We present the results of a two-year long optical monitoring program of the narrow-line Seyfert 1 galaxy Akn 564. The majority of this monitoring project was also covered by X-ray observations (RXTE) and for a period of ∼ 50 days, we observed the galaxy in UV (HST) and X-rays (RXTE & ASCA) simultaneously with the groundbased observations. Rapid and large-amplitude variations seen in the X-ray band, on a daily and hourly time-scale, were not detected at optical and UV wavelengths, which in turn exhibited much lower variability either on short (one day) or long (several months) time-scales. The only significant optical variations can be described as two 2-4 day events with ∼ 10% flux variations. We detect no significant optical line variations and thus cannot infer a reverberation size for the broad-line region. Similarly, the large X-ray variations seem to vanish when the light curve is smoothed over a period of 30 days. The UV continuum follows the X-rays with a lag of ∼ 0.4 days, and the optical band lags the UV band by ∼ 2 days. No significant correlation was found between the entire X-ray dataset and the optical band. Focusing on a 20-day interval around the strongest optical event we detect a significant X-ray-optical correlation with similar events seen in the UV and X-rays. Our data are consistent with reprocessing models on the grounds of the energy emitted in this single event. However, several large X-ray flares produced no corresponding optical emission.
The European Commission Horizon 2020 funded DEMOCRITOS project (2015-2017, see under democritos.esf.org) will be primary focused to prepare preliminary design of the ground, core and space demonstrators and their test benches for the megawatt class nuclear electric space propulsion INPPS flagship (International Nuclear Power and Propulsion System). In addition programmatic, organizational and funding aspects for international cooperation related to INPPS realization are sketched. The new project includes partners from Europe, Russia and the Brazilian guest observer IEAv and is the follow-up of the megawatt class nuclear electric propulsion European-Russian MEGAHIT project (www.megahit-eu.org). Europe already established the high power nuclear MEGAHIT and the low power nuclear (20 to 200 kW NEP) DiPoP (www.DiPoP.eu) roadmaps. Because Europe has started the implementations for INPPS flagship in the 2030-2040 timeframe, both roadmaps will be also described-from MEGAHIT the INPPS technology options, the launcher, assembly and system architecture, space mission requirements, communications and public support. In case of DiPoP it will be explained the survey of European capabilities, technical options, potential space missions and the public acceptance as well.
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