Solar Ca II K plage regions as proxies for magnetic fields of solar like stars

Solar plage regions can be observed directly, whereas plage regions as well as star-spots on solar like stars, can only be detected via their contribution to spectral irradiances of these stars. Such a spectral irradiance can be modelled by fractions belonging to the quiet star, the plage regions, and the star-spots. The idea is, to measure these fractions as well as the intensity enhancement due to plage regions on our Sun and then use this information to be able to model solar like stars. We verify the close connection between the size of the plage regions and the luminosity of the Sun, given by a correlation coefficient of 0.822. The size of the plage regions varies from 0%, when the Sun is very quiet, up to 2.7% for a more active Sun (a complete solar cycle is not yet analysed and hence our study does not contain an activity maximum). The used data sets are full-disc images taken by the RISE/PSPT instrument during the period from 2005 to 2012, at the MLSO

Parallelization of the SIR code

A high-resolution 3-dimensional model of the photospheric magnetic field is essential for the investigation of small-scale solar magnetic phenomena. The SIR code is an advanced Stokes-inversion code that deduces physical quantities, e.g. magnetic field vector, temperature, and LOS velocity, from spectropolarimetric data. We extended this code by the capability of directly using large data sets and inverting the pixels in parallel. Due to this parallelization it is now feasible to apply the code directly on extensive data sets. Besides, we included the possibility to use different initial model atmospheres for the inversion, which enhances the quality of the results

Migrating Home Computer Audio Waveforms to Digital Objects: A Case Study on Digital Archaeology

Rescuing data from inaccessible or damaged storage media for the purpose of preserving the digital data for the long term is one of the dimensions of digital archaeology. With the current pace of technological development, any system can become obsolete in a matter of years and hence the data stored in a specific storage media might not be accessible anymore due to the unavailability of the system to access the media. In order to preserve digital records residing in such storage media, it is necessary to extract the data stored in those media by some means.One early storage medium for home computers in the 1980s was audio tape. The first home computer systems allowed the use of standard cassette players to record and replay data. Audio cassettes are more durable than old home computers when properly stored. Devices playing this medium (i.e. tape recorders) can be found in working condition or can be repaired, as they are usually made out of standard components. By re-engineering the format of the waveform and the file formats, the data on such media can then be extracted from a digitised audio stream and migrated to a non-obsolete format.In this paper we present a case study on extracting the data stored on an audio tape by an early home computer system, namely the Philips Videopac+ G7400. The original data formats were re-engineered and an application was written to support the migration of the data stored on tapes without using the original system. This eliminates the necessity of keeping an obsolete system alive for enabling access to the data on the storage media meant for this system. Two different methods to interpret the data and eliminate possible errors in the tape were implemented and evaluated on original tapes, which were recorded 20 years ago. Results show that with some error correction methods, parts of the tapes are still readable even without the original system. It also implies that it is easier to build solutions while original systems are still available in a working condition

Calculations of periodicity from H<i>α</i> profiles of Proxima Centauri

We investigate retrieval of the stellar rotation signal for Proxima Centauri. We make use of high-resolution spectra taken with UVES and HARPS of Proxima Centauri over a 13-yr period as well as photometric observations of Proxima Centauri from ASAS and HST. We measure the Hα equivalent width and Hα index, skewness and kurtosis and introduce a method that investigates the symmetry of the line, the peak ratio, which appears to return better results than the other measurements. Our investigations return a most significant period of 82.6 ± 0.1 days, confirming earlier photometric results and ruling out a more recent result of 116.6 days which we conclude to be an alias induced by the specific HARPS observation times. We conclude that whilst spectroscopic Hα measurements can be used for period recovery, in the case of Proxima Centauri the available photometric measurements are more reliable. We make 2D models of Proxima Centauri to generate simulated Hα, finding that reasonable distributions of plage and chromospheric features are able to reproduce the equivalent width variations in observed data and recover the rotation period, including after the addition of simulated noise and flares. However the 2D models used fail to generate the observed variety of line shapes measured by the peak ratio. We conclude that only 3D models which incorporate vertical motions in the chromosphere can achieve this

New insights into the temporal evolution of MBPs

Magnetic bright points (MBPs) are among the most fascinating and interesting manifestations of small-scale solar magnetic fields. In the present work the temporal evolution of MBPs is followed in data sets taken by the Hinode satellite. The analysed data and obtained results confirm a recently presented study done with Sunrise/IMaX data, namely that MBPs are features undergoing fast evolution with magnetic fields starting around the equipartition field strength, then showing strong downflows (between 2 to 4 km/s) causing the magnetic field to amplify into the kG range (700 to 1500 G) before dissolving again. Furthermore the initial field inclinations depend on the initial magnetic field strengths and show an evolution with more vertical angles at some point during the evolution

Myth or Reality? New Modes of Governance and Environmental Enlargement in Hungary, Poland and Romania

This paper contrasts expectations derived from the theoretical literature on emergence of new modes of governance with empirical evidence, using data from empirical research on the adoption of and adaptation to EU environmental legislation during the EU accession process. The theoretical literature suggests that the huge costs implied by the compliance with EU directives and the weak state capacities available in the accession countries would encourage the emergence of new modes of governance. Empirical evidence from Hungary, Poland and Romania, however, shows that this is not the case. Institutional legacies, the simultaneity of transition and accession, and the time pressure to transfer the demanding EU regulations partially explain this observation. Most importantly, this paper finds that cooperation is most likely in those cases where at least a certain level of capacities is available to authorities, enabling them to remain in charge of the policy process

Gesellschaftspolitische und sozioökonomische Dimensionen ausgewählter Lieder zu Istanbul

Die vorliegende Arbeit beschäftigt sich mit einem kurdischen und sieben türkischen Liedern, die sich auf einen Zeitraum zwischen zweiter Hälfte des 20. Jh.s und der Gegenwart verteilen. Es wurde eine Auswahl an Musikstücken getroffen, die in ihren Texten die Stadt Istanbul aus einer kritischen Perspektive heraus betrachten und dadurch Einblicke in verschiedene Aspekte der modernen Türkei geben, die sich auf gesellschaftspolitische und sozioökonomische Spannungen beziehen. Ein einführender Überblick über Entwicklungen in diesem Zusammenhang soll die Hintergründe aktueller Probleme, die musikalisch aufgearbeitet werden, beleuchten. Im Anschluss daran erfolgt die einzelne Auseinandersetzung mit den ausgewählten Liedern, wofür die Texte zunächst im Original wiedergegeben und ins Deutsche übersetzt werden. Um eine tiefere Sicht in ihr musikalische Schaffen, ihre persönliche Ansichten und/oder etwaige Motivationen der KünstlerInnen zur Entstehung ihrer Lieder zu erhalten, wird ihr Werdegang beschrieben, bevor es zu einer ausführlichen Analyse über die inhaltlichen Dimensionen der Lieder kommt. Die darin aufgegriffenen Themen oder Ereignisse, die einer näheren Auseinandersetzung bedürfen, werden einzeln erörtert, um die gewonnenen Erkenntnisse in die anschließende Interpretation des entsprechenden Liedes einfließen zu lassen. In den Stücken, die hauptsächlich Phänomene im Kontext mit Gewalt, Armut und/oder der Minderheitenfrage ganz konkret auf Situationen in Istanbul beziehen, werden soziale Konflikte angesprochen, persönliche Schicksale mitgeteilt, einschneidende Großereignisse geschildert und politischer Unmut geäußert. Über inhaltliche Parallelen und Unterschiede in den besprochenen Liedern wird abschließend Bilanz gezogen