LOFAR 144-MHz follow-up observations of GW170817

ABSTRACT We present low-radio-frequency follow-up observations of AT 2017gfo, the electromagnetic counterpart of GW170817, which was the first binary neutron star merger to be detected by Advanced LIGO–Virgo. These data, with a central frequency of 144 MHz, were obtained with LOFAR, the Low-Frequency Array. The maximum elevation of the target is just 13${_{.}^{\circ}}$7 when observed with LOFAR, making our observations particularly challenging to calibrate and significantly limiting the achievable sensitivity. On time-scales of 130–138 and 371–374 d after the merger event, we obtain 3σ upper limits for the afterglow component of 6.6 and 19.5 mJy beam−1, respectively. Using our best upper limit and previously published, contemporaneous higher frequency radio data, we place a limit on any potential steepening of the radio spectrum between 610 and 144 MHz: the two-point spectral index $\alpha ^{610}_{144} \gtrsim$ −2.5. We also show that LOFAR can detect the afterglows of future binary neutron star merger events occurring at more favourable elevations.</jats:p

Guilds in the transition to modernity: the cases of Germany, United Kingdom, and the Netherlands

One important aspect of the transition to modernity is the survival of elements of the Old Regime beyond the French Revolution. It has been claimed that this can explain why in the late 19th and early 20th centuries some Western countries adopted national corporatist structures while others transformed into liberal market economies. One of those elements is the persistence or absence of guild traditions. This is usually analyzed in a national context. This paper aims to contribute to the debate by investigating the development of separate trades in Germany, the United Kingdom and the Netherlands throughout the 19th century. We distinguish six scenarios of what might have happened to crafts and investigate how the prevalence of each of these scenarios in the three countries impacted on the emerging national political economies. By focusing on trades, rather than on the national political economy, our analysis demonstrates that in each country the formation of national political economies and citizenship rights was not the result of a national pattern of guild survival. Rather, the pattern that emerged by the end of the 19th century was determined by the balance between old and new industries, and between national and regional or local government

Picturing Generosity. Factors of success and failure of national campaigns in the Netherlands

In this study, we investigate the success of national campaigns for charitable causes in the Netherlands using historical data from archival sources, including newspapers, and the internet. We describe the 102 national campaigns held in the Netherlands between 1951 and 2011, focusing on uniquely Dutch contextual features such as a society organized along vertical pillars and highly formalized collaboration between international aid organizations. We then formulate and test hypotheses concerning possible explanations for the success of national campaigns as a specific type of fundraising campaign. We focus on the effect of campaigns organized for “innocent” victims, versus campaigns organized for victims of man-made disasters, the effect of media coverage on campaigns, campaign frequency, government contributions, and economic conditions. The results show that campaigns for victims of man-made disasters are less successful. Campaigns organized in periods of fewer competing campaigns and campaigns receiving government support are more successful. </jats:p

Linked Death—Representing, Publishing, and Using Second World War Death Records as Linked Open Data

War history of the Second World War (WW2), humankind’s largest disaster, is of great interest to both laymen and researchers. Most of us have ancestors and relatives who participated in the war, and in the worst case got killed. Researchers are eager to find out what actually happened then, and even more importantly why, so that future wars could perhaps be prevented. The darkest data of war history are casualty records—from such data we could perhaps learn most about the war. This paper presents a model and system for representing death records as linked data, so that (1) citizens could find out more easily what happened to their relatives during WW2 and (2) digital humanities (DH) researchers could (re)use the data easily for research.Peer reviewe