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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).
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The Lifetime ofDust DisksLynne Hillenbrand. . . . . . . . . . . Caltech
10 105 yr Disk/wind Lstar 104 yr Planet building 107 yr 109 yr 1 Planetary system 100 AU Main sequence Cloud collapse 8,000 5,000 2,000 Tstar (K) Star and planet formation/evolution [Beckwith & Sargent 1996]
[04302+2247] Before/during/afterprotostellar collapse [B68] [Padgett et al.] [ONC “proplyd”] [Alves, Lada, Lada] [McCaughrean et al.; Stauffer et al.]
What is the difference between “primordial” and “debris” disks? Debris Primordial [Dullemond and Pontoppidian]
POST ACCRETION ice giant formation DEBRIS DIKS Spitzer legacy science:The formation and evolution of planetary systems 3 Myr – 3 Gyr • 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.
Evolution of our own dust disk in time [D. Backman] Model spectral energy distribution Is our solar system common or u n i q u e ?
NIR MID FIR sub-m Circumstellar disk and SED In anobserved SED, each wavelength traces a distinct temperature, and different temperatures correspond to different radii in disk (cooler at larger radii). 0.1 1.0 10.0 – 40.0 100 AU Temperature 1 10 100
NIR – MID Young (< 30 Myr) disks 0.1 – <1.0 AU A Spitzer instrument to detect these disks: IRAC(3.6 m, 4.5 m, 8.0 m)
MIR FIR Warm disks 10.0 – 40.0 A Spitzer instrument to detect these disks:IRS(10 – 35 m)
FIR Cold outer disks ~20 – 100 AU A Spitzer Instrument to detect these disks:MIPS(24 – 160 m)
Constraints on planet-formation time scalesInner 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.