Design and performance of the prototype Schwarzschild-Couder telescope camera

International audienceThe prototype Schwarzschild-Couder Telescope (pSCT) is a candidate for a medium-sized telescope in the Cherenkov Telescope Array. The pSCT is based on a dual-mirror optics design that reduces the plate scale and allows for the use of silicon photomultipliers as photodetectors. The prototype pSCT camera currently has only the central sector instrumented with 25 camera modules (1600 pixels), providing a 2.68-deg field of view (FoV). The camera electronics are based on custom TARGET (TeV array readout with GSa/s sampling and event trigger) application-specific integrated circuits. Field programmable gate arrays sample incoming signals at a gigasample per second. A single backplane provides camera-wide triggers. An upgrade of the pSCT camera that will fully populate the focal plane is in progress. This will increase the number of pixels to 11,328, the number of backplanes to 9, and the FoV to 8.04 deg. Here, we give a detailed description of the pSCT camera, including the basic concept, mechanical design, detectors, electronics, current status, and first light

Anti-brood parasite defences : the role of individual and social learning

In this chapter, we consider the ways in which learning is involved in the antibrood parasitism defences that hosts deploy across the nesting cycle. Brood parasitism varies in space and through time, and hosts have accordingly evolved plastic defences that can be tuned to local conditions. Hosts can achieve their defence plasticity by individual and social learning, as well as by experienceindependent mechanisms. While these mechanisms can profoundly affect the coevolutionary dynamics between hosts and their brood parasites, our understanding of how they feature across the host nesting cycle is far from complete. Hosts can actively defend themselves against brood parasitism via a variety of behaviours, including nest defence, egg discrimination and chick discrimination. Such anti-brood parasite defences rely on the host ’ s ability to recognise and then defend against the parasitic threat, and there is good evidence that both these components of discrimination can be in fl uenced by learning. To date, most research has focused on the function of learning in nest defence, but the learning mechanisms underlying egg discrimination are much better understood; and despite some notable exceptions, the role of learning in chick discrimination remains largely unexplored. An important challenge now is to understand the observed plasticity of anti-brood parasite defences in the context of environmental heterogeneity and speci fi cally in terms of variation in the presence, detection and reliability of parasitism cues

Anti-brood Parasite Defences: The Role of Individual and Social Learning

In this chapter, we consider the ways in which learning is involved in the antibrood parasitism defences that hosts deploy across the nesting cycle. Brood parasitism varies in space and through time, and hosts have accordingly evolved plastic defences that can be tuned to local conditions. Hosts can achieve their defence plasticity by individual and social learning, as well as by experienceindependent mechanisms. While these mechanisms can profoundly affect the coevolutionary dynamics between hosts and their brood parasites, our understanding of how they feature across the host nesting cycle is far from complete. Hosts can actively defend themselves against brood parasitism via a variety of behaviours, including nest defence, egg discrimination and chick discrimination. Such anti-brood parasite defences rely on the host’s ability to recognise and then defend against the parasitic threat, and there is good evidence that both these components of discrimination can be influenced by learning. To date, most research has focused on the function of learning in nest defence, but the learning mechanisms underlying egg discrimination are much better understood; and despite some notable exceptions, the role of learning in chick discrimination remains largely unexplored. An important challenge now is to understand the observed plasticity of anti-brood parasite defences in the context of environmental heterogeneity and specifically in terms of variation in the presence, detection and reliability of parasitism cues