Nonthermal Mg I Emission At 12 Micron From Procyon

We report on stellar Mg i emission at 12 mu m from alpha CMi (Procyon), a star slightly hotter than the Sun. Solar Mg i emission is well known, and its formation was successfully explained in detail by Carlsson et al. Here, for the first time, we successfully model and compare synthetic spectra of the emission lines at 12 mu m with observations of a star other than the Sun. The use of these lines as stellar diagnostics has been anticipated for 10 years or more (see, e.g., Carlsson et al.). We find that the model reproduces the observed emission in Procyon quite well. We expect that high-resolution spectrographs on 8-10 m telescopes will finally be able to exploit these new diagnostics.Swedish Research Councils VRSTINTNSF AST 03-07497Texas Advanced Research ProgramAstronom

The Determination of Stellar Parameters of Giants in the Galactic Disks and Bulge

Here, we present our on-going work on the determination of stellar parameters of giants in the Galactic Disks and Bulge observed with UVES on the VLT. We present some preliminarily results.Comment: 2 pages, IAU241 conference proceeding

Sulphur abundances in metal-poor stars

We investigate the debated "sulphur discrepancy" found among metal-poor stars of the Galactic halo with [Fe/H] < -2. This discrepancy stems in part from the use of two different sets of sulphur lines, the very weak triplet at 8694-95 A and the stronger triplet lines at 9212 - 9237 A. For three representative cases of metal-poor dwarf, turnoff and subgiant stars, we argue that the abundances from the 8694-95 lines have been overestimated which has led to a continually rising trend of [S/Fe] as metallicity decreases. Given that the near-IR region is subject to CCD fringing, these weak lines become excessively difficult to measure accurately in the metallicity regime of [Fe/H] < -2. Based on homogeneously determined spectroscopic stellar parameters, we also present updated [S/Fe] ratios from the 9212-9237 lines which suggest a plateau-like behaviour similar to that seen for other alpha elements.Comment: accepted by A&A, 4 pages, 3 tables, 1 figure; v2: Table2 updated with metallicities from other work

Promoting male refugees’ mental health after they have been granted Leave to Remain (refugee status)

There is existing evidence that suggests that refugees’ mental health is often impaired by pre-migratory stress, by their experience of being asylum seekers and also by their resettlement adversities; however, little is known about the specific mental health issues of male refugees. The current research is set in this context and it aims to explore multiple levels of stress that male refugees experience after they have been granted Leave to Remain (refugee status) in the U.K. A total of nine male refugees took part in the study; they were interviewed individually and the interview transcripts were analysed by the use of Thematic Analysis. The overall findings indicated that being granted Leave to Remain worsened participants’ mental health, as they had to face new challenges such as seeking employment and accommodation, as well as their general struggle to settle in the U.K. Participants indicated that the type of support available to them was quite poor. These findings are relevant in order to support specific intervention strategies to promote male refugees’ mental health

Modelling CO emission from Mira's wind

We have modelled the circumstellar envelope of {\it o} Ceti (Mira) using new observational constraints. These are obtained from photospheric light scattered in near-IR vibrational-rotational lines of circumstellar CO molecules at 4.6 micron: absolute fluxes, the radial dependence of the scattered intensity, and two line ratios. Further observational constraints are provided by ISO observations of far-IR emission lines from highly excited rotational states of the ground vibrational state of CO, and radio observations of lines from rotational levels of low excitation of CO. A code based on the Monte-Carlo technique is used to model the circumstellar line emission. We find that it is possible to model the radio and ISO fluxes, as well as the highly asymmetric radio-line profiles, reasonably well with a spherically symmetric and smooth stellar wind model. However, it is not possible to reproduce the observed NIR line fluxes consistently with a `standard model' of the stellar wind. This is probably due to incorrectly specified conditions of the inner regions of the wind model, since the stellar flux needs to be larger than what is obtained from the standard model at the point of scattering, i.e., the intermediate regions at approximately 100-400 stellar radii (2"-7") away from the star. Thus, the optical depth in the vibrational-rotational lines from the star to the point of scattering has to be decreased. This can be accomplished in several ways. For instance, the gas close to the star (within approximately 2") could be in such a form that light is able to pass through, either due to the medium being clumpy or by the matter being in radial structures (which, further out, developes into more smooth or shell-like structures).Comment: 18 pages, 3 figures, accepted for publication in Ap

Farmers record keeping and planning practices : a postal survey

With the advent of the personal computer (micro computer) there is a need to develop software suitable for use by farmers. To gauge this requirement a postal survey of 1,500 farmers was conducted in early 1982 eliciting information on recording and planning practices as well as farmers' attitude to micro computers. The data collected suggest significant numbers of farmers do, in fact, keep detailed records particularly in the financial area, and make written plans in the form of documents such as a forecast budget. The responses also indicated a positive view of micro computers as an aid to management is held by many farmers. However, there is most unlikely to be a perfect correlation between recorded intentions and what eventually takes place

Mg I emission lines at 12 and 18 micrometer in K giants

The solar Mg I emission lines at 12 micrometer have already been observed and analyzed well. Previous modeling attempts for other stars have, however, been made only for Procyon and two cool evolved stars, with unsatisfactory results for the latter. We present high-resolution observational spectra for the K giants Pollux, Arcturus, and Aldebaran, which show strong Mg I emission lines at 12 micrometer as compared to the Sun. We also present the first observed stellar emission lines from Mg I at 18 micrometer and from Al I, Si I, and presumably Ca I at 12 micrometer. To produce synthetic line spectra, we employ standard non-LTE modeling for trace elements in cool stellar photospheres. We compute model atmospheres with the MARCS code, apply a comprehensive magnesium model atom, and use the radiative transfer code MULTI to solve for the magnesium occupation numbers in statistical equilibrium. We successfully reproduce the observed Mg I emission lines simultaneously in the giants and in the Sun, but show how the computed line profiles depend critically on atomic input data and how the inclusion of energy levels with n > 9 and collisions with neutral hydrogen are necessary to obtain reasonable fits.Comment: 9 pages, 6 figures, accepted for publication in Astronomy & Astrophysic