Molybdenum, Ruthenium, and the Heavy r-process Elements in Moderately Metal-Poor Main-Sequence Turnoff Stars

The ratios of elemental abundances observed in metal-poor stars of the Galactic halo provide a unique present-day record of the nucleosynthesis products of its earliest stars. While the heaviest elements were synthesized by the r- and s-processes, dominant production mechanisms of light trans-ironic elements were obscure until recently. This work investigates further our 2011 conclusion that the low-entropy regime of a high-entropy wind (HEW) produced molybdenum and ruthenium in two moderately metal-poor turnoff stars that showed extreme overabundances of those elements with respect to iron. Only a few, rare nucleosynthesis events may have been involved. Here we determine abundances for Mo, Ru, and other trans-Fe elements for 28 similar stars by matching spectral calculations to well-exposed near-UV Keck HIRES spectra obtained for beryllium abundances. In each of the 26 turnoff stars with Mo or Ru line detections and no evidence for s-process production (therefore old), we find Mo and Ru to be three to six times overabundant. In contrast, the maximum overabundance is reduced to factors of three and two for the neighboring elements zirconium and palladium. Since the overproduction peaks sharply at Mo and Ru, a low-entropy HEW is confirmed as its origin. The overabundance level of the heavy r-process elements varies significantly, from none to a factor of four, but is uncorrelated with Mo and Ru overabundances. Despite their moderate metallicity, stars in this group trace the products of different nucleosynthetic events: possibly very few events, possibly events whose output depended on environment, metallicity, or time.Comment: Accepted April 2, 2013, for publication in the Astrophysical Journal Letters (7 pages, 3 figures

Comparing Ultraviolet Spectra against Calculations: Year 2 Results

The five-year goal of this effort is to calculate high fidelity mid-W spectra for individual stars and stellar systems for a wide range of ages, abundances, and abundance ratios. In this second year, the comparison of our calculations against observed high-resolution mid- W spectra was extended to stars as metal-rich as the Sun, and to hotter and cooler stars, further improving the list of atomic line parameters used in the calculations. We also published the application of our calculations based on the earlier list of line parameters to the observed mid-UV and optical spectra of a mildly metal-poor globular cluster in the nearby Andromeda galaxy, Messier 3 1

A Survey for EHB Stars in the Galactic Bulge

We present a progress report on an extensive survey to find and characterize all types of blue horizontal-branch stars in the nuclear bulge of the Galaxy. We have obtained wide, shallow imaging in UBV of ~12 square degrees in the bulge, with follow-up spectroscopy for radial velocities and metal abundance determinations. We have discovered a number of metal-rich blue HB stars, whose presence in the bulge is expected by the interpretation of the extragalactic ultraviolet excess. Very deep images have been obtained in UBV and SDSS u along the bulge minor axis, which reveal a significant number of EHB candidates fainter than B = 19, i.e., with the same absolute magnitudes as EHB stars in several globular clusters.Comment: To appear in "Extreme Horizontal Branch Stars and Related Objects", Astrophysics and Space Science, Kluwer Academic Publishers, proceedings of the meeting held in Keele, UK, June 16-20, 200

Rape and Dimensions of Gender Socioeconomic Inequality in U.S. Metropolitan Areas

There is a growing consensus that a major cause of the rape problem is the subordinate position of women in the social, political, and economic order. Despite this consensus, there have been few structural analyses of rape and inequality. Further, extant investigations suffer from a number of serious shortcomings such that, at present, there is not a sound basis for accepting, or rejecting, rape and inequality arguments. Correcting for many of the limitations of previous studies, this investigation extends our understanding of the role of gender socioeconomic inequality and other structural factors in the etiology of rape. The authors examine the relationship between rape rates and various measures of general, racial, and gender socioeconomic inequality for U.S. metropolitan areas. Their findings show that gender income inequality is a significant contributor to rape, but gender inequities in educational attainment and occupational status do not contribute significantly to this offense. The analysis also points to a number of other structural factors, including general income inequality, that are powerful predictors of rape

Rape and Dimensions of Gender Socioeconomic Inequality in U.S. Metropolitan Areas

There is a growing consensus that a major cause of the rape problem is the subordinate position of women in the social, political, and economic order. Despite this consensus, there have been few structural analyses of rape and inequality. Further, extant investigations suffer from a number of serious shortcomings such that, at present, there is not a sound basis for accepting, or rejecting, rape and inequality arguments. Correcting for many of the limitations of previous studies, this investigation extends our understanding of the role of gender socioeconomic inequality and other structural factors in the etiology of rape. The authors examine the relationship between rape rates and various measures of general, racial, and gender socioeconomic inequality for U.S. metropolitan areas. Their findings show that gender income inequality is a significant contributor to rape, but gender inequities in educational attainment and occupational status do not contribute significantly to this offense. The analysis also points to a number of other structural factors, including general income inequality, that are powerful predictors of rape

An Extremely Lithium-Rich Bright Red Giant in the Globular Cluster M3

We have serendipitously discovered an extremely lithium-rich star on the red giant branch of the globular cluster M3 (NGC 5272). An echelle spectrum obtained with the Keck I HIRES reveals a Li I 6707 Angstrom resonance doublet of 520 milli-Angstrom equivalent width, and our analysis places the star among the most Li-rich giants known: log[epsilon(Li)] ~= +3.0. We determine the elemental abundances of this star, IV-101, and three other cluster members of similar luminosity and color, and conclude that IV-101 has abundance ratios typical of giants in M3 and M13 that have undergone significant mixing. We discuss mechanisms by which a low-mass star may be so enriched in Li, focusing on the mixing of material processed by the hydrogen-burning shell just below the convective envelope. While such enrichment could conceivably only happen rarely, it may in fact regularly occur during giant-branch evolution but be rarely detected because of rapid subsequent Li depletion.Comment: 7-page LaTeX file, including 2 encapsulated ps figures + 1 table; accepted for publication in the Astrophysical Journal Letter

The pain of low status: the relationship between subjective socio-economic status and analgesic prescriptions in a Scottish community sample

There is a strong positive relationship between objective measures of socioeconomic status (OSS) and general health. However, there is an increasing interest in the relationship between health and subjective socioeconomic status (SSS), which describes one’s perceived rank in relation to the rest of society, based on factors such as income, occupation, and education. While the relationship between SSS and general health is well2established, the relationship between SSS and pain has received little attention. Gathering both self2report questionnaire data and General Practitioner medical data from a large representative community sample in Scotland between 2012 and 2013 ( N = 1824), we investigated the relationship between SSS and prescriptions for analgesic drugs. We found that higher levels of SSS significantly predicted lower odds of participants having been prescribed at least one analgesic drug in the previous six months. We obtained this result even after controlling for OSS2related variables (education, occupational status, and geographical location) and demographic variables (age and gender). This suggests that, just like the relationship between SSS and general health, SSS has important effects on pain that go beyond the influence of OSS

Hot Horizontal Branch Stars in the Galactic Bulge. I

We present the first results of a survey of blue horizontal branch (BHB) stars in the Galactic bulge. 164 candidates with 15 < V < 17.5 in a field 7.5deg from the Galactic Center were observed in the blue at 2.4A FWHM resolution with the AAT 2dF spectrograph. Radial velocities were measured for all stars. For stars with strong Balmer lines, their profiles were matched to theoretical spectrum calculations to determine stellar temperature Teff and gravity log g; matches to metal lines yielded abundances. CTIO UBV photometry then gave the reddening and distance to each hot star. Reddening was found to be highly variable, with E(B-V) from 0.0 to 0.55 around a mean of 0.28. Forty-seven BHB candidates were identified with Teff >= 7250K, of which seven have the gravities of young stars, three are ambiguous, and 37 are HB stars. They span a wide metallicity range, from solar to 1/300 solar. The warmer BHB's are more metal-poor and loosely concentrated towards the Galactic center, while the cooler ones are of somewhat higher metallicity and closer to the center. Their red B-V colors overlap main-sequence stars, but the U-B vs. B-V diagram separates them until E(B-V) > 0.5. We detect two cool solar-metallicity HB stars in the bulge of our own Galaxy, the first such stars known. Still elusive are their hot counterparts, the metal-rich sdB/O stars causing excess UV light in metal-rich galaxies; they have V ~ 20.5 in the Bulge.Comment: 29 pages, 4 figures (the third with 4 panels, the fourth with 2 panels). To appear in the Astrophysical Journal v571n1, Jan. 20, 2000. Abstract is shortened here, and figures compresse