Context. Dark gamma-ray bursts (GRBs) constitute a significant fraction of the GRB population. In this paper, we present a multi-wavelength analysis (both prompt emission and afterglow) of an intense ...(3.98 × 10 −5 erg cm −2 using Fermi -Gamma-Ray Burst Monitor) two-episodic GRB 150309A observed early on until ∼114 days post burst. Despite the strong gamma-ray emission, no optical afterglow was detected for this burst. However, we discovered near-infrared (NIR) afterglow ( K S -band), ∼5.2 h post burst, with the CIRCE instrument mounted at the 10.4 m Gran Telescopio Canarias (hereafter, GTC). Aims. We aim to examine the characteristics of GRB 150309A as a dark burst and to constrain other properties using multi-wavelength observations. Methods. We used Fermi observations of GRB 150309A to understand the prompt emission mechanisms and jet composition. We performed early optical observations using the BOOTES robotic telescope and late-time afterglow observations using the GTC. A potential faint host galaxy was also detected in the optical wavelength using the GTC. We modelled the potential host galaxy of GRB 150309A in order to explore the environment of the burst. Results. The time-resolved spectral analysis of Fermi data indicates a hybrid jet composition consisting of a matter-dominated fireball and magnetic-dominated Poynting flux. The GTC observations of the afterglow revealed that the counterpart of GRB 150309A was very red, with H − K S > 2.1 mag (95% confidence). The red counterpart was not discovered in any bluer filters of Swift UVOT/BOOTES, which would be indicative of a high redshift origin. Therefore we discarded this possibility based on multiple arguments, such as spectral analysis of the X-ray afterglow constrain z < 4.15 and a moderate redshift value obtained using the spectral energy distribution (SED) modelling of the potential galaxy. The broadband (X-ray to NIR bands) afterglow SED implies a very dusty host galaxy with a deeply embedded GRB (suggesting A V ≳ 35 mag). Conclusions. The environment of GRB 150309A demands a high extinction towards the line of sight. Demanding dust obscuration is the most probable origin of optical darkness as well as the very red afterglow of GRB 150309A. This result establishes GRB 150309A as the most extinguished GRB known to date.
Dark GRBs constitute a significant fraction of the GRB population. In this paper, we present the multiwavelength analysis of an intense two-episodic GRB 150309A observed early on to ~114 days ...post-burst. Despite the strong gamma-ray emission, no optical afterglow was detected for this burst. However, we discovered near-infrared afterglow (\(K_{\rm S}\)-band), ~5.2 hours post burst, with the CIRCE instrument mounted at the 10.4m GTC. We used Fermi observations of GRB 150309A to understand the prompt emission mechanisms and jet composition. We performed the early optical observations using the BOOTES robotic telescope and late-time afterglow observations using the GTC. A potential faint host galaxy is also detected at optical wavelength using the GTC. We modelled the potential host galaxy of GRB 150309A in order to explore the environment of the burst. The time-resolved spectral analysis of Fermi data indicates a hybrid jet composition consisting of a matter-dominated fireball and magnetic-dominated Poynting flux. GTC observations of the afterglow revealed that the counterpart of GRB 150309A was very red, with H-\(K_{\rm S}\) > 2.1 mag (95 \(\%\) confidence). The red counterpart was not discovered in any bluer filters of Swift UVOT, indicative of high redshift origin. This possibility was discarded based on multiple arguments, such as spectral analysis of X-ray afterglow constrain z < 4.15 and a moderate redshift value obtained using spectral energy distribution modelling of the potential galaxy. The broadband afterglow SED implies a very dusty host galaxy with deeply embedded GRB (suggesting \(A_{\rm V}\) \(\gtrsim\) 35 mag). The environment of GRB 150309A demands a high extinction towards the line of sight, demanding dust obscuration is the most probable origin of optical darkness and the very red afterglow of GRB 150309A. This result makes GRB 150309A the highest extinguished GRB known to date.
Summary
Ash dieback, caused by the fungus Hymenoscyphus fraxineus, has been observed in Europe for several years. In Belgium, the disease was first reported in 2010. Besides crown defoliation and ...dieback, collar lesions have sometimes been reported. To evaluate the prevalence and the progression of collar lesions and crown defoliation in ash dieback‐affected stands of various ages, a survey was conducted in 2013 and 2014 on 268 ash trees (Fraxinus excelsior) originating from 17 Walloon forest stands. The results showed that the proportion of trees with collar lesions greatly increased between June 2013 and September 2014 and that there appeared to be no significant link between a tree's diameter‐at‐breast height (DBH) and collar lesion occurrence. The mean percentage of defoliation increased in each forest stand across time, with observations conducted in September 2013 and 2014 showing a positive correlation with the mean percentage of trees with collar lesions. Molecular tests were carried out on 103 additional trees originating from 12 of the 17 stands to evaluate the occurrence of H. fraxineus and Armillaria spp. at the collar level. Most of the trees (98%) were infected by H. fraxineus. In contrast, only 41% of the samples were infected with Armillaria spp., most commonly A. gallica and A. cepistipes. This study discusses the role of Armillaria spp. and the rapid increase in the number of trees with collar lesions within the context of the evolution of ash dieback in Europe.
In this study, 1700 primary school pupils (4th, 5th, and 6th grade) of 78 schools in Flanders and their headmasters were questioned about their use of the Internet and their perception and behaviour ...as to safe Internet use.
The results indicate that, next to the expected high level of Internet use at home, there is clear evidence of unsafe Internet use. Exploration of the data reveals that, of the currently taken specific interventions to promote safe Internet use and (un)safe Internet behaviour, only parent control seems to be significantly related to lower degrees of unsafe behaviour. No school-based interventions seem to be associated with the level of unsafe Internet use. The nature of current school-based interventions is discussed and considered to be less effective to expect an impact at the behavioural level. Next to implications for future research, recommendations to reorient school policies and action lines are presented.
Observations of binary stars containing an accreting black hole or neutron star often show x-ray emission extending to high energies (>10 kilo–electron volts), which is ascribed to an accretion disk ...corona of energetic particles akin to those seen in the solar corona. Despite their ubiquity, the physical conditions in accretion disk coronae remain poorly constrained. Using simultaneous infrared, optical, x-ray, and radio observations of the Galactic black hole system V404 Cygni, showing a rapid synchrotron cooling event in its 2015 outburst, we present a precise 461 ± 12 gauss magnetic field measurement in the corona. This measurement is substantially lower than previous estimates for such systems, providing constraints on physical models of accretion physics in black hole and neutron star binary systems.
Arrived in Germany: When Children Who have Fled Tell their Stories For this study, we listened to children who had fled with their families. We made a very conscious decision to focus on accompanied ...minors who have been displaced, because they go through the standard asylum system with their parent/guardian, which is why they often remain "invisible" as regards their own needs and their specific situation. We gave accompanied children who had fled a space where they could tell their stories and asked them to talk about their memories of their countries of origin, their experiences during their journey and on arrival in Germany, and their lives here, their concerns, but also their hopes and desires. The children presented here come from Afghanistan, Eritrea, Iran, Kosovo, Serbia and Syria. They therefore represent the countries from which people have set out on the always difficult, often life-threatening journey to Germany. And they represent the diversity of experiences of flight and arrival. Those responsible for this study come from various academic disciplines and areas of work. This was important to us in order to focus on the complexity of being a child and a child's everyday life under the conditions experienced while on the run. In view of the vulnerability of children, many challenges are regarded in a different light from previously, for example concerning the organisation of initial reception centres, education and care provisions, medical care, protected spaces and privacy. We want to encourage you to see these spaces, the bureaucratic procedures and coping with everyday life through the eyes of a child.
Child protection in Germany Gerarts, Katharina
Papers of Social Pedagogy,
7/2019, Letnik:
11, Številka:
1
Journal Article
The article looks at the history of childhood in the society, the country of Germany, and abroad. Today’s view of children as legal persons, recognizing their endowment with competencies and ...resources but also their ontological dependence, is a rather ‘new’ perspective in human history. Therefore the article first focuses onto the UN-Child-Right’s-Convention which was ratified in Germany in 1992. Second, a closer look at the development of the legal foundations of child protection in Germany shows how child protection in Germany was developed. The reader will get an overview about the child protection system in Germany, afterwards. The article ends with some recommendations to establish a child-rights-focused perspective in the child protection system in Germany.
Many companies and institutions have automated their business process in workflow management software. The novel programming paradigm Task-Oriented Programming (TOP) provides an abstraction for such ...software. The largest framework based on TOP, iTasks, has been used to develop real-world software. Workflow software often includes critical systems. In such cases it is important to reason over the software to ascertain its correctness. The lack of a formal iTasks semantics makes it unsuitable for formal reasoning. To this end TopHat has been developed as a TOP language with a formal semantics. However, TopHat lacks a graphical user interface (GUI), making it harder to develop practical TopHat systems. In this paper we present TopHat UI. By combining an existing server framework and user interface framework, we have developed a fully functioning proof of concept implementation in Haskell, on top of TopHat's semantics. We show that implementing a TOP framework is possible using a different host language than iTasks uses. None of TopHat's formal properties have been compromised, since the UI framework is completely separate from TopHat. We run several example programs and evaluate their generated GUI. Having such a system improves the quality and verifiability of TOP software in general.
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