1. 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

2. 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

3. 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

4. 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

5. 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: microns
20 microns

6. Disseminate results Planetary Data System, Cross-referenced
Curation of all samples at AMNH
Samples
Pellets
All data

7. 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

8. Hydroxyl-containing, acid- and hydrated Carbonates:
Spitzer
PACS
Spitzer
PACS

9. Phyllosilicates (micas)
PACS

10. Feldspars Spitzer Spitzer PACS PACS both Plagioclase-
(Albite-Anorthite)
and
Alkali-
(Albite-Orthoclase)
solid solution series
were examined

11. Sulfides:
PACS

12. The effect of smaller particle size:
The increase of mass absorption coefficient values for the samples with
smaller mean particle size

13. Temperature dependence
Icy dust

14. 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

15. 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

16. 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