365 research outputs found

    The Massive and Distant Clusters of WISE Survey V: Extended Radio Sources in Massive Galaxy Clusters at z~1

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    We present the results from a pilot study with the Karl G. Jansky Very Large Array (JVLA) to determine the radio morphologies of extended radio sources and the properties of their host-galaxies in 10 massive galaxy clusters at z~1, an epoch in which clusters are assembling rapidly. These clusters are drawn from a parent sample of WISE-selected galaxy clusters that were cross-correlated with the VLA Faint Images of the Radio Sky at Twenty-Centimeters survey (FIRST) to identify extended radio sources within 1ā€²^{\prime} of the cluster centers. Out of the ten targeted sources, six are FR II sources, one is an FR I source, and three sources have undetermined morphologies. Eight radio sources have associated Spitzer data, 75% presenting infrared counterparts. A majority of these counterparts are consistent with being massive galaxies. The angular extent of the FR sources exhibits a strong correlation with the cluster-centric radius, which warrants further investigation with a larger sample.Comment: accepted to Ap

    ā€œSheā€™s been a rockā€: the function and importance of ā€˜holdingā€™ by social prescribing link workers in primary care in England: findings from a realist evaluation.

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    Social prescribing link workers are new roles in English primary care. One of their intended functions is to address the increasing number of patients with conditions influenced by the wider, social determinants of health. Their main purpose is to connect people to community resources to meet their non-medical needs. However, our research reveals that link workers provide not only connections, but also what we have described as ā€˜holdingā€™ for patients who have complex needs, who lack informal networks of support or who are waiting to access services. We explore the concept of holding, its meaning and significance in this context and its consequences.As part of a realist evaluation, we observed seven link workers in GP practices in England during focussed ethnographies over a three-week period. We took field notes and interviewed 61 patients and 93 healthcare professionals. Nine to twelve months later we carried out follow-up interviews with 41 patients, seven link workers and a link worker manager. We identified four functions of holding: supporting patients waiting for services, sustaining patients as they prepare for change, reducing the emotional burden of primary healthcare professionals, and bearing witness to patientsā€™ distress. Holding appears to be a vital, but often overlooked aspect of social prescribing. Patients benefit from having a reliable and consistent person to support their emotional needs. However, similar to the impact of holding on other primary care professionals, there are unintended consequences: some link workers exceed their capacity, become over-burdened, experience burnout, and leave their job. Recognizing the importance of holding and understanding its role in link workers' primary care responsibilities are critical. If holding work is accepted as a role for link workers, providing training and support for them should be prioritized to ensure successful implementation and positive outcomes for patients, link workers and primary healthcare

    Observation of Parity Nonconservation in Moller Scattering

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    We report a measurement of the parity-violating asymmetry in fixed target electron-electron (Moller) scattering: A_PV = -175 +/- 30 (stat.) +/- 20 (syst.) parts per billion. This first direct observation of parity nonconservation in Moller scattering leads to a measurement of the electron's weak charge at low energy Q^e_W = -0.053 +/- 0.011. This is consistent with the Standard Model expectation at the current level of precision: sin^2\theta_W(M_Z)_MSbar = 0.2293 +/- 0.0024 (stat.) +/- 0.0016 (syst.) +/- 0.0006 (theory).Comment: Version 3 is the same as version 2. These versions contain minor text changes from referee comments and a change in the extracted value of Q^e_W and sin^2\theta_W due to a change in the theoretical calculation of the bremsstrahulung correction (ref. 16

    The Era of Star Formation in Galaxy Clusters

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    We analyze the star formation properties of 16 infrared-selected, spectroscopically confirmed galaxy clusters at 1 1.35. Using infrared luminosities measured with deep Spitzer/Multiband Imaging Photometer for Spitzer observations at 24 Ī¼m, along with robust optical + IRAC photometric redshifts and spectral-energy-distribution-fitted stellar masses, we present the dust-obscured star-forming fractions, star formation rates, and specific star formation rates in these clusters as functions of redshift and projected clustercentric radius. We find that z ~ 1.4 represents a transition redshift for the ISCS sample, with clear evidence of an unquenched era of cluster star formation at earlier times. Beyond this redshift, the fraction of star-forming cluster members increases monotonically toward the cluster centers. Indeed, the specific star formation rate in the cores of these distant clusters is consistent with field values at similar redshifts, indicating that at z > 1.4 environment-dependent quenching had not yet been established in ISCS clusters. By combining these observations with complementary studies showing a rapid increase in the active galactic nucleus (AGN) fraction, a stochastic star formation history, and a major merging episode at the same epoch in this cluster sample, we suggest that the starburst activity is likely merger-driven and that the subsequent quenching is due to feedback from merger-fueled AGNs. The totality of the evidence suggests we are witnessing the final quenching period that brings an end to the era of star formation in galaxy clusters and initiates the era of passive evolution
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