1 / 22

T1 Ejecta

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. GMC. ISM. Cometary Dust. ~1 um.

kordell
Download Presentation

T1 Ejecta

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 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. GMC ISM Cometary Dust ~1 um Poorly Understood Process of Chemical and Gravitational Aggregation #1, occurring in T ≤ 1 Myr 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 Deep Impact ~5 km T<400K, P < 1kPa De-aggregation and Ejection of Sub-surface Fresh(?) PSN Material Icy Dirtball Comet Nucleus

  3. Spitzer IRS I+45 Min 344 Spectral Points SNR 5 - 30 (2 error bars) 95% C.L. = 1.13 Simultaneous 5- 35 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 Sulfides (Fool’s Gold) Phyllosilicates (Clay) Pyroxenes (Rock) Olivines (Rock) Lisse et al. 2006

  4. 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

  5. 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 Disk Systems HD100546, HD69830, HD113766 Comets Hale-Bopp, SW3, SW1 10 Myr Be9V YSO w/ Disk Cavity ~15 Myr F3/F5 YSO 2-10 Gyr K0V w/ 3 Neptunes

  6. 1.47 AU 1.5 AU JFC Tempel 1 Ejecta (SST; Lisse et al. 2006) JFC SW-3 B Fragment (SST; Sitko et al. 2007) 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 Smectite (clay) Pyroxenes 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.

  7. 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)

  8. 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 (4 - 50 AU)? Silicate Trends?(work in progress) asteroidal cometary Pyroxene content is high for comets and HD100546, low for asteroidal debris disks

  9. K0V, 12 pc • K0V, T = 5400 K, 2 - 10 Gyr old, 12 pc distant • 3 Neptune Sized Planets @ 0.08, 0.16, 0.63 AU Lovis et al. 2006 “Mature” HD69830 B C D Asteroidal Dust Belt Lisse et al. 2007 T~ 400 K Super Comet or Asteroid? Carbonates PAHs absent Carbon attenuated Water Ice Sulfides absent Pyrox all crystalline 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 disrupted @ 1 AU. Karins/Veritas 5-8 Mya?

  10. Comparative IR Mineralogy of Young Stellar Objects HD100546 : 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. 2005. HD113766: 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 HD100546. Amorph Carbon HD100546 Disk Herbig Be9V >10 Myr X PAHs HD113766 Disk F3/F5 ~16 Myr Carbonates Water Ice Sulfides Clays Sulfides Pyroxenes Pyroxenes Olivines Olivines Lisse et al. 2007

  11. Conclusions • We have obtained good fits to the 5- 35 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 HD100546 (Be9V, > 10 My, 22-26 Lsolar) dominated by primitive nebular material at ~13 AU, at the disk inner cavity wall of Grady et al. • We find emission from HD113766 (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?).

  12. 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 0.1 - 10 um

  13. Comets r(AU) Water Ice/Gas Silicates Carbonates Clays PAHs Sulfides Tempel 1 1.51 Ice & O:P = 1 Magnesite & Yes Yes Yes JFC Gas fxtalo = 0.7 Siderite (SST, 5-35um) (Impact) fxtalp = 0.9 SW3 1.47 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 2.8 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) SW1 5.8 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 HD100546 ~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 HD113766 ~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 HD69830 ~1 AU Some O:P = 2.8 ??? None No? No K0V, 2 - 10 Gy (12pc) Ice fxtal = 0.8 (SST, 7-35um) fxtalp = 0.8

  14. Wild 2-like Areas? Impact Potential Reasons for Deep Impact/STARDUST Differences in Carbonate, Phyllosilicate Mineralogy Raised Layers R.L. Depression • Cometary Diversity - Differences in Formation Time, Location, Evolutionary History (e.g. Tempel 1 rather processed and old, Wild2 rather young) • Aqueous Alteration at the one DI Location sampled in depth • Modelling Errors in Studyng the DI-Spitzer Data - CaO/CaOH? CH4.C2, C3? • Stardust Small # Statistics to Date, Aerogel Obscuration • Cold Excavation (DI) vs. Hot Aerogel Capture (STARDUST) • Differences in surface vs. interior material - DI burrowed through a surface mantle layer to different material underneath. Carbonates known to be UV photodissociated.

  15. Good Evidence Much of the Original ISM Material Has Been Reworked(ISM = amorphous silicates, abundant PAHs).(2) Expected PSN Species from the Equilibrium Condensation Sequence : - Metal (Al, Mg, Ti) Oxides- Olivines- Pyroxenes- Fe/Ni metal- (Na,K) Feldspars- Fe Sulfides- Phylosilicates(after Lewis, 1995)

  16. Atomic Abundances2s error bars for the relative measures are ± 20%. Diamonds = Tempel 1, Triangles = Hale-Bopp, Squares = HD100546.

  17. Tempel 1 Best Fit Model Atom Abundances Are Consistent with Solar for the Refractory Elements H : C : O : Si : Mg : Fe : S : Ca : Al 0.42 : 0.58 : 3.9 : 1.0 : 0.88 : 0.79 : 0.29 : 0.054 : ≤ 0.085 [x 106] (H, C, O Depleted, Mostly in Volatiles) Orgueil CI Meteorite Sun

  18. Spitzer IRS I+45 Min Sulfides Carbonates Ejecta Emissivity - Silicate BestFit Model Amorph Carbon Water Ice Water Gas PAHs Lisse et al. 2006

  19. Wild 2-like Areas? Impact Carbonates • YSO : 1/2 of all ISO spectra • Ceccarelli et al. 2002 • Chiavassa et al. 2005 Raised Layers R.L. Depression Non-DI Measures in Comets/IDPs • Bregmann et al. 1987 Halley IR • Clark et al (1987) Halley in situ (PIA, PUMA) • Sanford et al. 1984, 1986 IDP chemistry, crystallography • Potential Reasons for DI/SD Diff • Cometary Diversity • Aqueous Alteration at (1) DI Location • Modelling Errors - CaO/CaOH? • Stardust Small # Statistics • Cold Excavation vs. Hot Aerogelç

  20. Tempel 1 Bulk Ejecta Temperatures Implications: folivine ~ fpyroxene; Oliv Mg-rich, 70% xtal, Pyrx Fe/Ca-rich, 90% xtal; 8% Phyllosilicates; 5% Carbonates Mg-Fe rich, not Ca; PAHs at 1000 ppm; S bound in Fe-rich sulfides; H2O ice at 4% level; abundant amorphous C <-----SD Compliant------> ???

  21. 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

More Related