Spectral optical monitoring of the double peaked emission line AGN Arp 102B: II. Variability of the broad line properties

We investigate a long-term (26 years, from 1987 to 2013) variability in the broad spectral line properties of the radio galaxy Arp 102B, an active galaxy with broad double-peaked emission lines. We use observations presented in Paper I (Shapovalova et al. 2013) in the period from 1987 to 2011, and a new set of observations performed in 2012--2013. To explore the BLR geometry, and clarify some contradictions about the nature of the BLR in Arp 102B we explore variations in the H$\alpha$ and H$\beta$ line parameters during the monitored period. We fit the broad lines with three broad Gaussian functions finding the positions and intensities of the blue and red peaks in H$\alpha$ and H$\beta$. Additionally we fit averaged line profiles with the disc model. We find that the broad line profiles are double-peaked and have not been changed significantly in shapes, beside an additional small peak that, from time to time can be seen in the blue part of the H$\alpha$ line. The positions of the blue and red peaks { have not changed significantly during the monitored period. The H$\beta$ line is broader than H$\alpha$ line in the monitored period. The disc model is able to reproduce the H$\beta$ and H$\alpha$ broad line profiles, however, observed variability in the line parameters are not in a good agreement with the emission disc hypothesis. It seems that the BLR of Arp 102B has a disc-like geometry, but the role of an outflow can also play an important role in observed variation of the broad line properties.Comment: 17 pages, Accepted for publication in A&

Ultra-short Period Binaries from the Catalina Surveys

We investigate the properties of 367 ultra-short period binary candidates selected from 31,000 sources recently identified from Catalina Surveys data. Based on light curve morphology, along with WISE, SDSS and GALEX multi-colour photometry, we identify two distinct groups of binaries with periods below the 0.22 day contact binary minimum. In contrast to most recent work, we spectroscopically confirm the existence of M-dwarf+M-dwarf contact binary systems. By measuring the radial velocity variations for five of the shortest-period systems, we find examples of rare cool-white dwarf+M-dwarf binaries. Only a few such systems are currently known. Unlike warmer white dwarf systems, their UV flux and their optical colours and spectra are dominated by the M-dwarf companion. We contrast our discoveries with previous photometrically-selected ultra-short period contact binary candidates, and highlight the ongoing need for confirmation using spectra and associated radial velocity measurements. Overall, our analysis increases the number of ultra-short period contact binary candidates by more than an order of magnitude.Comment: 12 pages, 12 figures, accepted Ap

Una propuesta metodológica para la evaluación del proceso de enseñanza-aprendizaje en un ambiente virtual

Key words: Assessment process, new information technologies, on line environment, student performanceAbstract. This article provides a methodological proposal oriented to optimize theassessment process of a student performance on an on line environment through the application of group communication techniques (advisor-student, student-advisor, studentstudent, student-chat and so on) and widespread use of the new technologies on information and telecommunication as basic tools, based one the process follow-up and statistical data collection from the student´s learning performance and behaviour to enable the construction of significant and reliable indexes thus allowing the advisor a diagnostic on the student´sattitude and performance, allowing him to take on time the adequate preventive/corrective decision measures based on a success/failure tests outputs from the student performance, on a day- to- day basis, on the line environment.Palabras claves: Aprovechamiento del alumno, entorno en línea, información tecnológica nueva, procesos de estimaciónResumen. Este artículo ofrece una propuesta metodológica enfocada a optimizar el proceso de evaluación sobre el aprovechamiento del alumno en un entorno en línea mediante técnicas de comunicación grupal (tutor- alumno, alumno-tutor, alumno-alumno, alumno-chat, programa, etc.) y el uso profuso de las nuevas tecnologías de información y telecomunicación como herramientas básicas, mediante un seguimiento y registro estadístico del aprovechamiento y actitudinal del estudiante, posibilitando así la construcción de índicessignificativos, seguros y confiables, que permitan al instructor/facilitador disponer de un diagnóstico sobre el comportamiento y actitud del aplicar y aplicar en consecuencia las medidas preventivas/correctivas sobre la conducta continuamente observada del alumno en el entorno en línea