Context. Carbon-enhanced metal poor stars (CEMP) form a significant proportion of the metal-poor stars, their origin is not well understood, and this carbon-enhancement appears in stars that exhibit different abundance patterns. Aims. Three very metal-poor C-rich turnoff stars were selected from the SDSS survey, observed with the ESO VLT (UVES) to precisely determine the element abundances. In ...

Measurements of ultra heavy nuclei at GeV/n energies in the galactic cosmic radiation address the question of the sources (nucleosynthetic sand r-processes). As such, the determination of CR source abundances is a promising way to discriminate between existing nucleosynthesis models. For primary species (nuclei present and accelerated at sources), it is generally assumed that the relative propa...

Abundances for 5 molecules (CO, CS, NH3, H2CO, and C3H2) and 1 molecular ion (N2H ) and upper limits for the abundances of 1 molecule (CO) and 1 molecular ion (HCO) are derived for gas within the Bok globule Barnard 68 (B68). The abundances were determined using our own BIMA millimeter interferometer data and single-dish data gathered from the literature, in conjunction with a Monte Carlo radia...

We examine the practice of deriving interstellar medium (ISM) abundances from low-resolution spectroscopy of GRB afterglows. We argue that the multi-ion single-component curve-of-growth analysis technique systematically underestimates the column densities of the metal-line profiles commonly observed for GRB. This systematic underestimate is accentuated by the fact that many GRB line-profiles (e...

We present a study of elemental abundances in a sample of thirteen Blue Compact Dwarf (BCD) galaxies, using the ∼10–37μm high resolution spectra obtained with Spitzer/IRS. We derive the abundances of neon and sulfur for our sample using the infrared fine-structure lines probing regions which may be obscured by dust in the optical and compare our results with similar infrared studies of starburs...

We present a 1D LTE chemical abundance analysis of the very bright (V = 9.1) Carbon-Enhanced Metal-Poor (CEMP) star BD+44493, based on high-resolution, high signal-to-noise spectra obtained with Subaru/HDS. The star is shown to be a subgiant with an extremely low iron abundance ([Fe/H] = −3.7), while it is rich in C ([C/Fe] = +1.3) and O ([O/Fe] = +1.6). Although astronomers have been searching...

Recent analyses of nebular spectra have resulted in discrepant abundances from CNO forbidden and recombination lines. We consider independent methods of determining ion abundances for emission nebulae, comparing ion emission measures with column densities derived from resonance absorption lines viewed against the central star continuum. Separate analyses of the nebular emission lines and the st...

We obtained new optical spectra of 13 H II regions in WLM with EFOSC2; oxygen abundances are derived for nine H II regions. The temperature-sensitive [O III]λ4363 emission line was measured in two bright H II regions HM 7 and HM 9. The direct oxygen abundances for HM 7 and HM 9 are 12+log(O/H) = 7.72±0.04 and 7.91±0.04, respectively. We adopt a mean oxygen abundance of 12+log(O/H) = 7.83±0.06. ...

We present chemical abundances for 110 stars identified in objective-prism surveys as candidates to be very metal-poor. The abundances are derived from high S/N, intermediate-resolution spectra obtained with the Keck Observatory Echelle Spectrometer and Imager. An additional 25 stars with well-determined abundances ranging from [Fe/H]= −1.5 and −3.2 were observed and the results used to help ca...

Anthropogenic noise is a widespread and growing form of sensory pollution associated with the expansion of human infrastructure. One specific source of constant and intense noise is that produced by compressors used for the extraction and transportation of natural gas. Terrestrial arthropods play a central role in many ecosystems, and given that numerous species rely upon airborne sounds and su...