the lifetime of dust disks lynne hillenbrand . . . . . . . . . . . caltech
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The Lifetime of Dust Disks Lynne Hillenbrand . . . . . . . . . . . Caltech. 10. 10 5 yr. Disk/wind. L star. 10 4 yr. Planet building. 10 7 yr. 10 9 yr. 1. Planetary system. 100 AU. Main sequence. Cloud collapse. 8,000. 5,000. 2,000. T star (K). - PowerPoint PPT PresentationTRANSCRIPT
The Lifetime of
Dust Disks
Lynne Hillenbrand. . . . . . . . . . .
Caltech
Star and planet formation/evolution
Cloud collapse
104 yr
Planetary system
109 yr
105 yr
100 AU
107 yr
Tstar (K)
Lstar
Main sequence
8,000 5,000
10
1
2,000
Disk/wind
Planet building
[Beckwith & Sargent 1996]
Before/during/afterprotostellar collapse
[Alves, Lada, Lada]
[B68]
[Padgett et al.]
[McCaughrean et al.; Stauffer et al.]
[04302+2247]
[ONC “proplyd”]
Not so much later: Debris disks
What is the difference between “primordial” and “debris” disks?
Primordial Debris
[Dullemond and Pontoppidian]
Spitzer legacy science:The formation and evolution of planetary systems
• Birth of planetary embryos:
Characterize transition from
primordial to debris dust disks.
• Growth of gas giant planets:
Constrain time scale for gas
disk dissipation.
• Mature solar system evolution:
Examine diversity of planetary
systems based on debris disks.
PO
ST A
CC
RE
TIO
ND
EB
RIS
DIK
S
ice
gian
t for
mat
ion
3 Myr – 3 Gyr
Evolution of our own dust disk in time
Model spectral energy distribution
Is our solar system
common
or
u n i q u e ?
[D. Backman]
Circumstellar disk and SED
In an observed SED, each wavelength traces a distinct temperature, and different temperatures correspond to different radii in disk (cooler at larger radii).
NIR MID FIR sub-m
0.1 1.0 10.0 – 40.0 100 AU
Temperature
1 10 100
Young (< 30 Myr) disks
NIR – MID
0.1 – <1.0 AU
A Spitzer instrument to detect these disks: IRAC (3.6 m, 4.5 m, 8.0 m)
Warm disks
MIR FIR
10.0 – 40.0
A Spitzer instrument to detect these disks: IRS (10 – 35 m)
Cold outer disks
FIR
~20 – 100 AU
A Spitzer Instrument to detectthese disks: MIPS (24 – 160 m)
Constraints on planet-formation time scales
Inner disk dissipationData suggest <3–10 Myr as maximum accretion disk lifetime. Typical lifetime for material at <0.1 AU is <3 Myr.
Mid-disk dissipationMaximum disk lifetime for terrestrial planet material at 1 AU is also <10 Myr. Compare with meteoritic evidence suggesting Earth formed in <10 Myr with moon-forming impact occurring at 30 Myr.
Outer disk dissipation and re-generationPrimordial disk lifetimes as yet unconstrained. Debris disk lifetimes consistent with expectations from self-sustaining collisional cascade.