Is the Sun Embedded in a Typical Interstellar Cloud?

The physical properties and kinematics of the partially ionized interstellar material near the Sun are typical of warm diffuse clouds in the solar vicinity. The interstellar magnetic field at the heliosphere and the kinematics of nearby clouds are naturally explained in terms of the S1 superbubble shell. The interstellar radiation field at the Sun appears to be harder than the field ionizing ambient diffuse gas, which may be a consequence of the low opacity of the tiny cloud surrounding the heliosphere. The spatial context of the Local Bubble is consistent with our location in the Orion spur.Comment: "From the Outer Heliosphere to the Local Bubble", held at International Space Sciences Institute, October 200

An absorption-selected survey of neutral gas in the Milky Way halo

We aim at analysing systematically the distribution and physical properties of neutral and mildly ionised gas in the Milky Way halo, based on a large absorption-selected data set. Multi-wavelength studies were performed combining optical absorption line data of CaII and NaI with follow-up HI 21-cm emission line observations along 408 sight lines towards low- and high-redshift QSOs. We made use of archival optical spectra obtained with UVES/VLT. HI data were extracted from the Effelsberg-Bonn HI survey and the Galactic All-Sky survey. For selected sight lines we obtained deeper follow-up observations using the Effelsberg 100-m telescope. CaII (NaI) halo absorbers at intermediate and high radial velocities are present in 40-55% (20-35%) of the sightlines, depending on the column density threshold chosen. Many halo absorbers show multi-component absorption lines, indicating the presence of sub-structure. In 65% of the cases, absorption is associated with HI 21-cm emission. The CaII (NaI) column density distribution function follows a power-law with a slope of -2.2 (-1.4). Our absorption-selected survey confirms our previous results that the Milky Way halo is filled with a large number of neutral gas structures whose high column density tail represents the population of common HI high- and intermediate-velocity clouds seen in 21-cm observations. We find that CaII/NaI column density ratios in the halo absorbers are typically smaller than those in the Milky Way disc, in the gas in the Magellanic Clouds, and in damped Lyman-alpha systems. The small ratios (prominent in particular in high-velocity components) indicate a lower level of Ca depletion onto dust grains in Milky Way halo absorbers compared to gas in discs and inner regions of galaxies.Comment: 17 pages, 20 figures, accepted by A&

A primordial star in the heart of the Lion

Context: The discovery and chemical analysis of extremely metal-poor stars permit a better understanding of the star formation of the first generation of stars and of the Universe emerging from the Big Bang. aims: We report the study of a primordial star situated in the centre of the constellation Leo (SDSS J102915+172027). method: The star, selected from the low resolution-spectrum of the Sloan Digital Sky Survey, was observed at intermediate (with X-Shooter at VLT) and at high spectral resolution (with UVES at VLT). The stellar parameters were derived from the photometry. The standard spectroscopic analysis based on 1D ATLAS models was completed by applying 3D and non-LTE corrections. results: An iron abundance of [Fe/H]=--4.89 makes SDSS J102915+172927 one of the lowest [Fe/H] stars known. However, the absence of measurable C and N enhancements indicates that it has the lowest metallicity, Z<= 7.40x10^{-7} (metal-mass fraction), ever detected. No oxygen measurement was possible. conclusions: The discovery of SDSS J102915+172927 highlights that low-mass star formation occurred at metallicities lower than previously assumed. Even lower metallicity stars may yet be discovered, with a chemical composition closer to the composition of the primordial gas and of the first supernovae.Comment: To be published in A&

GMRT Observations of Interstellar Clouds in the 21cm line of Atomic Hydrogen

Nearby interstellar clouds with high (|v| >/= 10 km/s) random velocities although easily detected in NaI and CaII lines have hitherto not been detected (in emission or absorption) in the HI 21cm line. We describe here deep Giant Metrewave Radio Telescope (GMRT) HI absorption observations toward radio sources with small angular separation from bright O and B stars whose spectra reveal the presence of intervening high random velocity CaII absorbing clouds. In 5 out of the 14 directions searched we detect HI 21cm absorption features from these clouds. The mean optical depth of these detections is ~ 0.09 and FWHM is ~ 10 km/s, consistent with absorption arising from CNM clouds.Comment: 16 pages, 6 figures (included), Accepted for publication in Journal of Astrophysics & Astronomy, uses jaa.st

Preparing veterinary students for extramural clinical placement training: issues identified and a possible solution

Catriona Bell – ORCID: 0000-0001-8501-1697 https://orcid.org/0000-0001-8501-1697Item not available in this repository.Item previously deposited in the University of Edinburgh repository at: https://www.research.ed.ac.uk/en/publications/fa503683-7a33-4bb5-bcd9-8850b1949d9dExtramural clinical placement training is an important part of many veterinary degree programs and provides students with valuable learning experiences in private practice, often focusing on the management of typical first-opinion cases. In the United Kingdom, the Royal College of Veterinary Surgeons (RCVS) has a mandatory requirement that students take 26 weeks of clinical placement or extramural studies (EMS) before graduation. However, if students are to maximize their learning opportunities during these placements, it is important that they be adequately prepared. In response to recent topical issues surrounding EMS in the United Kingdom, the current project undertook an iterative consultation process with key stakeholders, including students and placement providers, to identify key issues associated with students attending placements. These findings then informed the development and content of a computer-aided learning (CAL) package titled “The EMS Driving Licence” that aimed to improve the preparation of students for placements. The CAL package included sections covering the main identified areas of concern: Preparation (including what to take), Working With People (staff and clients), Professionalism (including confidentiality), Frequently Asked Questions (from students), and Top Tips (from practitioners). The CAL package was evaluated by students, and feedback was gathered by means of a questionnaire. Students recognized that the content addressed many of their concerns, and all reported that they would recommend the package to others. The CAL package has been made available to all UK veterinary schools and has received backing from the RCVS as part of their current recommendations on EMS to the UK veterinary profession.The development of the EMS Driving Licence was supported by a mini-project grant from the Higher Education Academy Subject Centre for Medicine, Dentistry and Veterinary Medicine, Newcastle Upon Tyne, UK. The evaluation was supported by an Innovation Fund award from the Centre for Excellence in Professional Placement Learning, University of Plymouth, Plymouth, UK.https://doi.org/10.3138/jvme.37.2.19037pubpub

High-resolution observations of interstellar Na I and Ca II towards the southern opening of the 'Local Interstellar Chimney': probing the disc—halo connection

We present high-resolution (R = 400 000) observations of interstellar Ca II and Na I absorption lines towards seven stars in the direction of the southern opening of the recently identified Local Interstellar Chimney. These lines of sight probe the lower Galactic halo (0.3 ≲∣z∣≲ 2.5 kpc), without the complication of sampling dense foreground interstellar material. In addition to components with velocities expected from Galactic rotation, these stars also exhibit components with negative local standard of rest velocities, which are contrary to the sense of Galactic rotation for the sightlines observed. After a discussion of possible origins for these peculiar velocities, we conclude that at least some of them result from gas falling towards the Galactic plane from distances of ∣z∣≳ 300 pc. The narrow linewidths are generally inconsistent with temperatures as high as the ∼6000 K generally assumed for the so-called Lockman layer. Rather, the picture that emerges is one of a scattered, generally infalling, population of high-∣z∣ diffuse clouds, seemingly not very different from those encountered in the local interstellar medium. Overall, we argue that our results are most consistent with a ‘Galactic fountain’ model

Early-type stars observed in the ESO UVES Paranal Observatory Project - IV. Studies of CN, CH+ and CH in the interstellar medium

peer reviewedHigh spectral resolution (˜80 000) and signal-to-noise observations from the Ultraviolet and Visual Echelle Spectrograph Paranal Observatory Project (UVES-POP) are used to study the interstellar molecular lines CN (3874 Å), CH[SUP]+[/SUP] (3957, 4232 Å) and CH (3886, 4300 Å) towards 74 O- and B-type stellar sightlines. Additionally, archive data are presented for 140 ELODIE early-type stellar sightlines at R = 42 000, plus 25 FEROS at R = 48 000 and 3 UVES at R > 50 000, mainly in the CH[SUP]+[/SUP] (4232 Å) and CH (3886, 4300 Å) transitions. Detection rates are ˜45 per cent for CN and ˜67 per cent for the other lines in the POP sample, and ˜10-15 per cent for CH[SUP]+[/SUP] and CH lines in the additional sample. CH and CH[SUP]+[/SUP] are well correlated between log[N(CH) cm[SUP]-2[/SUP]]˜12-14, implying that these clouds are CH[SUP]+[/SUP]-like CH and not CN-like CH. CH is also very well correlated with Na I D in the range log[N(Na I cm[SUP]-2[/SUP]]) ˜12.2-14.2. A few sightlines show tentative velocity shifts of ˜2 km s[SUP]-1[/SUP] between CH and CH[SUP]+[/SUP], which appear to be caused by differences in component strength in blends, and hence do not provide firm evidence for shocks. Finally, we describe a search for [SUP]13[/SUP]CH[SUP]+[/SUP] in a sightline towards HD 76341. No [SUP]13[/SUP]CH[SUP]+[/SUP] is detected, placing a limit on the [SUP]13[/SUP]CH[SUP]+[/SUP] to [SUP]12[/SUP]CH[SUP]+[/SUP] ratio of ˜0.01. If a formal fit is attempted, the equivalent width ratio in the two isotopes is a factor ˜90 but with large errors

Practice makes perfect? Skillful performances in veterinary work

Is vetting a craft that must be learned owing to the limitations of scientific discipline, or simply a question of practice makes perfect? This question arose from our empirical research on veterinary surgeons (vets), who we found were often struggling with the divergence between the precise and unambiguous knowledge underlying the training and the unpredictability and imprecision of their everyday practices. These are comparatively underexplored issues insofar as the literature on vets tends to be descriptive and statistical, focusing primarily on clinical matters and associated human-animal interactions. Our cliché title has a question mark because while many vets remain embedded in the disciplined ‘certainties’ and causal regularities within their training, in practice this ordered world is rarely realized, and they are faced with indeterminacy where the ‘perfect’ solution eludes them. Vets often turn these unrealistic ideals of expertise back in on themselves, thus generating doubt and insecurity for any failure in their practices. In analysing vets’ experiences, we pay attention to the anatomical models of science, where linear causal analysis is expected to provide orderly and predictable outcomes or ‘right’ answers to problems, as well as notions of expertise that turn out to be illusory