A hadronic scenario for HESS J1818-154

Aims: G15.4+0.1 is a faint supernova remnant (SNR) that has recently been associated with the gamma-ray source HESS J1818-154. We investigate a hadronic scenario for the production of the gamma-ray emission. Methods: Molecular 13CO (J=1-0) taken from the Galactic Ring Survey (GRS) and neutral hydrogen (HI) data from the Southern Galactic Plane Survey (SGPS) have been used in combination with new 1420 MHz radio continuum observations carried out with the Giant Metrewave Radio Telescope (GMRT). Results: From the new observations and analysis of archival data we provided for the first time a reliable estimate for the distance to the SNR G15.4+0.1 and discovered molecular clouds located at the same distance. On the basis of HI absorption features, we estimate the distance to G15.4+0.1 in 4.8+/-1.0 kpc. The 13CO observations clearly show a molecular cloud about 5 arcmin in size with two bright clumps, labeled A and B, clump A positionally associated with the location of HESS J1818-154 and clump B in coincidence with the brightest northern border of the radio SNR shell. The HI absorption and the 13CO emission study indicates a possible interaction between the molecular material and the remnant. We estimate the masses and densities of the molecular gas as (1.2+/-0.5)X10^3 M_sun and (1.5+/-0.4)X10^3 cm^-3 for clump A and (3.0+/-0.7)X10^3 M_sun and (1.1+/-0.3)X10^3 cm^-3 for clump B. Calculations show that the average density of the molecular clump A is sufficient to produce the detected gamma-ray flux, thus favoring a hadronic origin for the high-energy emission.Comment: Accepted to be published in Astronomy and Astrophysics Letter

A complete radio study of SNR G15.4+0.1 from new GMRT observations

The supernova remnant G15.4+0.1 is considered to be the possible counterpart of the gamma-ray source HESSJ1818-154. With the goal of getting a complete view of this remnant and understanding the nature of the gamma-ray flux, we conducted a detailed radio study that includes the search for pulsations and a model of the broadband emission for the G15.4+0.1/HESSJ1818-154 system. Low-frequency imaging at 624 MHz and pulsar observations at 624 and 1404 MHz towards G15.4+0.1 were carried out with the Giant Metrewave Radio Telescope (GMRT). We correlated the new radio data with observations of the source at X-ray and infrared wavelengths from XMM-Newton and Herschel observatories, respectively. To characterize the neutral hydrogen medium (HI) towards G15.4+0.1, we used data from the Southern Galactic Plane Survey. We modelled the spectral energy distribution using both hadronic and leptonic scenarios. From the combination of the new GMRT observations with existing data, we derived a continuum spectral index alpha=-0.62+-0.03 for the whole remnant. The local synchrotron spectra of G15.4+0.1, calculated from the combination of the GMRT data with 330 MHz observations from the VLA, tends to be flatter in the central part of the remnant, accompanying the region where the blast wave is impinging molecular gas. No spectral index trace was found indicating the radio counterpart to the pulsar wind nebula proposed from X-ray observations. In addition, the search for radio pulsations yielded negative results. Emission at far-infrared wavelengths is observed in the region where the SNR shock is interacting with dense molecular clumps. We also identified HI features forming a shell that wraps most of the outer border of G15.4+0.1. Characteristic parameters were estimated for the shocked HI gas. We found that either a purely hadronic or leptonic model is compatible with the broadband emission known so far.Comment: 11 pages, 9 figures, accepted for publication in Astronomy & Astrophysic

Risiken im Lebenszyklus: Theorie und Evidenz

Der einzelne Mensch ist im Lebensverlauf erheblichen biometrischen, ökonomischen, familiären und politischen Risiken ausgesetzt. Viele meinen, diese wären in den letzten Jahren größer geworden. Haben wir die richtigen Institutionen, um diese Risiken effizient abzudecken? Unter Institutionen verstehen wir individuelles Sparen, familiäre Hilfe, private Versicherungen und schließlich den Staat mit seinen Sozialversicherungen. Wo und wann funktionieren diese Institutionen? Wo und wann nicht? Was muss man tun, um sie zu verbessern? Wie sieht modernes "Social Risk Management" aus? Der erste Teil dieses Übersichtsbeitrags skizziert die wirtschaftstheoretischen Grundlagen des Sparverhaltens, der Portefeuillewahl und der Versicherungsnachfrage. Im Hauptteil werden die empirischen Befunde gesammelt, um im dritten Teil wirtschaftspolitische Schlussfolgerungen zu ziehen

An Empirical Evaluation of the Performance of Real-Time Illumination Approaches: Realistic Scenes in Augmented Reality

Augmented, Virtual, and Mixed Reality (AR/VR/MR) systems have been developed in general, with many of these applications having accomplished significant results, rendering a virtual object in the appropriate illumination model of the real environment is still under investigation. The entertainment industry has presented an astounding outcome in several media form, albeit the rendering process has mostly been done offline. The physical scene contains the illumination information which can be sampled and then used to render the virtual objects in real-time for realistic scene. In this paper, we evaluate the accuracy of our previous and current developed systems that provide real-time dynamic illumination for coherent interactive augmented reality based on the virtual object’s appearance in association with the real world and related criteria. The system achieves that through three simultaneous aspects. (1) The first is to estimate the incident light angle in the real environment using a live-feed 360∘ camera instrumented on an AR device. (2) The second is to simulate the reflected light using two routes: (a) global cube map construction and (b) local sampling. (3) The third is to define the shading properties for the virtual object to depict the correct lighting assets and suitable shadowing imitation. Finally, the performance efficiency is examined in both routes of the system to reduce the general cost. Also, The results are evaluated through shadow observation and user study

A Comparative Study on the Effects of Varying Concentrations of Eggshell Tea Fertilizer on Capsicum annum (Bell Pepper)

With the increasing worldwide demand for eggs, the continuous accumulation of these poses environmental threats because of their support for microbiological action. However, the fact that eggshells have high calcium content motivated researchers to explore their potential use as fertilizer for various plant species. Despite this, most studies only focused on applying eggshell fertilizers in solid form. Meanwhile, research on boosting bell pepper production remains sparse in the Philippines despite its increasing demand. This study examined the capabilities of eggshell tea, a liquid form of eggshell fertilizer, by determining which concentration would be most effective and least effective in growing bell peppers in the Philippines. The plants were categorized into four groups with different mass/volume percentage concentrations of eggshell tea applied: 0% (EF-0), 2% (EF-2), 4.5% (EF-4.5), and 7% (EF-7). The effects of each concentration on the number of leaves, leaf surface area, height, and growth rate of the plants were analyzed accordingly. Results showed that eggshell tea was most effective on EF-4.5 while least effective on EF-7. The EF-4.5 exhibited the fastest growth and was the healthiest regarding the tested parameters, while the controlled and EF-2 groups demonstrated moderate growth. The EF-7 exhibited the slowest growth, along with leaf yellowing, damage, and curls, attributed to over-fertilization. Eggshell tea was revealed to have a generally positive effect on bell peppers; however, too much concentration could cause damaging effects as plants that did not receive any fertilizer demonstrated better results than EF-7

"Better Safe than Sorry" - Individual Risk-free Pension Schemes in the European Union - Macroeconomic Benefits, the Mobile Working Citizen's Perspective and Why Nots

Variations between the diverse pension systems in the member states of the European Union hamper labour market mobility, across country borders but also within the countries of the European Union. From a macroeconomic perspective, and in the light of demographic pressure, this paper argues that allowing individual instead of collective pension building would greatly improve labour market flexibility and thus enhance the functioning of the monetary union. I argue that working citizens would benefit, for three reasons, from pension saving in a risk-free savings account. First, citizens would have a clear picture of the accumulation of their own pension savings throughout their working life. Second, they would pay hardly any extra costs and, third, once retired they would not be subject to the whims of government or other pension fund managers. This paper investigates the feasibility of individual pension building under various parameter settings by calculating the pension saved during a working life and the pension dis-saved after retirement. The findings show that there are no reasons why the European Union and individual member states should not allow individual risk-free pension savings accounts. This would have macroeconomic benefits and provide a solid pension provision that can enhance mobility, instead of engaging workers in different mandatory collective pension schemes that exist around in the European Union

Socioeconomic inequalities in the quality of life of older Europeans in different welfare regimes

Background: Whether socioeconomic inequalities in health and well-being persist into old age and are narrower in more generous welfare states is debated. We investigated the magnitude of socioeconomic inequality in the quality of life of Europeans in early old age and the influence of the welfare regime type on these relationships.<p></p> Methods: Data from individuals aged 50–75 years (n = 16 074) residing in 13 European countries were derived from Waves 2 and 3 of the Survey of Health, Ageing and Retirement in Europe. Slope indices of inequality (SIIs) were calculated for the association between socioeconomic position and CASP-12, a measure of positive quality of life. Multilevel linear regression was used to assess the overall relationship between socioeconomic position and quality of life, using interaction terms to investigate the influence of the type of welfare regime (Southern, Scandinavian, Post-communist or Bismarckian).<p></p> Results: Socioeconomic inequalities in quality of life were narrowest in the Scandinavian and Bismarckian regimes, and were largest by measures of current wealth. Compared with the Scandinavian welfare regime, where narrow inequalities in quality of life by education level were found in both men (SII = 0.02, 95% CI: −1.09 to 1.13) and women (SII = 1.11, 95% CI: 0.05–2.17), the difference in quality of life between the least and most educated was particularly wide in Southern and Post-communist regimes.<p></p> Conclusion: Individuals in more generous welfare regimes experienced higher levels of quality of life, as well as narrower socioeconomic inequalities in quality of life.<p></p&gt