The carbonaceous chondrites

Mason, Brian

doi:10.1007/bf00212446

Cited by 227 publications

(79 citation statements)

References 35 publications

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“…However, the meteoritic value is only based on the P abundance in the Orgueil meteorite, for which a concentration of 920 AE 100 ppm is derived (mainly from data by Wolf & Palme 2001). The P abundances of other CI chondrites are much more uncertain; for Ivuna, one reliable P analysis of 760 ppm exists (Wolf & Palme 2001), whereas P analyses of other CI chondrites date back several decades to almost a century, and range from 500 to 1800 ppm (see Mason 1963). Because both the photospheric and meteoritic abundances have 10% relative uncertainty, the average of AðPÞ ¼ 5:46 AE 0:04 is adopted as representative for the solar photosphere.…”

Section: Phosphorus Abundancementioning

confidence: 99%

Solar System Abundances and Condensation Temperatures of the Elements

Lodders

2003

ApJ

4,263

227

4,623

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Solar photospheric and meteoritic CI chondrite abundance determinations for all elements are summarized and the best currently available photospheric abundances are selected. The meteoritic and solar abundances of a few elements (e.g., noble gases, beryllium, boron, phosphorous, sulfur) are discussed in detail. The photospheric abundances give mass fractions of hydrogen (X ¼ 0:7491), helium (Y ¼ 0:2377), and heavy elements (Z ¼ 0:0133), leading to Z=X ¼ 0:0177, which is lower than the widely used Z=X ¼ 0:0245 from previous compilations. Recent results from standard solar models considering helium and heavy-element settling imply that photospheric abundances and mass fractions are not equal to protosolar abundances (representative of solar system abundances). Protosolar elemental and isotopic abundances are derived from photospheric abundances by considering settling effects. Derived protosolar mass fractions are X 0 ¼ 0:7110, Y 0 ¼ 0:2741, and Z 0 ¼ 0:0149. The solar system and photospheric abundance tables are used to compute self-consistent sets of condensation temperatures for all elements.

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Section: Phosphorus Abundancementioning

confidence: 99%

Solar System Abundances and Condensation Temperatures of the Elements

Lodders

2003

ApJ

4,263

227

4,623

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“…Since CIRs accelerate particles to modest energies, the bulk of the data reported here were obtained with the Ultra Low Energy Isotope Spectrometer (ULEIS; Mason et al 1998) supplemented above $5 MeV nucleon À1 by observations from the Solar Isotope Spectrometer (SIS; Stone et al 1998b). These instruments achieve a combination of high sensitivity and mass resolution that allows determination of composition and energy spectra to a much higher level of precision than prior studies.…”

Section: Instrumentationmentioning

confidence: 99%

“…Equation (1) is the Fisk & Lee (1980) prediction at the location of the CIR shock; their predicted spectra at 1 AU include an additional factor involving distance to the shock (their eq. [6]), and this additional term becomes very small for particle speeds below $100 keV nucleon À1 (see discussion in Mason et al 1999b). The predicted rollover in the spectrum is not apparent in the data presented here, and observations at even lower energies than those reported here show that CIR spectra continue smoothly as power laws down to solar wind energies (Chotoo et al 2000).…”

Section: Acceleration Mechanisms and Seed Populationmentioning

confidence: 99%

Abundances and Energy Spectra of Corotating Interaction Region Heavy Ions Observed during Solar Cycle 23

Mason

Leske

Desai

et al. 2008

ApJ

103

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Using instruments on the ACE spacecraft, we surveyed the heavy-ion spectra and composition over the range HeFe for 41 corotating interaction regions (CIRs) during 1998-2007. Below $1 MeV nucleon À1 the spectra are power laws in kinetic energy nucleon À1 with an average spectral index of 2:51 AE 0:10, rolling over above $1 MeV nucleon À1 to power-law spectra with an average index of 4:47 AE 0:17. The spectral shapes for different species are similar, leading to relative abundances that are constant over our energy range, even though the intensities cover up to 8 orders of magnitude. Relative to oxygen, the measured abundances at 385 keV nucleon À1 for 4 He, C, N, Ne, Mg, Si, S, Ca, and Fe are 273 AE 72, 0:760 AE 0:023, 0:143 AE 0:005, 0:206 AE 0:009, 0:148 AE 0:006, 0:095 AE 0:005, 0:028 AE 0:002, 0:007 AE 0:001, and 0:088 AE 0:007, respectively. Except for an overabundance of 4 He and Ne, the abundances are quite close to that of the fast solar wind. We have found 3 He/ 4 He ratios to be enhanced over solar wind values in $40% of the CIRs. The Fe/O ratio in individual CIRs is observed to vary over a factor of $10 and is strongly correlated with the solar wind Fe/O ratio measured 2-4 days preceding each CIR. Taken together with previous studies showing the presence of pickup He + in CIRs, the observational data provide evidence that CIR energetic particles are accelerated out of a suprathermal ion pool that includes heated solar wind ions, pickup ions, and remnant suprathermals from impulsive solar energetic particle events.

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“…The BPA structures for the micro density is formed by referring to 11 CM chondrites [34]. The micro porosity is simply assumed to be 15.5-30.5% [30] which is consistent with the work of Flynn et al [35].…”

Section: A12 C-typementioning

confidence: 52%