Quiet Sun magnetic fields observed by Hinode: Support for a local dynamo

The Hinode mission has revealed copious amounts of horizontal flux covering the quiet Sun. Local dynamo action has been proposed to explain the presence of this flux. We sought to test whether the quiet Sun flux detected by Hinode is due to a local or the global dynamo by studying long-term variations in the polarisation signals detectable at the disc centre of the quiet Sun between November 2006 and May 2012, with particular emphasis on weak signals in the internetwork. The investigation focusses on line-integrated circular polarisation V_tot and linear polarisation LP_tot profiles obtained from the Fe I 6302.5 \AA absorption line in Hinode SOT/SP. Both circular and linear polarisation signals show no overall variation in the fraction of selected pixels from 2006 until 2012. There is also no variation in the magnetic flux in this interval of time. The probability density functions (PDF) of the line-of-sight magnetic flux can be fitted with a power law from 1.17 x 10^17 Mx to 8.53 x 10^18 Mx with index \alpha=-1.82 \pm 0.02 in 2007. The variation of \alpha 's across all years does not exceed a significance of 1\sigma. Linearly polarised features are also fitted with a power law, with index \alpha=-2.60 \pm 0.06 in 2007. Indices derived from linear polarisation PDFs of other years also show no significant variation. Our results show that the ubiquitous horizontal polarisation on the edges of bright granules seen by Hinode are invariant during the minimum of cycle 23. This supports the notion that the weak circular and linear polarisation is primarily caused by an independent local dynamo

Two types of S phase precipitates in Al-Cu-Mg alloys

Transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) have been used to study S phase precipitation in an Al-4.2Cu-1.5Mg-0.6Mn-0.5Si (AA2024) and an Al-4.2Cu-1.5Mg-0.6Mn-0.08Si (AA2324) (wt-%) alloy. In DSC experiments on as solution treated samples two distinct exothermic peaks are observed in the range 250 to 350°C, whereas only one peak is observed in solution treated and subsequently stretched or cold worked samples. Samples heated to 270°C and 400°C at a rate of 10°C/min in the DSC have been studied by TEM. The selected area diffraction patterns show that S phase precipitates with the classic orientation relationship form during the lower temperature peak, and for the solution treated samples, the higher temperature peak is caused by the formation of a second type of S phase precipitates which have an orientation relationship that is rotated by ~4 degrees to the classic one. The effects of Si and cold work on the formation of second type of S precipitates have been discussed

The variability of the Crab Nebula in radio: No radio counterpart to gamma-ray flares

We present new Jansky Very Large Array (VLA) radio images of the Crab Nebula at 5.5 GHz, taken at two epochs separated by 6 days about two months after a gamma-ray flare in 2012 July. We find no significant change in the Crab's radio emission localized to a region of <2 light-months in radius, either over the 6-day interval between our present observations or between the present observations and ones from 2001. Any radio counterpart to the flare has a radio luminosity of <~ $2 \times 10^{-4}$ times that of the nebula. Comparing our images to one from 2001, we do however find changes in radio brightness, up to 10% in amplitude, which occur on decade timescales throughout the nebula. The morphology of the changes is complex suggesting both filamentary and knotty structures. The variability is stronger, and the timescales likely somewhat shorter, nearer the centre of the nebula. We further find that even with the excellent uv~coverage and signal-to-noise of the VLA, deconvolution errors are much larger than the noise, being up to 1.2% of peak brightness of the nebula in this particular case.Comment: Accepted to MNRAS; 13 pages, 6 figure

Systematic search for high-energy gamma-ray emission from bow shocks of runaway stars

Context. It has been suggested that the bow shocks of runaway stars are sources of high-energy gamma rays (E > 100 MeV). Theoretical models predicting high-energy gamma-ray emission from these sources were followed by the first detection of non-thermal radio emission from the bow shock of BD+43^\deg 3654 and non-thermal X-ray emission from the bow shock of AE Aurigae. Aims. We perform the first systematic search for MeV and GeV emission from 27 bow shocks of runaway stars using data collected by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope (Fermi). Methods. We analysed 57 months of Fermi-LAT data at the positions of 27 bow shocks of runaway stars extracted from the Extensive stellar BOw Shock Survey catalogue (E-BOSS). A likelihood analysis was performed to search for gamma-ray emission that is not compatible with diffuse background or emission from neighbouring sources and that could be associated with the bow shocks. Results. None of the bow shock candidates is detected significantly in the Fermi-LAT energy range. We therefore present upper limits on the high-energy emission in the energy range from 100 MeV to 300 GeV for 27 bow shocks of runaway stars in four energy bands. For the three cases where models of the high-energy emission are published we compare our upper limits to the modelled spectra. Our limits exclude the model predictions for Zeta Ophiuchi by a factor $\approx$ 5.Comment: 5 pages, 5 figures, 1 table, accepted by A&

Collaborative organizational infrastructures to support open access journals

With the advancement of open access (OA) journal publishing opportunities in partnership with presses and faculty, libraries in alignment with intersecting academic values are fulfilling a need by supporting sustainable models of scholarly communication that incorporate disseminating faculty scholarship in collaboration with library and/or press staff and editors to “start up” an OA journal or transform an existing print journal to OA. Library staff that embrace faculty or student publishing partnerships are structuring and utilizing their scholarly communication skill sets by positioning the availability of open access publications to disseminate quality research results. University presses are also forging alliances with libraries to strategically align their business models as an economically viable solution and compelling competitor in publishing journals. The peer-reviewed OA journal model actuates library publishing activities with the goals of making research globally visible, the ability to build upon others’ work, and uphold the scholarly communication practices of researchers and publishers that might include stakeholder ways in: supporting the faculty research cycle; hosting software and tools’ training; metadata creation; database indexing; Creative Commons licensing; reducing libraries’ purchasing costs; engaging altmetrics; and economic viability. My infographic poster will visually depict various stakeholder alignments in publishing OA journals

Where is the library in course management software?

Course management software (CMS) or courseware products, such as Prometheus, FirstClass, Blackboard, and WebCT, do not include the Library as an essential, curricular component in their design. Consequently, the task falls to librarians to creatively partner with faculty to input library resources into courseware to support students effectively in their research endeavors. Distance learning students, who are off campus, will benefit as they are physically removed from the Library. Distance learners (DLs) can be intimidated by library websites and find it difficult and time consuming to navigate. Since the entire course content is in the course management product, the primary source for class information, it makes good sense to include library resources and services in the appropriate areas, such as the syllabus, assignments, projects, etc. Including research resources within courseware enables students to get started on their own in navigating the Library and can provide direct contact information to appropriate library staff for further and deeper resource assistance

Collaborating with faculty to start up an open access journal

University faculty have ongoing pressure to publish their research findings and teaching successes and produce scholarship worthy of tenure. Acceptance to publish an article in a journal can be highly competitive and in some fields of study, there are few journal publication options. With the advent of open access (OA) publishing opportunities, academic libraries are fulfilling a need by supporting sustainable models of scholarly communication that include collaborating with faculty and editors to “start up” an OA journal or convert a traditional print journal to OA. Some faculty would prefer to transcend the traditional publishing model and may not be aware of available OA publishing opportunities or know the route to become a journal editor. Libraries can provide additional support for faculty to “spin a new journal into the gold publishing model” and transcend an existing print journal into the “green model” of a sustainable OA publication