RXTE and ASCA Constraints on Non-thermal Emission from the A2256 Galaxy Cluster

An 8.3 hour observation of the Abell 2256 galaxy cluster using the Rossi X-ray Timing Explorer proportional counter array produced a high quality spectrum in the 2 - 30 keV range. Joint fitting with the 0.7 - 11 keV spectrum obtained with the Advanced Satellite for Astrophysics and Cosmology gas imaging spectrometer gives an upperlimit of 2.3x10^-7 photons/cm^2/sec/keV for non-thermal emission at 30 keV. This yields a lower limit to the mean magnetic field of 0.36 micro Gauss (uG) and an upperlimit of 1.8x10^-13 ergs/cm^3 for the cosmic-ray electron energy density. The resulting lower limit to the central magnetic field is ~1 - 3 uG While a magnetic field of ~0.1 - 0.2 uG can be created by galaxy wakes, a magnetic field of several uG is usually associated with a cooling flow or, as in the case of the Coma cluster, a subcluster merger. However, for A2256, the evidence for a merger is weak and the main cluster shows no evidence of a cooling flow. Thus, there is presently no satisfactory hypothesis for the origin of an average cluster magnetic field as high as >0.36 uG in the A2256 cluster.Comment: 8 pages, Astrophysical Journal (in press

A Puzzling Merger in A3266: the Hydrodynamic Picture from XMM-Newton

Using the mosaic of nine XMM-Newton observations, we study the hydrodynamic state of the merging cluster of galaxies Abell 3266. The high quality of the spectroscopic data and large field of view of XMM-Netwon allow us to determine the thermodynamic conditions of the intracluster medium on scales of order of 50 kpc. A high quality entropy map reveals the presence of an extended region of low entropy gas, running from the primary cluster core toward the northeast along the nominal merger axis. The mass of the low entropy gas amounts to approximately 2e13 solar masses, which is comparable to the baryonic mass of the core of a rich cluster. We test the possibility that the origin of the observed low entropy gas is either related to the disruption a preexisting cooling core in Abell 3266 or to the stripping of gas from an infalling subcluster companion. We find that both the radial pressure and entropy profiles as well as the iron abundance of Abell 3266 do not resemble those in other known cooling core clusters (Abell 478). Thus we conclude that the low entropy region is subcluster gas in the process of being stripped off from its dark matter halo. In this scenario the subcluster would be falling onto the core of A3266 from the foreground. This would also help interpret the observed high velocity dispersion of the galaxies in the cluster center, provided that the mass of the subcluster is at most a tenth of the mass of the main cluster.Comment: 6 pages, ApJ sub

Teachers’ Perceptions of a Multiple High-Risk Behavior Prevention Program and Delivery of Universal Programming

Much of the success of high-risk behavior prevention programs rests with teachers who deliver the curriculum however; few studies have investigated teachers\u27 perceptions of program implementation. The objective of this phenomenological study was to answer the question, “What are the experiences of teachers who are asked to be involved in the implementation process when their school adopts a multiple high-risk behavior prevention program”? Participants included 10 teachers at a local, private high school in the Southern United States. Five themes emerged: (a) lack of consistent historical effort, (b) need for program, (c) positive but tentative perceptions, (d) challenges with implementation, and (e) review of program counselor. The qualitative results identified factors that can promote or hinder success of the program

Una transcripción de la entonación del dialecto jerezano de Andalucía, España

Dialect variation in intonation is a widely attested phenomenon in the crosslinguistic literature (see Warren 2005a) and also in the literature on Spanish (Prieto & Roseano 2010, Sosa 1999). Prieto and Roseano (2010) provide an edited volume on the transcription of Spanish intonation for ten different dialects of the language. Two of these chapters characterize the intonation of Spanish spoken in northern and central Spain, but no information is offered on varieties spoken in the southern Andalusia area. This paper is designed to fill this gap in the literature as it investigates the acoustic properties of a series of F0 contours produced in an intonation survey by nine speakers from Jerez de la Frontera, a coastal city located in the southwest province of Cádiz, Spain. Speech data were analyzed in Praat (Boersma & Weenink 2011) following the original Sp_ToBI transcription system (Beckman, Díaz-Campos, McGory, & Morgan 2002) and the revised system put forth in Estebas-Vilaplana and Prieto (2008). Results show that neutral and biased statements were communicated by the L* L% vs. L+H* L% contrast, respectively. Confirmation questions show a variety of patterns based on the speaker’s belief of the proposition in question. Two configurations are possible for informationseeking wh-questions, H+L* L% and L+¡H* L%. Commands are the only pragmatic intent for which the M% boundary tone is used, and vocatives are characterized by L+H* HL% in neutral and marked intents. Although Jerezano Andalusian speakers share intonational characteristics with other varieties of European and American Spanish, there are important differences that motivate a thorough investigation of this language variety. Finally, dialect comparisons are provided to achieve a more comprehensive account of intonational variation in Spanish.La variación dialectal de la entonación es un fenómeno ampliamente corroborado en la literatura especializada en el análisis lingüístico de las lenguas (ver Warren 2005a) así como en múltiples publicaciones sobre el español (Prieto & Roseano 2010, Sosa 1999). Prieto y Roseano (2010) ofrecen un volumen editado sobre la transcripción de la entonación española de diez dialectos diferentes. Aunque dos de estos capítulos especifican la entonación del español peninsular en las zonas norte y central, no se aporta ninguna información sobre las variedades habladas en el sur de Andalucía. Este proyecto está diseñado para suplir esta carencia y de este modo, ofrecer una investigación sobre las propiedades acústicas de una serie de contornos F0 producidos en una encuesta entonativa realizada por 9 hablantes de Jerez de la Frontera, ciudad localizada al suroeste de la provincia de Cádiz, España. Los datos de producción oral fueron analizados con Praat (Boersma & Weenink 2011) siguiendo tanto el sistema de transcripción para Sp_ToBI (Beckman, Díaz- Campos, McGory, & Morgan 2002), como el sistema revisado de Estebas- Vilaplana y Prieto (2008). Los resultados muestran que las afirmaciones neutrales y no neutrales se produjeron mediante el contraste L* L% vs. L+H* L% respectivamente. En cuanto a las preguntas de confirmación, éstas muestran una variedad de patrones basados en la creencia que el hablante tiene de la pregunta en cuestión. Sobre las preguntas QU (o pronominales), dos configuraciones resultaron posibles: H+L* L% y L+¡H* L%. Las órdenes resultaron ser la única intención pragmática para las que se usa la frontera tonal M%, y por último, los vocativos se produjeron mediante L+H* HL% en intenciones de habla neutrales y marcadas. Aunque los hablantes del acento jerezano del andaluz comparten características entonativas con otras variedades del español europeo y americano, hay diferencias importantes que motivan una investigación profunda de esta variedad. Por último, se proporcionan comparaciones dialectales con la intención de conseguir una explicación más completa de la variación entonativa del español

Leaders and Recruiters from the Next Generation: A Phenomenological Study

Studies involving student ambassadors have demonstrated their significance in recruiting prospective students to universities and colleges but they have not included the perceptions of the student ambassadors themselves. The purpose of this phenomenological study was to describe the perceptions and experiences of students who served as student ambassadors for their educational institution. Fifteen student ambassadors provided individual descriptions of their perceptions of being an ambassador. Four themes provided a description of ambassadors’ perceptions: (a) belonging, (b) personal growth, (c) diversity, and (d) recruitment. A discussion of the benefits of student ambassadors as leaders are presented in terms of their ability to recruit for the university and college as well as the impact being a leader has on the ambassadors themselves