@article{PietschBarberkaGeueetal.1997, author = {Pietsch, Ullrich and Barberka, Thomas Andreas and Geue, Thomas and St{\"o}mmer, Ralph}, title = {X-ray scattering from thin organic films and multilayers}, year = {1997}, language = {en} } @article{StoemmerGoebelHubetal.1998, author = {St{\"o}mmer, Ralph and G{\"o}bel, H. and Hub, W. and Pietsch, Ullrich}, title = {X-ray scattering from silicon surfaces}, year = {1998}, language = {en} } @article{PietschTsirelsonGorfan2003, author = {Pietsch, Ullrich and Tsirelson, Vladimir G. and Gorfan, S. V.}, title = {X-ray scattering amplitude of an atom in a permanent external electric field}, year = {2003}, language = {en} } @article{PietschKubowiczThuenemannetal.2003, author = {Pietsch, Ullrich and Kubowicz, Stephan and Th{\"u}nemann, Andreas F. and Geue, Thomas and Watson, M. D. and Tchebotareva, N. and M{\"u}llen, K.}, title = {X-ray reflectivity study of an amphiphilic hex-peri-hexabenzocoronene at a structured silicon wafer surface}, year = {2003}, language = {en} } @article{GeueHennebergPietsch2002, author = {Geue, Thomas and Henneberg, Oliver and Pietsch, Ullrich}, title = {X-ray reflectivity from sinusoidal surface relief gratings}, issn = {0023-4753}, year = {2002}, language = {en} } @article{Pietsch2002, author = {Pietsch, Ullrich}, title = {X-ray reflectivity from sinusoidal surface relief gratings}, year = {2002}, language = {en} } @article{PoloucekPietschGeueetal.2001, author = {Poloucek, P. and Pietsch, Ullrich and Geue, Thomas and Symietz, Christian and Brezesinski, Gerald}, title = {X-ray reflectivity analysis of thin complex Langmuir-Blodgett films}, year = {2001}, language = {en} } @article{GiewekemeyerKruegerKalbfleischetal.2011, author = {Giewekemeyer, K. and Krueger, S. P. and Kalbfleisch, S. and Bartels, Meike and Beta, Carsten and Salditt, T.}, title = {X-ray propagation microscopy of biological cells using waveguides as a quasipoint source}, series = {Physical review : A, Atomic, molecular, and optical physics}, volume = {83}, journal = {Physical review : A, Atomic, molecular, and optical physics}, number = {2}, publisher = {American Physical Society}, address = {College Park}, issn = {1050-2947}, doi = {10.1103/PhysRevA.83.023804}, pages = {7}, year = {2011}, abstract = {We have used x-ray waveguides as highly confining optical elements for nanoscale imaging of unstained biological cells using the simple geometry of in-line holography. The well-known twin-image problem is effectively circumvented by a simple and fast iterative reconstruction. The algorithm which combines elements of the classical Gerchberg-Saxton scheme and the hybrid-input-output algorithm is optimized for phase-contrast samples, well-justified for imaging of cells at multi-keV photon energies. The experimental scheme allows for a quantitative phase reconstruction from a single holographic image without detailed knowledge of the complex illumination function incident on the sample, as demonstrated for freeze-dried cells of the eukaryotic amoeba Dictyostelium discoideum. The accessible resolution range is explored by simulations, indicating that resolutions on the order of 20 nm are within reach applying illumination times on the order of minutes at present synchrotron sources.}, language = {en} } @article{ToalaOskinovaGonzalezGalanetal.2016, author = {Toala, Jes{\´u}s Alberto and Oskinova, Lida and Gonzalez-Galan, Ana and Guerrero, Mart{\´i}n A. and Ignace, R. and Pohl, Martin}, title = {X-RAY OBSERVATIONS OF BOW SHOCKS AROUND RUNAWAY O STARS. THE CASE OF zeta OPH AND BD+43 degrees 3654}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {821}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0004-637X}, doi = {10.3847/0004-637X/821/2/79}, pages = {9}, year = {2016}, abstract = {Non-thermal radiation has been predicted within bow shocks around runaway stars by recent theoretical works. We present X-ray observations toward the runaway stars zeta Oph by Chandra and Suzaku and of BD+43 degrees 3654 by XMM-Newton to search for the presence of non-thermal X-ray emission. We found no evidence of non-thermal emission spatially coincident with the bow shocks; nonetheless, diffuse emission was detected in the vicinity of zeta Oph. After a careful analysis of its spectral characteristics, we conclude that this emission has a thermal nature with a plasma temperature of T approximate to 2 x 10(6) K. The cometary shape of this emission seems to be in line with recent predictions of radiation-hydrodynamic models of runaway stars. The case of BD+43 degrees 3654 is puzzling, as non-thermal emission has been reported in a previous work for this source.}, language = {en} } @article{OskinovaFeldmeierHamann2003, author = {Oskinova, Lida and Feldmeier, Achim and Hamann, Wolf-Rainer}, title = {X-ray line profiles from structured stellar winds}, isbn = {1-58381-133-8}, year = {2003}, abstract = {Absorbing material compressed in a number of thin shells is effectively less opaque for X-rays than smoothly distributed gas. The calculated X-ray emission line profiles are red-shifted if the emission arises from the starward side of the shells.}, language = {en} }