The two-component giant radio halo in the galaxy cluster Abell 2142

We report on a spectral study at radio frequencies of the giant radio halo in A2142 (z=0.0909), which we performed to explore its nature and origin. A2142 is not a major merger and the presence of a giant radio halo is somewhat surprising. We performed deep radio observations with the GMRT at 608 MHz, 322 MHz, and 234 MHz and with the VLA in the 1-2 GHz band. We obtained high-quality images at all frequencies in a wide range of resolutions. The radio halo is well detected at all frequencies and extends out to the most distant cold front in A2142. We studied the spectral index in two regions: the central part of the halo and a second region in the direction of the most distant south-eastern cold front, selected to follow the bright part of the halo and X-ray emission. We complemented our observations with a preliminary LOFAR image at 118 MHz and with the re-analysis of archival VLA data at 1.4 GHz. The two components of the radio halo show different observational properties. The central brightest part has higher surface brightess and a spectrum whose steepness is similar to those of the known radio halos, i.e. $\alpha^{\rm 1.78~GHz}_{\rm 118~MHz}=1.33\pm 0.08$. The ridge, which fades into the larger scale emission, is broader in size and has considerably lower surface brightess and a moderately steeper spectrum, i.e. $\alpha^{\rm 1.78~GHz}_{\rm 118~MHz}\sim 1.5$. We propose that the brightest part of the radio halo is powered by the central sloshing in A2142, similar to what has been suggested for mini-halos, or by secondary electrons generated by hadronic collisions in the ICM. On the other hand, the steeper ridge may probe particle re-acceleration by turbulence generated either by stirring the gas and magnetic fields on a larger scale or by less energetic mechanisms, such as continuous infall of galaxy groups or an off-axis merger.Comment: 18 pages, 10 figures, 4 tables - A&A, accepte

Improved kinematic options in ALEGRA.

Algorithms for higher order accuracy modeling of kinematic behavior within the ALEGRA framework are presented. These techniques improve the behavior of the code when kinematic errors are found, ensure orthonormality of the rotation tensor at each time step, and increase the accuracy of the Lagrangian stretch and rotation tensor update algorithm. The implementation of these improvements in ALEGRA is described. A short discussion of issues related to improving the accuracy of the stress update procedures is also included

Being Warm Being Happy: fuel poverty and adults with intellectual disabilities

Self-determination has been acknowledged as a criticalconstruct for people with intellectual disability (ID), given the benefits itspromotion entails towards an enhanced quality of life..

The political identities of neighbourhood planning in England

The rise of neighbourhood planning has been characterised as another step in a remorseless de-politicisation of the public sphere. A policy initiated by the Coalition Government in England to create the conditions for local communities to support housing growth, neighbourhood planning appears to evidence a continuing retreat from political debate and contestation. Clear boundaries are established for the holistic integration of participatory democracy into the strategic plan-making of the local authority. These boundaries seek to take politics out of development decisions and exclude all issues of contention from discussion. They achieve this goal at the cost of arming participatory democracy with a collective identity around which new antagonisms may develop. Drawing on the post-political theories of Chantal Mouffe this paper identifies the return of antagonism and conflict to participation in spatial planning. Key to its argument is the concept of the boundary or frontier that in Mouffe’s theoretical framework institutionalises conflict between political entities. Drawing on primary research with neighbourhood development plans in England the paper explores how boundary conditions and boundary designations generate antagonism and necessitate political action. The paper charts the development of the collective identities that result from these boundary lines and argues for the potential for neighbourhood planning to restore political conflict to the politics of housing development

Affective and evaluative responses to pop music

From reviews published in the “serious” pop music press, twenty recordings were selected which had received consistently favourable appraisals on affective and evaluative bases. A further twenty recordings were selected on the basis of high levels of chart performance but a lack of critical acclaim. Sixty-four subjects rated representative excerpts of these recordings on 11-point scales of either liking or artistic merit. The results indicated significantly lower liking and artistic merit ratings of critically praised excerpts; a positive liking-artistic merit correlation; and some “fragmentation” between affective and evaluative responses. The apparent discrepancy between the attitudes of the music press and subjects' ratings is discussed in terms of the availability and sophistication of evaluation cues