Stockholm Observatory GENIE - workshop: Leiden, 3-6 June 2002 page 1 T Tauri and Debris Disks Rene´...

GENIE - workshop: Leiden, 3-6 June 2002 page 1Stockholm Observatory

T Tauri and Debris Disks

Rene´ Liseau

Stockholm Observatory, Sweden

[email protected]


T Tauri and Debris Disks

Recent excellent reviews include:

Protostars & Planets IV, Mannings, Boss & Russell eds.

B. Zuckerman, ARAA 2001, 39: 549

W-F Thi 2002, PhD thesis, Leiden

G-J van Zadelhoff 2002, PhD thesis, Leiden


Disks in Time

P.S. Laplace 1796, 1799

Exposition du systeme du mondeMechanique celeste

I. Kant 1755

Allgemeine Naturgeschichte und Theorie des Himmels


Disks in Time

JE Keeler 1895

ApJ 1: 416


Disks in Time

T Tauri Disks: around young stars (0.1 - 10 Myr) of half a solar mass (0.1 - 1 Msun) at 150 pc distance (50 - 450 pc) in and/or near molecular clouds ``accretion disks´´

Debris Disks: around young MS-stars (10 - 400 Myr) of about a solar mass (1 - 2 Msun) at 20 pc distance (3 - 70 pc) in the general field ``Vega-excess stellar disks`´

IRAS 1983 ISO 1995 HST 1993


Frequency of Disks

High Rate of occurence around young stars

NGC 2024 86% Trapezium cluster 80% IC 348 65% Haisch et al. 2001

BDs in Trapezium cluster 65% Muench et al. 2001


Disk Images


HH 30 in L 1551

(Taurus)

T Tauri Disk with Jet


T Tauri Disks - Sizes

R=7000 AU

Fridlund et al. 2002 (mm line data - single dish)White et al. 2000 (mid- & far IR line + cont. - ISO)

L 1551 IRS5outflow source


T Tauri Disks - SizesSize scale (AU) Tracer (mode) Reference

20000 CS (1- 0) (S) Kaifu et al. 19845000 - 10000 13CO (1- 0) (S) Fridlund et al. 1989 1400 C18O (1- 0) (I) Sargent et al. 1988 <500 1.4 mm (I) Woody et al. 1989 45 + 1600 mm, cm (I) Keene & Masson 1990 200 0.8 mm (I) Lay et al. 1994 7000 H13CO+ (1- 0) (S) Mizuno et al. 1994 5000 0.7 - 1 mm (S) Ladd et al. 1995 4000 - 6000 C18, 17O (2- 1) (S) Fuller et al. 1995 1200 13CO (1- 0) (I) Ohashi et al. 1996 4000 H13CO+ (1- 0) (I) Saito et al. 1996 5000 H12, 13CO+ (1- 0) (S, I) Hogerheijde et al.1997, 98 2500 C18O+ (1- 0) (I) Momose et al. 1998

Fridlund et al. 2002

Size depends on frequency/mode of observation


T Tauri Disks - Sizes

Two Disks: separation = 40 AU & R = 5 AU

Rodriguez et al. 1998 (7 mm cont. - VLA Interferometer )L 1551 IRS5

outflow source


T Tauri Disks - SizesSummarising:

T Tauri/HABE disks

50 - 100 AU Dust: mm-continuum interferometry

100 - 300 AU Dust: scattered stellar light

300 AU Gas: CO lines (evidence for Kepler rotation)

Silhouettte disks (``proplyds´´)

up to 1000 AU Dust: scattered stellar light


T Tauri Disks - Sizes & Masses


T Tauri Disks - Masses

Lower limit: 0.001 to 1 MSun (mm/submm continuum)

How good are these numbers?

Do we understand disks?


T Tauri Disks - MassesAssume optically thin emission at long wavelengths (mm+)

monochromatic flux F ~ T

spherical dust grains in equilibrium with stellar radiation achieve

T(a, R) = (h/k) p1/(4+) (L/a R2)1/(4+) Qabs()/a = Q0

p = (Qvis/Q0) c2/(322 h (3+)! m m–(4+) )

i.e. T ~ R-2/(4+)

= 0 => T ~ R-0.50

= 1 => T ~ R-0.40

= 2 => T ~ R-0.33

~



parameters 0 and require knowledge of grain

chemical composition

shape

size

size distribution

... but a good diagnostic? Larsson et al. 2000, 2002 White et al. 2000



Beckwith et al. 2000

Opacities

Gas-to-dust 100?


T Tauri Disks - Structure

Lynden-Bell & Pringle 1974



D´Alessio et al. 1999

40 SEDs


T Tauri Disks - StructureSteady Disks around Single Stars

ESO-AO Brandeker et al. 2001

VW Cha: tidally truncated disk: 60 AU


T Tauri Disks - StructureSteady Disks around Single Stars

Boundary Conditions in : boundary layer, magnetosphereout: ?, interstellar turbulence?

Viscosity MHD/rotation Hawley & Balbus 1995

Opacity , T,...)

Models: Adams & Shu 1986 (flat)Kenyon & Hartmann 1987 (flared)Malbet & Bertout 1991 (vertical structure)D´Allessio et al. 1998,... 2001Aikawa & Herbst 1998 (chemistry)Nomura 2002 (2D)


T Tauri Disks - Make up

T Tauri disks consist of gas and dust

what components?in what proportions?


T Tauri Disks - Make up

van Zadelhoff 2002

13CO (1)

HCO+ (5)

HCN (5)

CO (200)

HCO+ (200)

HCN (200)

LkCa 15 TW Hya


T Tauri Disks - ChemistryMolecular abundances (rel. H2)

Species LkCa 15 TW Hya

CO 3.4(-7) 5.7(-8)HCO+ 5.6(-12) 2.2(-11)H13CO+ <2.6(-12) 3.6(-13)DCO+ …. 7.8(-13)CN 2.4(-10) 1.2(-10)HCN 3.1(-11) 1.6(-11)H13CN …. <8.4(-13)HNC …. <2.6(-12)DCN …. <7.1(-14)CS 8.5(-11) ….H2CO 4.1(-11) <7.1(-13)CH3OH <3.7(-10) <1.9(-11)N2H+ <2.3(-11) <1.8(-11)H2D+ <1.5(-11) <7.8(-12)

Thi 2002


T Tauri Disks - Evolution

Time scales (viscous accretion disk)

tdyn ~ ttherm ~ (H/R)2 tvisc

tdyn ~ 1/Kepler and ~ 10-3 - 10-2


T Tauri Disks - Evolution

Disk dispersal and disk lifetimes

Physical MechanismsHollenbach et al. 2000


T Tauri Disks - EvolutionDisk dispersal and disk lifetimes

Mass accretion evolutionCalvet et al. 2000


T Tauri Disks to Debris Disks

Spangler et al. 2001

fd = LIR/L vs stellar age


T Tauri Disks to Debris Disks

Spangler et al. 2001


Debris Disks - Images

P. Kalas


Debris Disks - Properties

debris (collision products) or particulate (gas free)

percentage of Main Sequence stars (15%?)(observationally) biased towards Spectral Type Afor (detectable) ages <400 Myr Habing et al. 1999, 2001

disk sizes 100 to 1000 AUdisk masses >1 to 100 MMoon (small dust)

Pre-IRASSolar system Zodi US Navy Chaplain G. Jones 1855 AJ 4, 94

Vega Blackwell et al. 1983


THE Debris Disk – PictorisSp. Type A5 V Hipparcos Input Catalogue 1992

Distance 19.3(0.2)pcHipparcos Catalogue 1997

Age 15(5) Myr Song et al. 2001

Metallicity solar Holweger & Rentzsch-Holm 1995

Disk size 1835 AU NE1450 AU SW Larwood & Kalas 2001

Disk Mass dust: >0.44 MEarth Chini et al. 1991

gas: see below


Pictoris

New:

gas disk extension

to >300 AU

in e.g. Na I D2

Olofsson et al. 2001

model modelobser-vation

VLT 2002 =>


Pic Disk Model: GasBest fit model (self consistent photoionisation calculation) to EMMI data with observed emission line flux Na D2 1.5 10-13 erg s-1 cm-2

line rel. flux(line/Na D)

[C I] 370m 3 10-7

[C I] 609m 2 10-7

[C II] 157m 1 10-2 dominates the cooling[O I] 63m 2 10-3

[Si II] 35m 1 10-3

[Fe II] 26m 6 10-5

cf also Kamp & van Zadelhoff 2001, van Zadelhoff 2002


THE Debris Disk – Pictoris

Presence of substantial amounts of H2 debated Thi 2002

Presence of atomic gas – no doubt Olofsson et al. 2001

new VLT data reveal

disk flaring

in e.g. CaII HK

and...slit height 8´´



The VLT Disk Spectrum (340 – 390 nm)

only permitted lines

no Fe II, no H I

Fe I multiplets 4, 5, 40, 41

Ca II H & K

Tbc Ni I, Ti I, V II, Cr I, Co I, Mn I, Ru I, Ce II, Tm I



1200 m (SEST)

850 m (JCMT)

...and the

``Blob´´


THE Debris Disk – PictorisSCUBA JCMT 850m SIMBA SEST 1200m Holland et al. 1998

Peak position +0.8, +0.7 arcsec (?) 0, 0Peak flux 58.3(6.5) mJy/beam 24.3(2.5) mJy/beam

Deconvolved size 22´´ x 11´´ 26´´ x 10´´

Blob position -21, -26 arcsec -26, -44 arcsec

Position angle 39.6 deg 31.5 deg

Distance 34´´ 52´´Flux 19.1(6.5) mJy/beam 9.7(2.3) mJy/beam

Ratio 3.0(1.1) 2.50(0.65)


Debris Disks and PlanetsDisks have non-homogeneous structure – not simple power law distributions

because of planet(s)?

PicKeck 18 m Wahhej et al. 2002

Heap et al. 2000


Debris Disks and PlanetsDisks have non-homogeneous structure – not simple power law distributions

because of planet(s)?

Wilner et al. 2002

Lyr

1.3 mm

(PdB)

Model:

excentric ``Jupiter´´


Debris Disks and Planets

Do ``Planet-Stars´´ have disks?

55 Cnc No! Jayawardhana et al. 2002

CrB tbc Trilling et al. 2000

HD 210277 tbc

Eri

a

border case?

Hatzes et al. 2000


Disks: Open QuestionsGrain growth: from micron to cm size

from cm to 100 m+ size

Time of (giant) planet formation

termination of planet migration

Processes/time scales of disk dispersal

formation and evolution of debris disks

Role of stellar multiplicity

free-floating planets


Disks and GENIE Angular resolution of order 2.5 (m)/b100m mas

Debris disks generally at > 25 m Laureijs et al. 2002

L-band (1000 K), N-band (300 K)

L-band: min(scat, abs)T Tauri disk: 0.4 AU 3 mas Debris disk: 1.2 AU 60 mas

N-band: hot telescope/skyT Tauri disk: 9 AU 60 masDebris disk: 25 AU 1.2 arcsec

Stockholm Observatory GENIE - workshop: Leiden, 3-6 June 2002 page 1 T Tauri and Debris Disks Rene´...

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Transcript of Stockholm Observatory GENIE - workshop: Leiden, 3-6 June 2002 page 1 T Tauri and Debris Disks Rene´...