1. C.M. Lisse (JHU-Applied Physics Laboratory)
Extending the Results of the Spitzer-Deep Impact Experiment to Other Comets and Exo-Systems
C.M. Lisse (JHU-Applied Physics Laboratory)
(Typical JFC)
T1 Ejecta
(Oort Cloud)
16 um Ejecta Imaging

2. De-aggregation and Ejection of Sub-surface Fresh(?) PSN Material
GMC
ISM
Cometary Dust
Poorly Understood Process of Chemical and Gravitational Aggregation #1, occurring in T ≤ 1 Myr
~1 um
Proto-Solar Nebula
30 um
Ices - C, H, O, N
Dust - Mg, Si, Fe, S
Ca, O, Al, C, …
P.U.P.C.G.A. #2,
occurring in T ≤ 10
Myr
Origin = Solar nebula
Deep
Impact
~5 km
T<400K,
P < 1kPa
De-aggregation and Ejection of
Sub-surface Fresh(?) PSN Material
Icy Dirtball Comet Nucleus

3. Parameters Derivable From the DI Experiment
Bulk, Average Composition of Ejected Dust
Obtained from features at set wavelengths
Allows search for comparable species in other systems
Temperature of Dust Components at 1.5 AU
Obtained from short/long wavelength amplitude, feature
No modeling required
Yields location of dust in exo-systems from observed T’s
Particle Size Distribution of Ejected Dust
Obtained from feature/continuum ratio
Unusual narrowly peaked distribution um

4. (Pre-Post)/Pre = Ejecta/Pre-Impact Coma
Spitzer IRS I+45 Min
344 Spectral Points
SNR (2 error bars)
95% C.L. = 1.13
Simultaneous um
> 16 Sharp Features
Best-Fit Linear
Sum

(95% C.L. = 1.13)
Carbonates (Chalk)
(Pre-Post)/Pre = Ejecta/Pre-Impact Coma
PAHs (Soot, Exhaust)
Water
Gas
Amorphous Carbon (Soot)
Water Ice
Phyllosilicates (Clay)
Sulfides (Fool’s Gold)
Pyroxenes (Rock)
Olivines (Rock)
Lisse et al. 2006

5. Fire, Mud, & Ice : Tempel 1 Contains Xtal Silicates, Annealed at T > 1000K + Carbonates & Clays - Formed via Interaction with Water + Ices - Stable Only Below 200 K
Radial Mixing of PSN Material. From inside the orbit of Mercury to outside the orbit of Neptune (turn-off when giant planet cores form)
Crystal
Silicates
Carbonates
Clays
Comets
Parent Body Aqueous Alteration Over 4.5 Gyr
(1) Impulsive Cratering (2) Long Term Water Vapor Processing

6. SST-IRS P/Tempel 1 Ejecta Difference Spectrum vs
SST-IRS P/Tempel 1 Ejecta Difference Spectrum vs. ISO-SWS C/Hale-Bopp, YSO HD100546
Silicates
YSO with Rich Dusty Disk
Input
PAHs
Formed in Giant Planet Region
Resides in Outer Solar System Today
Output
Sulfides
Carbonates
Formed in Kuiper Belt
Resides in Inner Solar System
Sun

7. SST-IRS P/Tempel 1 Ejecta Spectrum Compared to Comets, Exo-Systems
SST-IRS P/Tempel 1 Ejecta Spectrum Compared to Comets, Exo-Systems. - -Similar Spectra Due to Presence of Silicates, PAHs, Water, Sulfides. - Differences Due to Relative Compositions, T, Particle Size
Comets Hale-Bopp, SW3, SW1
Disk Systems HD100546, HD69830, HD113766
10 Myr Be9V YSO w/ Disk Cavity
~15 Myr F3/F5 YSO
2-10 Gyr K0V w/ 3 Neptunes

8. “Spectral Fingerprints” of Cometary IR Mineralogy
1.47 AU
1.5 AU
JFC SW-3 B
Fragment
(SST; Sitko
et al. 2007)
JFC
Tempel 1
Ejecta
(SST; Lisse
et al. 2006)
Amorph
Carbon
PAHs
Carbonates
Sulfides
Pyroxenes
Olivines
2.8 AU
5.7 AU
JFC/Centaur
SW-1 Coma
(SST;
Stansberry
et al. 2005)
Oort Cloud
Hale-Bopp
Coma (ISO;
Crovisier
et al. 1997))
Carbonates
Water Ice
Pyroxenes
Smectite (clay)
Olivines
Olivines
Lisse et al. 2007
“Spectral Fingerprints” of Cometary IR Mineralogy
T1 Spectral Model applied to other systems fits spectra well, extends results to Spitzer, ISO database. We can now dig down below the dominant silicate emissions to find other species.
Hale-Bopp : No Fe-rich olivine. Much more water ice and amorphous carbon. Carbonates, clay.
SW1, SW3 : Much amorphous silicates, Mg-rich olivine. Only water gas for SW3, ice for SW1.

9. Abundance of Cometary Water Ice vs
Abundance of Cometary Water Ice vs. Gas Follows Water Ice Stability in Solar System
(water ice stable)
(rapidly ejected
Interior material)
(water ice rapidly
sublimating)

10. Silicate Trends? (work in progress)
Relative amount of crystalline pyroxene increases from SW1, SW3 to Tempel 1. Tempel 1 appears most ”processed”. Hale-Bopp probably formed early, but why SW3 so “fresh”? Deep interior material, or bodies formed in PSN at different times 1- 10(?) Myr and places ( AU)?
Silicate Trends? (work in progress)
asteroidal
cometary
Pyroxene content is high
for comets and HD100546,
low for asteroidal debris disks

11. “Mature” HD69830 K0V, T = 5400 K, 2 - 10 Gyr old, 12 pc distant
K0V, 12 pc
K0V, T = 5400 K, Gyr old, 12 pc distant
3 Neptune Sized 0.08, 0.16, 0.63 AU
Lovis et al. 2006 B C D
Asteroidal Dust Belt
Lisse et al. 2007
T~ 400 K
Super Comet or Asteroid?
Carbonates
PAHs absent
Carbon attenuated
Water Ice
Pyrox all crystalline
Sulfides absent
Olivine Super-rich
Lisse et al. 2007
Beichman et al. 2005
“Near-solar” star. Small, icy, ephemeral dust replenished by ongoing fragmentation. S.S. analogue : ~30 km radius P/D asteroid 1 AU. Karins/Veritas 5-8 Mya?

12. Comparative IR Mineralogy of Young Stellar Objects
HD : Comet-like. Especially rich in Mg-rich olivine and amorphous pyroxene, water ice. We find the dust to be at ~13 AU, consistent with the inner disk cavity edge of Grady et al
HD : Mainly has Mg-rich olivine, Fe-rich sulfides, and xtal pyroxene. Little carbonates, clays, PAHs, or amorphous carbon present. Similar to S-type asteroid. NOT an older HD
Amorph
Carbon
HD Disk Herbig Be9V >10 Myr X
PAHs
HD Disk F3/F5 ~16 Myr
Carbonates
Water Ice
Sulfides
Clays
Sulfides
Pyroxenes
Pyroxenes
Olivines
Olivines
Lisse et al. 2007

13. Comets r(AU) Water Ice/Gas Silicates Carbonates Clays PAHs Sulfides
Tempel Ice & O:P = 1 Magnesite & Yes Yes Yes
JFC Gas fxtalo = 0.7 Siderite
(SST, 5-35um) (Impact) fxtalp = 0.9
SW Abundant O:P = 1.6 Some No Yes Yes
JFC Water Gas fxtalo = 0.3 Siderite
(SST, 5-35um) (Near-Sun) fxtalp = 0.6
HaleBopp Abundant O:P = 1.3 Abundant Yes Yes Yes
Oort Cloud Water Ice fxtalo = 0.7 Magnesite &
(ISO, 5-40um) (Beyond Ice fxtalp = 0.7 Siderite
Line)
SW Abundant O:P ~ 3.2 Some No Yes? Some
Centaur/JFC Ice (BYI) fxtalo = 0.3 Siderite
(SST, 7-35um) fxtalp = 0.5
Exo-systems r(AU) Water Ice/Gas Silicates Carbonates Clays PAHs Sulfides
HD ~13 AU Abundant O:P = 0.8 Magnesite Yes YES Yes
Be9V, ≥ 10 My (103pc) Ice & Water fxtalo = 1.0
(ISO, 5-40um) fxtalp = 0.3
HD ~1.8 AU Some O:P = 2.4 None ~None No Yes
F3/F5, ~16 My (131pc) Ice fxtalo = 0.7
(SST, 5-35um) fxtalp = 1.0
HD ~1 AU Some O:P = 2.8 ??? None No? No
K0V, Gy (12pc) Ice fxtal = 0.8
(SST, 7-35um) fxtalp = 0.8

14. Conclusions
We have obtained good fits to the um mid-IR spectra of comets HaleBopp, SW3, and SW1 using the Deep-Impact -T1 ejecta model.
Silicates, PAHs, water, and sulfides are found in abundance in all studied systems.
We find the water content of the comets is gaseous inside the ice line, solid outside it, following the solid ice stability in the solar system.
The relative amount of pyroxene decreases as the systems become processed into asteroidal material. In the comets, crystal pyroxene may increase with time of formation.
We find emission from HD69830 (K0V, 2-10 Gy, ~0.5 Lsolar) dominated by highly processed dust from disruption of a ~ 30 km P or D-type body.
We find emission from HD (Be9V, > 10 My, Lsolar) dominated by primitive nebular material at ~13 AU, at the disk inner cavity wall of Grady et al.
We find emission from HD (F3/F5, ~15 My, 4.4 Lsolar) dominated by processed dust from disruption of an ~S-type, terrestrial planet forming?) body at 2.2 AU.
=> Disks can be either primordial nebulae (cometary?) or due to stochastic collisions of coherent small bodies (asteroidal?).