Calculation of isotope shifts and relativistic shifts in CI, CII, CIII and CIV

We present an accurate ab initio method of calculating isotope shifts and relativistic shifts in atomic spectra. We test the method on neutral carbon and three carbon ions. The relativistic shift of carbon lines may allow them to be included in analyses of quasar absorption spectra that seek to measure possible variations in the fine structure constant, alpha, over the lifetime of the Universe. Carbon isotope shifts can be used to measure isotope abundances in gas clouds: isotope abundances are potentially an important source of systematic error in the alpha-variation studies. These abundances are also needed to study nuclear reactions in stars and supernovae, and test models of chemical evolution of the Universe

Gravitational lensing statistics with extragalactic surveys. II. Analysis of the Jodrell Bank-VLA Astrometric Survey

We present constraints on the cosmological constant $\lambda_{0}$ from gravitational lensing statistics of the Jodrell Bank-VLA Astrometric Survey (JVAS). Although this is the largest gravitational lens survey which has been analysed, cosmological constraints are only comparable to those from optical surveys. This is due to the fact that the median source redshifts of JVAS are lower, which leads to both relatively fewer lenses in the survey and a weaker dependence on the cosmological parameters. Although more approximations have to be made than is the case for optical surveys, the consistency of the results with those from optical gravitational lens surveys and other cosmological tests indicate that this is not a major source of uncertainty in the results. However, joint constraints from a combination of radio and optical data are much tighter. Thus, a similar analysis of the much larger Cosmic Lens All-Sky Survey should provide even tighter constraints on the cosmological constant, especially when combined with data from optical lens surveys. At 95% confidence, our lower and upper limits on $\lambda_{0}-\Omega_{0}$, using the JVAS lensing statistics information alone, are respectively -2.69 and 0.68. For a flat universe, these correspond to lower and upper limits on \lambda_{0} of respectively -0.85 and 0.84. Using the combination of JVAS lensing statistics and lensing statistics from the literature as discussed in Quast & Helbig (Paper I) the corresponding $\lambda_{0}-\Omega_{0}$ values are -1.78 and 0.27. For a flat universe, these correspond to lower and upper limits on $\lambda_{0}$ of respectively -0.39 and 0.64.Comment: LaTeX, 9 pages, 18 PostScript files in 6 figures. Paper version available on request. Data available from http://gladia.astro.rug.nl:8000/ceres/data_from_papers/papers.htm

What Fraction of Gravitational Lens Galaxies Lie in Groups?

We predict how the observed variations in galaxy populations with environment affect the number and properties of gravitational lenses in different environments. Two trends dominate: lensing strongly favors early-type galaxies, which tend to lie in dense environments, but dense environments tend to have a larger ratio of dwarf to giant galaxies than the field. The two effects nearly cancel, and the distribution of environments for lens and non-lens galaxies are not substantially different (lens galaxies are slightly less likely than non-lens galaxies to lie in groups and clusters). We predict that about 20% of lens galaxies are in bound groups (defined as systems with a line-of-sight velocity dispersion sigma in the range 200 < sigma < 500 km/s), and another roughly 3% are in rich clusters (sigma > 500 km/s). Therefore at least roughly 25% of lenses are likely to have environments that significantly perturb the lensing potential. If such perturbations do not significantly increase the image separation, we predict that lenses in groups have a mean image separation that is about 0.2'' smaller than that for lenses in the field and estimate that 20-40 lenses in groups are required to test this prediction with significance. The tail of the distribution of image separations is already illuminating. Although lensing by galactic potential wells should rarely produce lenses with image separations theta >~ 6'', two such lenses are seen among 49 known lenses, suggesting that environmental perturbations of the lensing potential can be significant. Further comparison of theory and data will offer a direct probe of the dark halos of galaxies and groups and reveal the extent to which they affect lensing estimates of cosmological parameters.Comment: 32 pages, 6 embedded figures; accepted for publication in Ap

Scale Dependence of Dark Energy Antigravity

We investigate the effects of negative pressure induced by dark energy (cosmological constant or quintessence) on the dynamics at various astrophysical scales. Negative pressure induces a repulsive term (antigravity) in Newton's law which dominates on large scales. Assuming a value of the cosmological constant consistent with the recent SnIa data we determine the critical scale $r_c$ beyond which antigravity dominates the dynamics ($r_c \sim 1Mpc$) and discuss some of the dynamical effects implied. We show that dynamically induced mass estimates on the scale of the Local Group and beyond are significantly modified due to negative pressure. We also briefly discuss possible dynamical tests (eg effects on local Hubble flow) that can be applied on relatively small scales (a few $Mpc$) to determine the density and equation of state of dark energy.Comment: Contributed talk at the 2nd Hellenic Cosmology Workshop at NOA (Athens) Jan. 2001.To appear in the proceedings. Based on work done in collaboration with M. Axenides and E. Florato

Measuring Cosmological Parameters with the JVAS and CLASS Gravitational Lens Surveys

The JVAS (Jodrell Bank-VLA Astrometric Survey) and CLASS (Cosmic Lens All-Sky Survey) are well-defined surveys containing about ten thousand flat-spectrum radio sources. For many reasons, flat-spectrum radio sources are particularly well-suited as a population from which one can obtain unbiased samples of gravitational lenses. These are by far the largest gravitational (macro)lens surveys, and particular attention was paid to constructing a cleanly-defined sample for the survey itself and for the underlying luminosity function. Here we present the constraints on cosmological parameters, particularly the cosmological constant, derived from JVAS and combine them with constraints from optical gravitational lens surveys, `direct' measurements of $\Omega_{0}$, $H_{0}$ and the age of the universe, and constraints derived from CMB anisotropies, before putting this final result into the context of the latest results from other, independent cosmological tests.Comment: LaTeX, 9 pages, 6 PostScript figures, uses texas.sty. To appear in the Proceedings of the 19th Texas Symposium on Relativistic Astrophysics and Cosmology (CD-ROM). Paper version available on request. Actual poster (A0 and A4 versions) available from http://multivac.jb.man.ac.uk:8000/helbig/research/publications/info/ texas98.htm

First measurement of Mg isotope abundances at high redshifts and accurate estimate of Delta alpha/alpha

(Abridged) We use a high-resolution spectrum of the quasar HE0001-2340 observed with the UVES/VLT to measure Mg isotope abundances in the intervening absorption-line systems at high redshifts. Line profiles are prepared accounting for possible shifts between the individual exposures. Due to unique composition of the selected systems - the presence of several transitions of the same ion - we can test the local accuracy of the wavelength scale calibration which is the main source of errors in the sub-pixel line position measurements. In the system at zabs = 0.45 which is probably a fragment of the outflow caused by SN Ia explosion of high-metallicity white dwarf(s) we measured velocity shifts of MgII and MgI lines relative to other lines (FeI, FeII, CaI, CaII): Delta V(MgII) = -0.44 +/- 0.05 km/s and Delta V(MgI) = -0.17 +/- 0.17$ km/s. This translates into the isotopic ratio 24Mg:25Mg:26Mg = (19 +/- 11):(22 +/- 13):(59 +/- 6) with a strong relative overabundance of heavy Mg isotopes, (25Mg+26Mg)/24Mg = 4, as compared to the solar ratio 24Mg:25Mg:26Mg = 79:10:11, and (25Mg+26Mg)/24Mg = 0.3. At zabs = 1.58, we put a strong constraint on a putative variation of alpha: Delta alpha/alpha = (-1.5 +/- 2.6)x10^{-6} which is one of the most stringent limits obtained from optical spectra of QSOs. We reveal that the wavelength calibration in the range above 7500 A is subject to systematic wavelength-dependent drifts.Comment: 20 pages, 13 figures, 7 tables. Accepted for publication in Astronomy and Astrophysic

Improved Cosmological Constraints from Gravitational Lens Statistics

We combine the Cosmic Lens All-Sky Survey (CLASS) with new Sloan Digital Sky Survey (SDSS) data on the local velocity dispersion distribution function of E/S0 galaxies, $\phi(\sigma)$, to derive lens statistics constraints on $\Omega_\Lambda$ and $\Omega_m$. Previous studies of this kind relied on a combination of the E/S0 galaxy luminosity function and the Faber-Jackson relation to characterize the lens galaxy population. However, ignoring dispersion in the Faber-Jackson relation leads to a biased estimate of $\phi(\sigma)$ and therefore biased and overconfident constraints on the cosmological parameters. The measured velocity dispersion function from a large sample of E/S0 galaxies provides a more reliable method for probing cosmology with strong lens statistics. Our new constraints are in good agreement with recent results from the redshift-magnitude relation of Type Ia supernovae. Adopting the traditional assumption that the E/S0 velocity function is constant in comoving units, we find a maximum likelihood estimate of $\Omega_\Lambda = 0.74$--0.78 for a spatially flat unvierse (where the range reflects uncertainty in the number of E/S0 lenses in the CLASS sample), and a 95% confidence upper bound of $\Omega_\Lambda<0.86$. If $\phi(\sigma)$ instead evolves in accord with extended Press-Schechter theory, then the maximum likelihood estimate for $\Omega_\Lambda$ becomes 0.72--0.78, with the 95% confidence upper bound $\Omega_\Lambda<0.89$. Even without assuming flatness, lensing provides independent confirmation of the evidence from Type Ia supernovae for a nonzero dark energy component in the universe.Comment: 35 pages, 15 figures, to be published in Ap

Chemical And Physical Characterization Of Mume Fruit Collected From Different Locations And At Different Maturity Stages In São Paulo State

Prunus mume is widely studied due to its health benefits regarding increase of blood fluidity and consequent improvement of the cardiovascular system and the prevention or even the fight against different types of cancer. However, in Brazil this culture is found only among oriental descendants. The present study aimed to characterize mume fruit collected from three different locations in the State of São Paulo regarding general aspects such as pH, total titratable acidity (TTA), total soluble solids (TTS), pectin content and yield of pulp and chemical characteristics: total phenolic compounds (TPC) and antioxidant capacity. Mume fruit were collected unripe and analyzed until maturation about 88 days after flowering. Fruit collected in Botucatu came from a commercial mume fruit producer and had average weight of 16.9 g, while in fruit from other locations weight varied from 5.7-6.9 g. TSS ranged from 9.5 to 10.0 Brix, total solids was 10.2-12.2% and pH showed values between 2.5 and 2.7 for all locations. TTA expressed in citric acid decreased from 4.0-5.7 g (100g-1) at unripe stage to 2.0-3.8 g (100g-1) in mature-stage fruit. Pectin content decreased from 11.2 to 10.8% during fruit maturation, TPC content was 147-226 mg catechin (g-1) on a dry matter basis and the antioxidant capacity was 96-169 μMol Trolox (g-1) on a dry matter basis or 21-34 μMol Trolox (g-1) on a wet matter basis.333441445Adachi, M., The Prunus mume Sieb. et Zucc (Ume) is a rich natural source of novel anti-cancer substance (2007) International Journal of Food Properties, 10 (2), pp. 375-384. , http://dx.doi.org/10.1080/10942910600547624Baker, R.A., Reassessment of some fruit and vegetable pectin levels (1997) Journal of Food Science, 62 (2), pp. 225-229. , http://dx.doi.org/10.1111/j.1365-2621.1997.tb03973.xBenzie, I.F.F., Strain, J.J., The ferric reducing ability of plasma (FRAP) as a measure of "antioxidant power": The FRAP assay (1996) Analytical Biochemistry, 239, pp. 70-76(2008) Normas Analíticas Do Instituto Adolfo Lutz: Métodos Químicos E Físicos Para Análise De Alimentos, p. 1020. , 4. ed. São Paulo: Secretaria de Estado da Saúde, INSTITUTO ADOLFO LUTZ - IALJo, S.-C., Antioxidant activity of Prunus mume extract in cooked chicken breast meat (2006) International Journal of Food Science and Technology, 41 (1), pp. 15-19. , http://dx.doi.org/10.1111/j.1365-2621.2006.01234.xJun, J.H., Chung, K.H., Development of SCAR markers to differentiate between mume (Prunus mume Sieb. et Zucc.) and apricot (P. armeniaca L.) (2008) Journal of Horticultural Science & Biotechnology, 83 (3), pp. 318-322Liu, L., The possible mechanisms of Fructus Mume pill in the treatment of colitis induced by 2,4,6-trinitrobenzene sulfonic acid in rats (2009) Journal of Ethnopharmacology, 126, pp. 557-564. , http://dx.doi.org/10.1016/j.jep.2009.08.013, PMid:19703546Lorenzi, H., (2006) Frutas Brasileiras E Exóticas Cultivadas: (de Consumo In Natura), , São Paulo: Instituto PlantarumLuo, Z., Hot water treatment of postharvest mei fruit to delay ripening (2006) HortScience, 41 (3), pp. 737-740Mayer, N.A., Pereira, F.M., Môro, F.V., Caracterização morfológica de três genótipos de umezeiro selecionados como porta-enxertos para pessegueiro (2008) Revista Brasileira De Fruticultura, 30 (3), pp. 716-722. , http://dx.doi.org/10.1590/S0100-29452008000300026McGhie, T.K., Hunt, M., Barnett, L.E., Cultivar and growing region determine the antioxidant polyphenolic concentration and composition of apples grown in New Zealand (2005) Journal of Agricultural and Food Chemistry, 53 (8), pp. 3065-3070. , http://dx.doi.org/10.1021/jf047832r, PMid:15826060Miyazawa, M., Comparision of the volatile componentes of unripe and ripe Japanese apricot (Prunus mume Sieb. et Zucc.) (2009) Natural Product Research, 23 (17), pp. 1567-1571. , http://dx.doi.org/10.1080/14786410500462926, PMid:19851921Penniston, K.L., Quantitative assessment of citric acid in lemon juice, lime juice, and commercially-available fruit juice products (2008) Journal of Endourology, 22 (3), pp. 567-570. , http://dx.doi.org/10.1089/end.2007.0304, PMid:18290732 PMCid:PMC2637791Quast, E., Prunus mume - fruit characteristics and phenolic content capacity (2011) Fruit Processing, pp. 238-242. , Nov/DecRupasinghe, H.P.V., Jayasankar, S., Lay, W., Variation in total phenolics and antioxidant capacity among European plum genotypes (2006) Scientia Horticulturae, 108 (3), pp. 243-246. , http://dx.doi.org/10.1016/j.scienta.2006.01.020Shi, J., Moy, J.H., Functional foods from fruit and fruit products (2005) Asian Functional Foods, pp. 303-339. , http://dx.doi.org/10.1201/9781420028119, SHI, J.HO, C.-T.SHAHIDI, F., Boca Raton: CRC PressShi, J., Antioxidant capacity of extract from edible flowers of Prunus mume in China and its active components (2009) LWT - Food Science and Technology, 42 (2), pp. 477-482Singleton, V.L., Rossi Jr., J.A., Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents (1965) American Journal of Enology and Viticulture, 16 (3), pp. 144-158Souza, V.C., Lorenzi, H., (2005) Botanica Sistemática: Guia Ilustrado Para Identificação Das Famílias De Angiospermas Da Flora Brasileira, , baseado em APG II. São Paulo: Instituto PlantarumThaipong, K., Comparison of ABTS, DPPH, FRAP and ORAC assays for estimating antioxidant activity from guava fruit extracts (2006) Journal of Food Composition and Analysis, 19, pp. 669-675Topp, B.L., Noller, J., Russell, D.M., (2007) Development of Prunus Mume, a New Tree Crop For Australia, p. 113. , Australia: Rural Industries Research and Development CorporationTsubaki, S., Ozaki, Y., Azuma, J., Microwave-assisted autohydrolysis of Prunus mume stone for extraction of polysaccharides and phenolic compounds (2010) Journal of Food Science, 75 (2), pp. 152-157. , http://dx.doi.org/10.1111/j.1750-3841.2009.01466.x, PMid:2049221

SACY - a Search for Associations Containing Young stars

The scientific goal of the SACY (Search for Associations Containing Young-stars) was to identify possible associations of stars younger than the Pleiades Association among optical counterparts of the ROSAT X-ray bright sources. High-resolution spectra for possible optical counterparts later than G0 belonging to HIPPARCOS and/or TYCHO-2 catalogs were obtained in order to assess both the youth and the spatial motion of each target. More than 1000 ROSAT sources were observed, covering a large area in the Southern Hemisphere. The newly identified young stars present a patchy distribution in UVW and XYZ, revealing the existence of huge nearby young associations. Here we present the associations identified in this survey.Comment: 8 pages, 2 figures, to appear in the Proceedings of Open Issues in Local Formation and Early Stellar Evolution, Ouro Preto, Brazi

Disk Imaging Survey of Chemistry with SMA: II. Southern Sky Protoplanetary Disk Data and Full Sample Statistics

This is the second in a series of papers based on data from DISCS, a Submillimeter Array observing program aimed at spatially and spectrally resolving the chemical composition of 12 protoplanetary disks. We present data on six Southern sky sources - IM Lup, SAO 206462 (HD 135344b), HD 142527, AS 209, AS 205 and V4046 Sgr - which complement the six sources in the Taurus star forming region reported previously. CO 2-1 and HCO+ 3-2 emission are detected and resolved in all disks and show velocity patterns consistent with Keplerian rotation. Where detected, the emission from DCO+ 3-2, N2H+ 3-2, H2CO 3-2 and 4-3,HCN 3-2 and CN 2-1 are also generally spatially resolved. The detection rates are highest toward the M and K stars, while the F star SAO 206462 has only weak CN and HCN emission, and H2CO alone is detected toward HD 142527. These findings together with the statistics from the previous Taurus disks, support the hypothesis that high detection rates of many small molecules depend on the presence of a cold and protected disk midplane, which is less common around F and A stars compared to M and K stars. Disk-averaged variations in the proposed radiation tracer CN/HCN are found to be small, despite two orders of magnitude range of spectral types and accretion rates. In contrast, the resolved images suggest that the CN/HCN emission ratio varies with disk radius in at least two of the systems. There are no clear observational differences in the disk chemistry between the classical/full T Tauri disks and transitional disks. Furthermore, the observed line emission does not depend on measured accretion luminosities or the number of infrared lines detected, which suggests that the chemistry outside of 100 AU is not coupled to the physical processes that drive the chemistry in the innermost few AU.Comment: accepted for publication in ApJ, 41 pages including 7 figure