A distance-limited sample of massive star-forming cores from the RMS survey

We analyse C18O (J = 3−2) data from a sample of 99 infrared (IR)-bright massive young stellar objects (MYSOs) and compact H ii regions that were identified as potential molecular-outflow sources in the Red MSX Source survey. We extract a distance-limited (D < 6 kpc) sample shown to be representative of star formation covering the transition between the source types. At the spatial resolution probed, Larson-like relationships are found for these cores, though the alternative explanation, that Larson's relations arise where surface-density-limited samples are considered, is also consistent with our data. There are no significant differences found between source properties for the MYSOs and H ii regions, suggesting that the core properties are established prior to the formation of massive stars, which subsequently have little impact at the later evolutionary stages investigated. There is a strong correlation between dust-continuum and C18O-gas masses, supporting the interpretation that both trace the same material in these IR-bright sources. A clear linear relationship is seen between the independently established core masses and luminosities. The position of MYSOs and compact H ii regions in the mass–luminosity plane is consistent with the luminosity expected from a cluster of protostars when using an ∼40 per cent star formation efficiency and indicates that they are at a similar evolutionary stage, near the end of the accretion phase

Shape Deformation driven Structural Transitions in Quantum Hall Skyrmions

The Quantum Hall ground state away from $\nu = 1$ can be described by a collection of interacting skyrmions. We show within the context of a nonlinear sigma model, that the classical ground state away from $\nu = 1$ is a skyrmion crystal with a generalized N\'eel order. We show that as a function of filling $\nu$, the skyrmion crystal undergoes a triangle to square to triangle transition at zero temperature. We argue that this structural transition, driven by a change in the shape of the individual skyrmions, is stable to thermal and quantum fluctuations and may be probed experimentally.Comment: 4 pages (REVTEX) and 4 .eps figure

Infall and outflow motions towards a sample of massive star-forming regions from the RMS survey

We present the results of an outflow and infall survey towards a distance-limited sample of 31 massive st ar-forming regions drawn from the Red MSX source (RMS) survey. The presence of young, active outflows is identified from SiO (8-7) emission and the infall dynamics are explored using HCO + /H 13 CO + (4-3) emission. We investigate if the infall and outflow parameters vary with source properties, exploring whether regions hosting potentially young active outflows show similarities or differences with regions harbouring more evolved, possibly momentum-driven, 'fossil' outflows. SiO emission is detected towards approximately 46 per cent of the sources. When considering sources with and without an SiO detection (i.e. potentially active and fossil outflows, respectively), only the 12 CO outflow velocity shows a significant difference between samples, indicating SiO is more prevalent towards sources with higher outflow velocities. Furthermore, we find the SiO luminosity increases as a function of the Herschel 70 μm to WISE 22 μm flux ratio, suggesting the production of SiO is prevalent in younger, more embedded regions. Similarly, we find tentative evidence that sources with an SiO detection have a smaller bolometric luminosity-to-mass ratio, indicating SiO (8-7) emission is associated with potentially younger regions. We do not find a prevalence towards sources displaying signatures of infall in our sample. However, the higher energy HCO + transitions may not be the best suited tracer of infall at this spatial resolution in these regions. © 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society

The RMS survey: ammonia mapping of the environment of massive young stellar objects

We present the results of ammonia observations towards 66 massive star forming regions identified by the Red Midcourse Space Experiment Source survey. We have used the Green Bank Telescope and the K-Band Focal Plane Array to map the ammonia (NH3) (1,1) and (2,2) inversion emission at a resolution of 30 arcsec in 8 arcmin regions towards the positions of embedded massive star formation. We have identified a total of 115 distinct clumps, approximately two-thirds of which are associated with an embedded massive young stellar object or compact H ii region, while the others are classified as quiescent. There is a strong spatial correlation between the peak NH3 emission and the presence of embedded objects. We derive the spatial distribution of the kinetic gas temperatures, line widths, and NH3 column densities from these maps, and by combining these data with dust emission maps we estimate clump masses, H2 column densities and ammonia abundances. The clumps have typical masses of ∼1000 M⊙ and radii ∼0.5 pc, line widths of ∼2 km s−1 and kinetic temperatures of ∼16–20 K. We find no significant difference between the sizes and masses of the star-forming and quiescent subsamples; however, the distribution maps reveal the presence of temperature and line width gradients peaking towards the centre for the star-forming clumps while the quiescent clumps show relatively uniform temperatures and line widths throughout. Virial analysis suggests that the vast majority of clumps are gravitationally bound and are likely to be in a state of global free fall in the absence of strong magnetic fields. The similarities between the properties of the two subsamples suggest that the quiescent clumps are also likely to form massive stars in the future, and therefore provide an excellent opportunity to study the initial conditions of massive pre-stellar and protostellar clumps

Family caregivers’ perspectives on their interaction and relationship with people living with dementia in a nursing home:A qualitative study

BACKGROUND: Social interactions are important for people living with dementia in a nursing home. However, not much is known about interactions and relationships between residents and family caregivers and related experiences of family caregivers. We aim to advance the knowledge on how family caregivers interact with people living with dementia in a nursing home and how they maintain or redesign a meaningful connection. METHODS: Qualitative research using interviews with family caregivers (n = 31) to explore perspectives on their interaction and relationship with the person living with dementia. Interviews were held during the reopening of nursing homes after the first COVID-19 lockdown in the Netherlands. In this situation, family caregivers became more aware of their interaction and relationship with the resident, which provided a unique opportunity to reflect on this. The interviews explored the interaction and relationship in a broad sense, not specifically for the COVID-19 situation. Thematic analysis was performed to analyze the data. RESULTS: We were able to identify three key themes reflecting the experiences of family caregivers: (1) changes in the interaction and relationship, (2) strategies to promote connection, and (3) appreciation of the interaction and relationship. From the viewpoint of family caregivers, the interaction and relationship are important for both the resident living with dementia and for themselves, and family caregivers have different strategies for establishing a meaningful connection. Nevertheless, some appear to experience difficulties with constructing such a connection with the resident. CONCLUSIONS: Our results provide a basis for supporting family caregivers in perceiving and establishing mutuality and reciprocity so that they can experience togetherness. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-022-02922-x

Maud JL Graff. Effectiveness and efficiency of community based occupational therapy for older people with dementia and their caregivers

bespreking proefschrift Maud JL Graff. Effectiveness and efficiency of community based occupational therapy for older people with dementia and their caregivers. Academisch proefschrift Radboud Universiteit Nijmegen, faculteit Medische Wetenschappen, 2008

Substructures in the Keplerian disc around the O-type (proto-)star G17.64+0.16

We present the highest angular resolution (̃20 × 15 mas-44 × 33 au) Atacama Large Millimeter/sub-millimeter Array (ALMA) observations that are currently possible of the proto-O-star G17.64+0.16 in Band 6. The Cycle 5 observations with baselines out to 16 km probe scales &lt; 50 au and reveal the rotating disc around G17.64+0.16, a massive forming O-type star. The disc has a ring-like enhancement in the dust emission that is especially visible as arc structures to the north and south. The Keplerian kinematics are most prominently seen in the vibrationally excited water line, H2O 55, 0-64, 3 ν2 = 1 (Eu = 3461.9 K). The mass of the central source found by modelling the Keplerian rotation is consistent with 45 ± 10 M☉. The H30α (231.9 GHz) radio-recombination line and the SiO (5-4) molecular line were detected at up to the ̃10σ level. The estimated disc mass is 0.6 - 2.6 M☉ under the optically thin assumption. Analysis of the Toomre Q parameter in the optically thin regime indicates that the disc stability is highly dependent on temperature. The disc currently appears stable for temperatures &gt; 150 K; this does not preclude that the substructures formed earlier through disc fragmentation. Data cubes of the source are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/qcat?J/A+A/627/L6

An Overview of the 2014 ALMA Long Baseline Campaign

A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from September to late November 2014, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.Comment: 11 pages, 7 figures, 2 tables; accepted for publication in the Astrophysical Journal Letters; this version with small changes to affiliation