HARP/ACSIS: A submillimetre spectral imaging system on the James Clerk Maxwell Telescope

This paper describes a new Heterodyne Array Receiver Programme (HARP) and Auto-Correlation Spectral Imaging System (ACSIS) that have recently been installed and commissioned on the James Clerk Maxwell Telescope (JCMT). The 16-element focal-plane array receiver, operating in the submillimetre from 325 to 375 GHz, offers high (three-dimensional) mapping speeds, along with significant improvements over single-detector counterparts in calibration and image quality. Receiver temperatures are $\sim$120 K across the whole band and system temperatures of $\sim$300K are reached routinely under good weather conditions. The system includes a single-sideband filter so these are SSB figures. Used in conjunction with ACSIS, the system can produce large-scale maps rapidly, in one or more frequency settings, at high spatial and spectral resolution. Fully-sampled maps of size 1 square degree can be observed in under 1 hour. The scientific need for array receivers arises from the requirement for programmes to study samples of objects of statistically significant size, in large-scale unbiased surveys of galactic and extra-galactic regions. Along with morphological information, the new spectral imaging system can be used to study the physical and chemical properties of regions of interest. Its three-dimensional imaging capabilities are critical for research into turbulence and dynamics. In addition, HARP/ACSIS will provide highly complementary science programmes to wide-field continuum studies, and produce the essential preparatory work for submillimetre interferometers such as the SMA and ALMA.Comment: MNRAS Accepted 2009 July 2. 18 pages, 25 figures and 6 table

The JCMT Gould Belt Survey: constraints on prestellar core properties in Orion A North

We employ SCUBA-2 (Submillimetre Common-User Bolometer Array 2) observations of the Orion A North molecular cloud to derive column density and temperature maps. We apply a novel, Hessian-based structural identification algorithm for detection of prestellar cores to these data, allowing for automated generation of the prestellar mass function. The resulting mass function is observed to peak at $1.39^{+0.18}_{{-}0.19} M_{\odot}$, indicating a star-forming efficiency lower limit of ∼14 per cent when compared with the Orion nebula Cluster initial mass function (IMF) peak. Additionally, the prestellar mass function is observed to decay with a high-mass powerlaw exponent $\alpha = 2.53^{+0.16}_{{-}0.14}$, indicating approximate functional similarity with the Salpeter IMF ($\alpha = 2.35$). This result, when combined with the results of previous investigations suggests a regional dependence of the star-forming efficiency

The JCMT Gould Belt Survey: evidence for radiative heating and contamination in the W40 complex

We present SCUBA-2 450 μm and 850 μm observations of the W40 complex in the Serpens-Aquila region as part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) of nearby star-forming regions. We investigate radiative heating by constructing temperature maps from the ratio of SCUBA-2 fluxes using a fixed dust opacity spectral index, β = 1.8, and a beam convolution kernel to achieve a common 14.8 arcsec resolution. We identify 82 clumps ranging between 10 and 36 K with a mean temperature of 20 ± 3 K. Clump temperature is strongly correlated with proximity to the external OB association and there is no evidence that the embedded protostars significantly heat the dust. We identify 31 clumps that have cores with densities greater than 105cm-3. 13 of these cores contain embedded Class 0/I protostars. Many cores are associated with bright-rimmed clouds seen in Herschel 70 μm images. From JCMT HARP observations of the 12CO 3-2 line, we find contamination of the 850 μm band of up to 20 per cent. We investigate the free-free contribution to SCUBA-2 bands from large-scale and ultracompact HII regions using archival VLA data and find the contribution is limited to individual stars, accounting for 9 per cent of flux per beam at 450 μm or 12 per cent at 850 μm in these cases. We conclude that radiative heating has potentially influenced the formation of stars in the Dust Arc sub-region, favouring Jeans stable clouds in the warm east and fragmentation in the cool west

The JCMT Gould Belt Survey: SCUBA-2 Data Reduction Methods and Gaussian Source Recovery Analysis

The James Clerk Maxwell Telescope (JCMT) Gould Belt Survey (GBS) was one of the first legacy surveys with the JCMT in Hawaii, mapping 47 deg2 of nearby (<500 pc) molecular clouds in dust continuum emission at 850 and 450 μm, as well as a more limited area in lines of various CO isotopologues. While molecular clouds and the material that forms stars have structures on many size scales, their larger-scale structures are difficult to observe reliably in the submillimeter regime using ground-based facilities. In this paper, we quantify the extent to which three subsequent data reduction methods employed by the JCMT GBS accurately recover emission structures of various size scales, in particular, dense cores, which are the focus of many GBS science goals. With our current best data reduction procedure, we expect to recover 100% of structures with Gaussian σ sizes of ≤30'' and intensity peaks of at least five times the local noise for isolated peaks of emission. The measured sizes and peak fluxes of these compact structures are reliable (within 15% of the input values), but source recovery and reliability both decrease significantly for larger emission structures and fainter peaks. Additional factors such as source crowding have not been tested in our analysis. The most recent JCMT GBS data release includes pointing corrections, and we demonstrate that these tend to decrease the sizes and increase the peak intensities of compact sources in our data set, mostly at a low level (several percent), but occasionally with notable improvement

Inspiring hope through sources of strength among predominantly Pacific Islander communities

in the world for youth, taking a tremendous toll on local communities (Else et al., 2007; Goebert, 2014). Comprehension of community perspectives of suicide and well-being can enhance suicide prevention interventions. This community-initiated project aimed to culturally adapt the components of an evidence-based youth suicide prevention intervention and refine the intervention methodology to align with these adaptations. Formative qualitative work was conducted with community members to obtain information on community strengths and program fit. Narrative analyses were emergent and emphasized components for suicide prevention, incorporating cultural auditing to ensure information reflected group views. Participants highlighted cultural aspects pertaining to the program philosophy, the importance of cultural protocol, local innovation in suicide prevention, and culturally grounded advancements that give back to their community. This insight was applied to two adjacent but distinct communities to integrate suicide prevention in a sustainable way by culturally adapting the program. Effective suicide prevention for rural and Indigenous youth requires a broad-based community commitment, connection, and network.  

Effect of a Telephone-Based Lifestyle Intervention on Weight, Body Composition, and Metabolic Biomarkers in Rural Ohio: Results from a Randomized Pilot Study

Rural residents experience higher rates of obesity, obesity-related chronic diseases, and poorer lifestyle. Promoting physical activity and healthy eating are critical for rural residents; however, lack of resources and access barriers limit the feasibility of in-person lifestyle interventions. There is a need to design and deliver remotely accessible lifestyle interventions in this population. This pilot study examined the effect of a telephone-based lifestyle intervention on weight, body composition, lipids, and inflammatory biomarkers among rural Ohio residents. Rural Ohio adults with overweight/obesity (n = 40) were 2:1 randomized to a 15-week telephone-based lifestyle intervention (n = 27) or control group (n = 13). The lifestyle intervention group received weekly telephone counseling sessions emphasizing healthy eating and increasing physical activity. The control group received educational brochures describing physical activity and dietary recommendations. Weight, body composition, fasting blood lipids, and inflammatory biomarkers were objectively measured at baseline and 15 weeks at local community centers (trial registration#: NCT05040152 at ClinicalTrial.gov). Linear mixed models were used to examine change over time by group. Participants were mostly female, with an average age of 49 years. Over the 15-week trial, the lifestyle intervention showed superior improvements in total cholesterol (∆ = −18.7 ± 7.8 mg/dL, p = 0.02) and LDL (∆ = −17.1 ± 8.1 mg/dL, p = 0.04) vs. control, whereas no significant between-group differences in weight, body composition, or inflammation were observed. Our findings suggest that a 15-week telephone-based lifestyle intervention may offer metabolic benefits that reduce disease risk in rural adults with obesity. Future large-scale studies are needed to determine the efficacy of remotely accessible lifestyle interventions in rural populations, with the goal of reducing obesity-related disparities