SALSA: a tool to estimate the stray light contamination for low-Earth orbit observatories

Stray light contamination reduces considerably the precision of photometric of faint stars for low altitude spaceborne observatories. When measuring faint objects, the necessity of coping with stray light contamination arises in order to avoid systematic impacts on low signal-to-noise images. Stray light contamination can be represented by a flat offset in CCD data. Mitigation techniques begin by a comprehensive study during the design phase, followed by the use of target pointing optimisation and post-processing methods. We present a code that aims at simulating the stray-light contamination in low-Earth orbit coming from reflexion of solar light by the Earth. StrAy Light SimulAtor (SALSA) is a tool intended to be used at an early stage as a tool to evaluate the effective visible region in the sky and, therefore to optimise the observation sequence. SALSA can compute Earth stray light contamination for significant periods of time allowing missionwide parameters to be optimised (e.g. impose constraints on the point source transmission function (PST) and/or on the altitude of the satellite). It can also be used to study the behaviour of the stray light at different seasons or latitudes. Given the position of the satellite with respect to the Earth and the Sun, SALSA computes the stray light at the entrance of the telescope following a geometrical technique. After characterising the illuminated region of the Earth, the portion of illuminated Earth that affects the satellite is calculated. Then, the flux of reflected solar photons is evaluated at the entrance of the telescope. Using the PST of the instrument, the final stray light contamination at the detector is calculated. The analysis tools include time series analysis of the contamination, evaluation of the sky coverage and an objects visibility predictor. Effects of the South Atlantic Anomaly and of any shutdown periods of the instrument can be added. Several designs or mission concepts can be easily tested and compared. The code is not thought as a stand-alone mission designer. Its mandatory inputs are a time series describing the trajectory of the satellite and the characteristics of the instrument. This software suite has been applied to the design and analysis of CHEOPS (CHaracterizing ExOPlanet Satellite). This mission requires very high precision photometry to detect very shallow transits of exoplanets. Different altitudes and characteristics of the detector have been studied in order to find the best parameters, that reduce the effect of contamination. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

itw : im dialog - Forschungen zum Gegenwartstheater

Die Reihe itw : im dialog – Forschungen zum Gegenwartstheater widmet sich den Ästhetiken, Themen und Tendenzen gegenwärtigen Theaterschaffens und will Impulse zu seiner Erforschung geben. Ausgehend von der besonderen Position des Gegenwartstheaters als Ort der unmittelbaren Konfrontation mit gesellschaftlichen und politischen Fragen, wird dieses zum Gegenstand wissenschaftlicher Problematisierung und Reflexion. Die neugegründete Reihe gibt den teils von Inszenierungsanalysen ausgehenden theatertheoretischen sowie theaterhistorischen Reflexionen und den Gesprächen mit Künstlerinnen und Künstlern ein erweitertes wissenschaftliches Forum. Die Bände der Reihe werden zeitnah zu den »itw : im dialog«-Veranstaltungen produziert. So können die aus dem internationalen Austausch mit den Theaterforschenden und Theaterschaffenden gewonnenen Erkenntnisse und Anregungen umgehend in den akademischen Diskurs zum Gegenwartstheater einfließen.

Gastroesophageal intussusception in a leopard (Panthera pardus).

An 8-yr-old male leopard (Panthera pardus) was presented with a 4-day history of lethargy, vomiting, and anorexia. Thoracic and abdominal radiographs revealed a soft-tissue mass cranial to the diaphragm and atypical appearance of the gastric fundus. Esophagoscopy revealed gastric mucosa in the lumen of the esophagus, which confirmed gastroesophageal intussusception. An exploratory celiotomy with manual reduction of the intussusception was performed. Reduction was verified by intraoperative esophagoscopy and gastroscopy. An incisional fundic gastropexy to the left abdominal wall was performed to reduce the chance of a recurrence of the intussusception. No postoperative complications related to the surgery were observed, and the animal resumed eating within 48 hr of surgery. A subsequent recurrence of clinical signs was not noted by the owner.

Esophageal hiatal hernia in three exotic felines--Lynx lynx, Puma concolore, Panthera leo.

Hiatal hernia was diagnosed in three exotic felines-lynx (Lynx lynx), cougar (Puma concolore), and lion (Panthera leo). All cats had a history of anorexia. Thoracic and abdominal radiographs showed evidence of a soft tissue mass within the caudal mediastinum suggestive of a hiatal hernia in all animals. A barium esophagram was performed in one case. All animals underwent thoracic or abdominal surgery for hernia reduction. Surgical procedures included: intercostal thoracotomy with herniorrhaphy and esophagopexy (lynx and cougar), and incisional gastropexy (lion). Concurrent surgical procedures performed were gastrotomy for gastric foreign body removal and jejunostomy tube placement. Clinical signs related to the hiatal hernia disappeared after surgery and recurrence of signs was not reported for the time of follow-up.

Sozialisation und Emanzipation in der Theologie und Seelsorge

Religion steht in der Spannung zwischen einerseits dem durch die Religionskritik Freuds genährten Vorwurf der Einengung und des Konservativismus und andrerseits der ihr ureigenen Erfahrung der Befreiung, die im Exodus-Erlebnis des Alten Testaments angelegt ist. Diese Ambivalenz von Religion macht sie zu einer steten Herausforderung und bedarf der fortwährenden Reflexion. Die Aufgabe von Seelsorge ist es, das befreiende und lebensfreundliche Potential von Religion hervorzuheben und zu stärken sowie Vertrauen ins eigene Geliebt- und Gewolltsein zu schaffen, denn dieses ist die Grundvoraussetzung aller möglichen Emanzipation.