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| 2. |
- Ming, D.W., et al.
(författare)
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Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale Crater, Mars
- 2014
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 343:6169
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Tidskriftsartikel (refereegranskat)abstract
- H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.
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| 3. |
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| 4. |
- Balland, C., et al.
(författare)
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The ESO/VLT 3rd year Type Ia supernova data set from the supernova legacy survey
- 2009
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 507:1, s. 85-103
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Tidskriftsartikel (refereegranskat)abstract
- Aims. We present 139 spectra of 124 Type Ia supernovae (SNe Ia) that were observed at the ESO/VLT during the first three years of the Canada-France-Hawa Telescope (CFHT) supernova legacy survey (SNLS). This homogeneous data set is used to test for redshift evolution of SN Ia spectra, and will be used in the SNLS 3rd year cosmological analyses. Methods. Spectra have been reduced and extracted with a dedicated pipeline that uses photometric information from deep CFHT legacy survey (CFHT-LS) reference images to trace, at sub-pixel accuracy, the position of the supernova on the spectrogram as a function of wavelength. It also separates the supernova and its host light in similar to 60% of cases. The identification of the supernova candidates is performed using a spectrophotometric SN Ia model. Results. A total of 124 SNe Ia, roughly 50% of the overall SNLS spectroscopic sample, have been identified using the ESO/VLT during the first three years of the survey. Their redshifts range from z = 0.149 to z = 1.031. The average redshift of the sample is z = 0.63 +/- 0.02. This constitutes the largest SN Ia spectral set to date in this redshift range. The spectra are presented along with their best-fit spectral SN Ia model and a host model where relevant. In the latter case, a host subtracted spectrum is also presented. We produce average spectra for pre-maximum, maximum and post-maximum epochs for both z < 0.5 and z >= 0.5 SNe Ia. We find that z < 0.5 spectra have deeper intermediate mass element absorptions than z = 0.5 spectra. The differences with redshift are consistent with the selection of brighter and bluer supernovae at higher redshift.
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| 5. |
- Moore, F. R., et al.
(författare)
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Cross-cultural variation in women's preferences for cues to sex- and stress-hormones in the male face
- 2013
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Ingår i: Biology letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- Women in the UK prefer the faces of men with low levels of the stress hormone cortisol, and the relationship is moderated by the sex hormone testosterone. In a Latvian sample, however, women's preferences were not affected by cortisol, and the interaction with testosterone differed from that of the UK. To further explore cross-cultural variation in preferences for facial cues to sex- and stress-hormones, we tested the preferences of women from 13 countries for facial composites constructed to differ in combinations of the hormones. We found significant relationships between a measure of societal development (the United Nations human development index 2011) and preferences for cues to testosterone in the face, and the interaction between preferences for cues to testosterone and cortisol. We also found a significant relationship between preferences for cues to testosterone and a societal-level measure of parasite stress. We conclude that societal-level ecological factors influence the relative value of traits revealed by combinations of sex- and stress-hormones.
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| 6. |
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| 7. |
- Stolper, E.M., et al.
(författare)
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The petrochemistry of Jake_M : A martian mugearite
- 2013
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 341:6153
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Tidskriftsartikel (refereegranskat)abstract
- “Jake_M,” the first rock analyzed by the Alpha Particle X-ray Spectrometer instrument on the Curiosity rover, differs substantially in chemical composition from other known martian igneous rocks: It is alkaline (>15% normative nepheline) and relatively fractionated. Jake_M is compositionally similar to terrestrial mugearites, a rock type typically found at ocean islands and continental rifts. By analogy with these comparable terrestrial rocks, Jake_M could have been produced by extensive fractional crystallization of a primary alkaline or transitional magma at elevated pressure, with or without elevated water contents. The discovery of Jake_M suggests that alkaline magmas may be more abundant on Mars than on Earth and that Curiosity could encounter even more fractionated alkaline rocks (for example, phonolites and trachytes).
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| 8. |
- Urquiza-González, M., et al.
(författare)
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Benchmark evaluation for a single frequency continuous wave OPO seeded pulsed dye amplifier for high-resolution laser spectroscopy
- 2023
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9781510659032
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Konferensbidrag (refereegranskat)abstract
- The study of the atomic spectrum via resonant laser excitation provides access to underlying effects caused by the nuclear structure, which is of special interest in short-lived radioisotopes produced at Isotope Separator On-Line (ISOL) facilities. Current implementations of resonant laser ionization techniques often limit the extraction of the nuclear observables due to the low spectral resolution of the pulsed laser systems deployed. Several high-resolution spectroscopy techniques demand spectral widths in the order of hundreds of MHz and below. A proven solution to reduce this linewidth is the pulsed amplification of a narrow-band continuous wave (cw) laser. This work presents the demonstration of a pulsed dye amplifier seeded by a commercially available cw Optical Parametric Oscillator (OPO). The performance of this system was compared with competing setups using a cw dye laser seed source as well as a frequency mixing technique using a combination of an injection-locked titanium:sapphire (Ti:Sa) and a Nd:YVO4 laser. Spectral bandwidths of the systems were measured using a high finesse Fabry-Perot Interferometer, resulting in comparable optical linewidths between 140 to 156 MHz at a wavelength of 328 nm for the different laser setups. Suitability for on-line experiments was validated by performing high-resolution spectroscopy of radioactive silver isotopes in the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the Isotope Separator On-Line Device (ISOLDE), at the European Organization for Nuclear Research (CERN). The quality of the hyperfine spectra was similar for the dye and the OPO seed and the deduced hyperfine splitting was in good agreement with literature, while the frequency mixing technique exhibited less precise results attributed to the frequency instabilities and mode-hops of the single-mode Nd:YVO4 laser.
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