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Presented at AAS meeting, Washington DC Jan 2010. Laboratory Spectroscopy in Herschel/PACS Range of Astrophysically Important Minerals. Tatiana Brusentsova, Doug Maukonen, Pedro Figueiredo, Himanshu Saxena, Robert E. Peale. Andy Nissinboim, Joseph Boesenberg, Julie Leibold, Kristen Sherman
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Presented at AAS meeting, Washington DC Jan 2010 Laboratory Spectroscopy in Herschel/PACS Range of Astrophysically Important Minerals Tatiana Brusentsova, Doug Maukonen, Pedro Figueiredo, Himanshu Saxena, Robert E. Peale Andy Nissinboim, Joseph Boesenberg, Julie Leibold, Kristen Sherman George E. Harlow , Denton Ebel Karl Hibbitts and Carey Lisse
Astro-relevant minerals high-T (>1000K) predictions from condensation calculations minerals found in carbonaceous chondrite meteorites minerals interpreted from Spitzer/Deep Impact spectrum, found in Stardust samples and in IDPs minerals found in differentiated meteorites and planets minerals reported in astronomical spectroscopy
Lab measurements support PACS data analysis Thermal emission: 4 p c k(w) e0(w) dw • e0(w) = Planck function • k = (S/m) ln (1/T) = mass absorption coef. • S = sample cross-section • m = mass in sample • T = transmittance spectrum
Physical Characterization Select grains from AMNH mineral collection • Crush to separate intergrowths • Sweep magnetic impurities • Dissolve carbonate impurities in HCl (acid) • Hand pick clean grains Verify crystallography (single crystal x-ray) Electron microprobe on single grains • Chemical composition • Cation stoichiometry
Pellet preparation and spectroscopy cerussite Make dust • micronizing mill • Stokes settling • grain size distribution Weigh and mix in polyethylene powder Melt press to pellets Fourier transform spectrometer: 14-250 microns 20 microns
Disseminate results • Planetary Data System, Cross-referenced • Curation of all samples at AMNH • Samples • Pellets • All data
Carbonates: Calcite & Dolomite group Spitzer PACS Spitzer PACS • The lines in the PACS • range within the same • mineral group directly • depend on the mineral • species
Hydroxyl-containing, acid- and hydrated Carbonates: Spitzer PACS Spitzer PACS
Spitzer Spitzer PACS PACS Feldspars both Plagioclase- (Albite-Anorthite) and Alkali- (Albite-Orthoclase) solid solution series were examined
Sulfides: PACS
The effect of smaller particle size: • The increase of mass absorption coefficient values for the samples with • smaller mean particle size
Temperature dependence Icy dust
150 Minerals Sampled • Nesosilicates: Olivines, Garnets, Phenakites • Silica minerals • Inosilicates: Pyroxenes (Clino- and Ortho-), “Pyroxenoids” • Feldspars: Alkali and Plagioclase • Double-chain silicates: Amphiboles (Orthorhombic, Calcic clino-) • Cyclosilicates • Carbonates: Calcites, Aragonites, Dolomites, hydroxylated, Hydrated-normal, acid • Phyllosilicates: Smectites, Chlorites, Micas, Kaolinites, Serpentines, Talcs • Sorosilicates • Oxides • Sulfides
Applications • Early PACS report: 69 mm feature “due to olivine.” True? We find no olivine feature there. • Simulation of dust emission spectrum Linear superposition of absorbance for (e.g.) 38% water ice, 22% forsterite, 22% orthopyroxene (Mg-rich end member), 8% pyrrohtite, 5% talc or nontronite, 2.5% magnesite, and 2.5% siderite
Summary • Laboratory far-IR absorption spectroscopy of 150 well-characterized minerals • Spectral signatures found in the range of Herschel-PACS for 40 • No features ever found beyond ~140 mm • Funding: NASA-JPL