The spectra of three newly discovered high-redshift quasars

Spectra of three high-redshift quasars discovered on low-dispersion objective prism plates were obtained. We present the emission line identifications and redshifts of the objects. Equivalent widths, line widths and low-resolution line profiles are given characterizing the quasar emission region. The Lyα and CIV equivalent widths indicate that the considered quasars are luminous objects at high redshift. Both these equivalent widths are too low by a factor 4, whereas the N V/Lyα ratio is 5 times larger than predicted by the photoionisation models. The line profiles are compared with logarithmic, electron-scattering and Gaussian profiles. In all the spectra rich absorption line systems are evident.     

Short-Term Effects of an Oil Spill on Marsh-Edge Fishes and Decapod Crustaceans

On 19 April 2005, an oil spill occurred in southeastern Louisiana’s Barataria Bay estuary. We used a drop sampler to characterize the marsh-edge nekton community. Thirty-six locations were sampled in pre- and post-spill time frames from March through May 2005. Before–after control–impact (BACI) analyses of the total number of individuals (fishes + decapod crustaceans), total fishes, and sensitive species found significant interactions between the temporal (before/after) and spatial (control/impact) treatments and indicated an effect of the oil spill. Nonparametric analyses detected varied faunal assemblages across temporal treatments, but were similar in species composition among spatial treatments. While the BACI analyses showed event effects, differences were not strongly detected in nonparametric analyses of community structure. Fish are mobile and left the spill area after the disturbance, whereas the less mobile but more numerous benthic decapod crustaceans remained. The overall community structure appears to be robust and quickly recovered from the localized spill event.     

Plate and intraplate processes of Hercynian Europe during the late paleozoic

It is speculated that until Late Carboniferous time the region of Hercynian Europe was occupied by an elongated island arc system underlain by a segment of continental crust. In the Upper Carboniferous, two subduction zones are assumed to have extended from the north and south beneath Hercynian Europe. An extensive zone of hot, partially molten upper mantle lay above and between these, and diapiric uprise of portions of this material led to separation of mafic magmas, widespread partial melting in the lower and middle crust, high temperature-low pressure metamorphism in crustal rocks, and regional uplift and extension of the crust, as indicated by intermontane troughs and their associated volcanic rocks.In Visean to Westphalian time Hercynian Europe collided with both the large neighbouring plates North America-Europe and Africa. During these diachronous collisions and owing to reduced rigidity of the relatively hot island arc crust, the irregular continental margins of the larger and thicker continental plates induced oroclinal bending of Hercynian Europe. After the collision processes had been terminated, processes of upper mantle activity continued, causing further crustal uplift and even, enhanced crustal extension for several tens of million years into the Lower Permian. Decline of the upper mantle activity beneath Hercynian Europe is indicated by crustal subsidence and formation of a peneplain in Permian time followed by the Upper Permian transgression of both the Zechstein sea and the Tethys sea which mark the end of the Hercynian geodynamic cycle.     

On the volcanology of the Gibeon Kimberlite Field, Namibia

Kimberlite volcanism in the Upper Cretaceous Gibeon Kimberlite Field, southern Namibia, consisting of at least 42 diatremes and a number of associated dykes, is closely related to carbonatitic and ultrabasic volcanic and intrusive activity which occurred at the margin of the Field. The volcanology of the diatremes and dykes as well as their structural setting is reported here. Because of the paleohydrogeological setting, and since juvenile kimberlite occurring in dykes, intrusive plugs, and spherical lapilli is devoid of vesicles, a phreatomagmatic eruption mechanism is proposed for the genesis of the kimberlite diatremes. Karoo dolerite, basalt and sediment xenoliths in the diatremes provide evidence for the former extent of Karoo strata at the time of eruption.     

Die Intensitätsverteilung der Himmelsstrahlung während der totalen Sonnenfinsternis Am 15. 2. 1961 auf Grund photographischer Messungen

Zusammenfassung Es wird über eine photographische Methode berichtet, die gestattet, die Verteilung der Himmelsstrahlung zu bestimmen. Der Himmel wird mit einer Weitwinkelkamera photographiert und die Aufnahmen werden mit einem Photometer ausgewertet. Über einen Graukeil, der auf das gleiche filmmaterial aufbelichtet und mit den Aufnahmen zusammen entwickelt wird, lassen sich die mit dem Photometer ermittelten Schwärzungswerte in (relative) Intensitätswerte der Himmelsstrahlung umrechnen. Der durch das Photoobjektiv bedingte Helligkeitsabfall von der Bildmitte aus nach den Bildrändern zu wird experimentell ermittelt und als Korrektur an den Meßwerten angebracht. Die Intensitätsverteilung der Himmelsstrahlung während der totalen Sonnenfinsternis am 15. Februar 1961 in Viareggio (Norditalien), am Abend zuvor und am Folgetag wird wiedergegeben und diskutiert. Während der totalen Verfinsterung spiegelt sich insbesondere die Wanderung des Mondschattens relativ zum Beobachtungsort in den Darstellungen wieder. Während der partiellen Verfinsterung ist dagegen die relative Helligkeitsverteilung praktisch die gleiche wie bei unverfinsterter Sonne.

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Summary A photographic method is described which permits to determinate the distribution of the sky radiation. The sky is photographed by a wide angle camera and the resulting pictures are evaluated by a photometer. A photometric step wedge copied on a film of the same type and number is developed together with the pictures. Then the density values measured by the photometer can be transformed into (relative) intensity values of the sky radiation. The decrease in brightness from the centre of the picture to the rim caused by the photographic lens is determined experimentally and is taken into account as a correction to the density values. The distribution of intensity of the sky radiation in Viareggio (North Italy) during the total eclipse of the sun on the 15th of february 1961, on the previous evening and on the following day are shown and discussed. During the total eclipse especially the migration of the moon's shadow in relation to the observation point is clearly defined. During the partial eclipse, however, practically the same relative distribution of sky radiation is found as without eclipse.

     

Separation of gamma and hadron initiated air showers with energies between 20 and 500 TeV

The discrimination between air showers initiated by γ rays and by hadrons is one of the fundamental problems in experimental cosmic-ray physics. The physics of this ‘γ/hadron separation’ is discussed in this paper. We restrict ourselves to the energy range from about 20 to 500 TeV, and take only the information contained in the lateral Čerenkov light distribution and the number of electrons at the detector level into consideration. An understanding of the differences between air showers generated by γ rays and those due to hadrons leads us to formulate suitable observables for the separation process. Angle integrating Čerenkov arrays (AICA) offer a promising new approach to ground-based γ-ray astronomy in the energy region from about 20 to 500 TeV. In order to establish this technique, an efficient suppression of the overwhelming hadronic background radiation is required. As an example for our general discussion, we present one method for γ/hadron separation in AICAs called ‘LES’. It is based on the simultaneous determination of the shower size and some characteristic parameters of the lateral distribution of the Čerenkov light. The potential inherent within this technique is demonstrated in quantitative detail for the existing ‘AIROBICC’ AICA. We also propose an objective measure of the intrinsic sensitivity of a detection scheme in ground-based γ-ray astronomy, the ‘reduced quality factor’. It is shown that AICAs may reach a sensitivity to γ-ray point sources in the high VHE range similar to that of the Čerenkov-telescope imaging technique in the low VHE region.     

Ultra-Deep Optical Spectroscopy with PMAS. Using the Nod-and-Shuffle Technique

PMAS, the Potsdam Multi-Aperture Spectrophotometer, is a new integral field spectrograph in the optical, which is optimized for good transmission and high image quality from 350 nm to 1 μm. We present our plan to implement a CCD charge-shuffle mode to allow for beam switching with a very high degree of sky subtraction accuracy for faint object 3-D spectroscopy. This revised version was published online in July 2006 with corrections to the Cover Date.     

The quasar population density as a result of the formation rate and the evolutionary pathes II. Adaption to the observation

The continuity equation of CAVALIERE et al. (1971) generalized to age-dependent luminosity evolution (BOLLER and LIEBSCHER 1989) is used to calculate quasar luminosity functions. For some combinations of source functions S(L, t) and evolutionary pathes M(L) we discuss the resulting N — m relations and the amount of the X-ray background and compare them with actual results of observation. We can exclude certain models, (S(L, t), M(L)). We cannot yet decide what the actual source function and the actual evolutionary path are.     

Tidal inundation mapping under enhanced land subsidence in Semarang,Central Java Indonesia

Tidal inundation by high tide under enhanced land subsidence is a damaging phenomenon and a major threat to the Semarang urban area in Indonesia. It impacts on economic activities, as well as the cost of an emergency program and causes interruption of pubic services, danger of infectious diseases and injury to human lives. This study examines a spatial analysis tool on the GIS-raster system for the tidal inundation mapping based on the subsidence-benchmark data and modified detail digital elevation model. Neighborhood operation and iteration model as a spatial analysis tool have been applied in order to calculate the encroachment of the tidal inundation on the coastal area. The resulting map shows that the tidal flood spreads to the lowland area and causes the inundation of coastal settlement, infrastructure, as well as productive agricultural land, i.e., the fish-pond area. The monitoring of the vulnerable area due to the tidal inundation under the scenario of extended land subsidence plays an important role in long-term coastal zone management in Semarang.