@inproceedings{Sonneborn2007, author = {Sonneborn, G.}, title = {Imaging and spectroscopy with the James Webb Space Telescope}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17983}, year = {2007}, abstract = {The James Webb Space Telescope (JWST) is a large, infrared-optimized space telescope scheduled for launch in 2013. JWST will find the first stars and galaxies that formed in the early universe, connecting the Big Bang to our own Milky Way galaxy. JWST will peer through dusty clouds to see stars forming planetary systems, connecting the MilkyWay to our own Solar System. JWST's instruments are designed to work primarily in the infrared range of 1 - 28 μm, with some capability in the visible range. JWST will have a large mirror, 6.5 m in diameter, and will be diffraction-limited at 2 μm (0.1 arcsec resolution). JWST will be placed in an L2 orbit about 1.5 million km from the Earth. The instruments will provide imaging, coronography, and multi-object and integral-field spectroscopy across the 1 - 28 μm wavelength range. The breakthrough capabilities of JWST will enable new studies of massive star winds from the Milky Way to the early universe.}, language = {en} } @inproceedings{Owocki2007, author = {Owocki, S. P.}, title = {Dynamical simulation of the "velocity-porosity" reduction in observed strength of stellar wind lines}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17992}, year = {2007}, abstract = {I use dynamical simulations of the line-driven instability to examine the potential role of the resulting flow structure in reducing the observed strength of wind absorption lines. Instead of the porosity length formalism used to model effects on continuum absorption, I suggest reductions in line strength can be better characterized in terms of a velocity clumping factor that is insensitive to spatial scales. Examples of dynamic spectra computed directly from instability simulations do exhibit a net reduction in absorption, but only at a modest 10-20\% level that is well short of the ca. factor 10 required by recent analyses of PV lines.}, language = {en} } @inproceedings{Blomme2007, author = {Blomme, R.}, title = {Corotating Interaction Regions and clumping}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18100}, year = {2007}, abstract = {We present hydrodynamical models for Corotating Interaction Regions, which were used by Lobel (2007) to model the Discrete Absorption Components in HD 64760. We also discuss our failure to model the rotational modulations seen in the same star.}, language = {en} } @inproceedings{Kholtygin2007, author = {Kholtygin, A. F.}, title = {Wavelets for looking for clumping in the wind of OB stars}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17796}, year = {2007}, abstract = {Clumping in hot-star winds : proceedings of an international workshop held in Potsdam, Germany, 18. - 22. June 2007}, language = {en} } @inproceedings{UrbanejaKudritzkiPuls2007, author = {Urbaneja, M. A. and Kudritzki, R.-P. and Puls, Joachim}, title = {Clumping in the winds of O-type CSPNs}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17801}, year = {2007}, abstract = {Recent studies of massive O-type stars present clear evidences of inhomogeneous and clumped winds. O-type (H-rich) central stars of planetary nebulae (CSPNs) are in some ways the low mass-low luminosity analogous of those massive stars. In this contribution, we present preliminary results of our on-going multi-wavelength (FUV, UV and optical) study of the winds of Galactic CSPNs. Particular emphasis will be given to the clumping factors derived by means of optical lines (Hα and Heii 4686) and "classic" FUV (and UV) lines.}, language = {en} } @inproceedings{deKoterVinkMuijres2007, author = {de Koter, A. and Vink, J. S. and Muijres, L.}, title = {Constraints on wind clumping from the empirical mass-loss vs. metallicity relation for early-type stars}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17736}, year = {2007}, abstract = {We present the latest results on the observational dependence of the mass-loss rate in stellar winds of O and early-B stars on the metal content of their atmospheres, and compare these with predictions. Absolute empirical rates for the mass loss of stars brighter than 10\$^{5.2} L_{\odot}\$, based on H\$\alpha\$ and ultraviolet (UV) wind lines, are found to be about a factor of two higher than predictions. If this difference is attributed to inhomogeneities in the wind this would imply that luminous O and early-B stars have clumping factors in their H\$\alpha\$ and UV line forming regime of about a factor of 3--5. The investigated stars cover a metallicity range \$Z\$ from 0.2 to 1 \$Z_{\odot}\$. We find a hint towards smaller clumping factors for lower \$Z\$. The derived clumping factors, however, presuppose that clumping does not impact the predictions of the mass-loss rate. We discuss this assumption and explain how we intend to investigate its validity in more detail.}, language = {en} } @inproceedings{ReyesIturbideVelazquezRosado2007, author = {Reyes-Iturbide, J. and Vel{\´a}zquez, P. and Rosado, M.}, title = {3D numerical model for an asymmetrical superbubble}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17724}, year = {2007}, abstract = {Massive stars usually form groups such as OB associations. Their fast stellar winds sweep up collectively the surrounding insterstellar medium (ISM) to generate superbubbles. Observations suggest that superbubble evolution on the surrounding ISM can be very irregular. Numerical simulations considering these conditions could help to understand the evolution of these superbubbles and to clarify the dynamics of these objects as well as the difference between observed X-ray luminosities and the predicted ones by the standard model (Weaver et al. 1977).}, language = {en} } @inproceedings{GrohHillierDamineli2007, author = {Groh, J. H. and Hillier, D. J. and Damineli, A.}, title = {Mass-loss rate and clumping in LBV stars : the impact of time-dependent effects}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17773}, year = {2007}, abstract = {This paper outlines a newly-developed method to include the effects of time variability in the radiative transfer code CMFGEN. It is shown that the flow timescale is often large compared to the variability timescale of LBVs. Thus, time-dependent effects significantly change the velocity law and density structure of the wind, affecting the derivation of the mass-loss rate, volume filling factor, wind terminal velocity, and luminosity. The results of this work are directly applicable to all active LBVs in the Galaxy and in the LMC, such as AG Car, HR Car, S Dor and R 127, and could result in a revision of stellar and wind parameters. The massloss rate evolution of AG Car during the last 20 years is presented, highlighting the need for time-dependent models to correctly interpret the evolution of LBVs.}, language = {en} } @misc{HowaldElsenbeerLaczkoetal.1995, author = {Howald, Markus and Elsenbeer, Helmut and Laczko, Endre and Schlunegger, Urs Peter}, title = {Capillary electrophoresis as a fast and universal tool in soil analysis}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16913}, year = {1995}, abstract = {Fast analysis of different species of molecules in soils is investigated by capillary electrophoresis (CE). Several CE techniques for the analysis of inorganic ions and carbohydrates have been tested. With regard to the intents of pedologists and the usually large number of soil analyses a bundle of CE systems is proposed, capable of effecting time-saving soil analyses. Adapted electrolyte systems recently published and new separation systems are described. Examples of the application of these methods to two different soil samples are presented.}, language = {en} } @article{Kitagawa2007, author = {Kitagawa, Yoshihisa}, title = {When we fail to question in Japanese}, series = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, volume = {9}, journal = {Interdisciplinary studies on information structure : ISIS ; working papers of the SFB 632}, editor = {Ishihara, Shinichiro and Petrova, Svetlana and Schwarz, Anne}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1866-4725}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-24481}, pages = {29 -- 64}, year = {2007}, abstract = {When we pay close attention to the prosody of Wh-questions in Japanese, we discover many novel and interesting empirical puzzles that would require us to devise a much finer syntactic component of grammar. This paper addresses the issues that pose some problems to such an elaborated grammar, and offers solutions, making an appeal to the information structure and sentence processing involved in the interpretation of interrogative and focus constructions.}, language = {en} }