ~ 10% of low- and intermediate- mass stars have transitional SEDs (e.g. Muzerolle, Cieza, Uzpen et al.) Why the ? Boss & Yorke 1996 …we remain skeptical of the existence of such a large central gap devoid of dust -- Chiang & Goldreich (1999) Hughes et al. (2010)

Stellar photosphere Inner disk Wall Outer disk Calvet et al. (2002) TW Hya GM Aur Calvet et al. (2002) Zooming in on the mid-IR… Calvet et al. (2005) Spectral type K7 (Rucinski & Krautter 1983) Age ~ 10 Myr (Webb et al. 1999) Distance 51 pc (Mamajek 2005) Spectral type K5 Age ~ 1-5 Myr (Gullbring+ 1998) Distance 140 pc (Bertout & Genova 2006) Weinberger et al. (2002) Schneider et al. (2003) Predicted inner hole size: 4 AU Predicted inner hole size: 24 AU Testing the paradigm: SED deficit = inner hole

TW Hya GM Aur Calvet et al. (2002) Calvet et al. (2005) Observations Hughes et al. (2007) Hughes et al. (2009b)

Observations Courtesy J. Williams (PIs Andrews, Brown, Cieza, Hughes, Isella, Mathews, Pietu)

Origin of the inner hole? Similar for TW Hya Accretion: Taurus median Gullbring et al No cold CO Dutrey et al Hot CO at 0.5 AU Salyk et al Small amt of hot dust Calvet et al Cavity is not empty!

Dullemond & Dominik (2005) Ireland & Kraus (2008) - in disk center - Dynamical mass + photometry - Keck AO imaging (<40 M jup ) - Hot CO, accretion rate Alexander, Clarke & Pringle (2006) Chiang & Murray-Clay (2007) Origin of the inner hole? Theory:ConsistentInconsistent - in disk center - Lack of cold CO - Sharp transition b/w inner/outer disk - in disk center - Massive outer disk - High accretion rate - in disk center - m-size grains in - Massive outer disk inner disk - Lack of cold CO - Origin of gap? - High accretion rate - Accretion rate - Mass/distance? - Small grains in inner disk -Sharp inner/outer disk transition 4) Binarity e.g. Ireland & Kraus (2008) 5) Planet-Disk Interaction e.g. Lin & Papaloizou (1986), Bryden et al (1999), Varniere et al. (2006), Lubow & DAngelo (2006) 3) Inside-out MRI Clearing Chiang & Murray-Clay (2007) 2) Photoevaporation e.g. Clarke et al. 2001, Alexander & Armitage (2007) 1) Grain Growth ( ) e.g. Strom et al. (1989), Dullemond & Dominik (2005) Bryden et al (1999)

The Plane Najita et al. (2007) Alexander et al. (2007) courtesy S. Andrews photoevaporation binaries planets grain growth

Andrews et al. (2010) Whats next? What will ALMA do? 1. Solve all of science 2. Sensitivity: Finding transition disks Statistics - planet populations Molecular gas evolution 3. Resolution: Measuring accurate cavity sizes Gaps 4. Sensitivity + Resolution: Planetary accretion luminosity Gas in the cavity log log F dust star Pre-Transitional SED Wolf & DAngelo (2005)

2. Resolving Debris Disk Structure

Debris Disks Fomalhaut Kalas et al. (2005) Weinberger et al. (1999) Pic Fitzgerald et al. (2007) HR 4796A Schneider et al. (1999)

Debris Disks If debris disks were primordial, they wouldnt be there dust 10 Myr Debris disks look different at different wavelengths 70 m; Su et al. (2005) 350 m; Marsh et al. (2006)850 m; Holland et al. (2006) At least 15% of nearby main-sequence stars have debris disks (Habing et al. 2001, Rieke et al. 2005, Trilling et al. 2008, Hillenbrand et al. 2008)

How Debris Disks Tell Us about Planets 1. Access to otherwise unobservable Uranus/Neptune analogues Courtesy M. Wyatt Wilner et al. (2002)

How Debris Disks Tell Us about Planets 1. Access to otherwise unobservable Uranus/Neptune analogues Hughes et al. (in prep) Corder et al. (2009) CARMA 230 GHz HD

How Debris Disks Tell Us about Planets 2. Vertical structure of edge-on debris disks From Thebault et al. (2009) Wilner et al. (in prep)

How Debris Disks Tell Us about Planets 3. Constraints on the masses of directly-imaged planets Chiang et al. (2009) Kalas et al. (2008)

How Debris Disks Tell Us about Planets 3. Constraints on the masses of directly-imaged planets Hughes et al. (in prep)

Whats next? What will ALMA do? (Some) debris disks will be roughly as easy to image as protoplanetary disks are now Statistics - planet populations Excellent linear resolution (Molecular gas?)

Summary IR Deficit mm flux cavity 1. Disk Dissipation Calvet et al. (2005) Most transition disks probably cleared by planets Bryden et al (1999) 2. Resolving Debris Disk Structure Access to otherwise unobservable Uranus analogues Edge-on systems Constraining planet masses Molecular gas?