The ν\nu-cleus experiment: A gram-scale fiducial-volume cryogenic detector for the first detection of coherent neutrino-nucleus scattering

We discuss a small-scale experiment, called $\nu$-cleus, for the first detection of coherent neutrino-nucleus scattering by probing nuclear-recoil energies down to the 10 eV-regime. The detector consists of low-threshold CaWO$_4$ and Al$_2$O$_3$ calorimeter arrays with a total mass of about 10 g and several cryogenic veto detectors operated at millikelvin temperatures. Realizing a fiducial volume and a multi-element target, the detector enables active discrimination of $\gamma$, neutron and surface backgrounds. A first prototype Al$_2$O$_3$ device, operated above ground in a setup without shielding, has achieved an energy threshold of ${\sim20}$ eV and further improvements are in reach. A sensitivity study for the detection of coherent neutrino scattering at nuclear power plants shows a unique discovery potential (5$\sigma$) within a measuring time of ${\lesssim2}$ weeks. Furthermore, a site at a thermal research reactor and the use of a radioactive neutrino source are investigated. With this technology, real-time monitoring of nuclear power plants is feasible.Comment: 14 pages, 19 figure

A Chandra Study of the Radio Galaxy NGC 326: Wings, Outburst History, and AGN Feedback

NGC 326 is one of the most prominent X- or Z-shaped radio galaxies (XRGs/ZRGs) and has been the subject of several studies attempting to explain its morphology through either fluid motions or reorientation of the jet axis. We examine a 100 ks archival Chandra exposure and find several features associated with the radio galaxy: a high-temperature front that may indicate a shock, high-temperature knots around the rim of the radio emission, and a cavity associated with the eastern wing of the radio galaxy. A reasonable interpretation of these features in light of the radio data allows us to reconstruct the history of the AGN outbursts. The active outburst was likely once a powerful radio source which has since decayed, and circumstantial evidence favors reorientation as the means to produce the wings. Because of the obvious interaction between the radio galaxy and the ICM and the wide separation between the active lobes and wings, we conclude that XRGs are excellent sources in which to study AGN feedback in galaxy groups by measuring the heating rates associated with both active and passive heating mechanisms.Comment: 13 pages, 8 figures, Accepted by Ap

CGCG 292-057 - a radio galaxy with merger-modulated radio activity

We announce the discovery of a unique combination of features in a radio source identified with the merger galaxy CGCG 292-057. The radio galaxy both exhibits a highly complex, X-like structure and shows signs of recurrent activity in the form of double-double morphology. The outer lobes of CGCG 292-057 are characterized by low radio power, P_{1400MHz} \simeq 2 * 10^{24} W\Hz^{-1}, placing this source below the FRII/FRI luminosity threshold, and are highly polarized (almost 20 per cent at 1400 MHz) as is typical of X-shaped radio sources. The host is a LINER-type galaxy with a relatively low black hole mass and double-peaked narrow emission lines. These features make this galaxy a primary target for studies of merger-triggered radio activity.Comment: 7 pages, 5 figures, submitted to MNRA

Creating prototypes for cooling urban water bodies

When addressing urban heat problems, climateconsciousurban design has been assumingthat urban water bodies such as canals, ditchesor ponds cool down their surroundings. Recentresearch shows that this is not necessarily thecase and that urban water bodies may actuallyhave a warming e!ect, particularly during latesummer season nights. There are howeverindications that water can have a coolingpotential if brought together with the rightshading, evaporation and ventilation strategies.Yet, it is not clear how this should be achieved.Knowledge on such spatial configurations shouldthus be developed and made available to designpractice. This challenge is directly addressed bythe “REALCOOL” project, a research aiming todefine design prototypes showing the physicalprocesses behind the e!ective cooling potentialof urban water bodies, that design professionalscan take as conceptual design frameworks

Nematoden als indicator voor de waterkwaliteit

Het beoordelen van de waterkwaliteit is een lastige zaak. Vaak wordt de chemische kwaliteit bepaald, maar eigenlijk willen we weten welke effecten die heeft op de biologische kwaliteit. Veld- en microscopisch onderzoek aan biologische indicatoren is bewerkelijk en bovendien zijn de resultaten niet eenduidig. Met de ontwikkeling van DNA-analysetechnieken is het mogelijk geworden nematoden in de waterbodem snel en accuraat te analyseren. Nematoden zijn kleine aaltjes (lengte 0,3 tot 1,0 mm) die in grote aantallen en met een aanzienlijke diversiteit in de waterbodem aanwezig zijn. De combinatie van hoge dichtheden en grote verscheidenheid maakt de nematodengemeenschap tot potentiële bio-indicator voor de waterkwaliteit. Een pilot liet zien dat DNA-analyse van nematoden in de waterbodem duidelijke signalen van eutrofiëring aangaf en daarmee inzicht gaf in de waterkwaliteit