Werner, K., Rauch, T., Kruk, J. W.
For the first time, we have identified photospheric emission lines in the far-UV spectrum of a white dwarf. They were discovered in the Far Ultraviolet Spectroscopic Explorer spectrum of the hot...
In ultrarelativistic heavy ion collisions, the multiplicity of multi-strange baryons per participating nucleon increases with centrality in a different fashion for different systems and energies. At...
Spectral modeling of gaseous metal disks around DAZ white dwarfs (2008)
Werner, K., Nagel, T., Rauch, T.
We report on our attempt for the first non-LTE modeling of gaseous metal disks around single DAZ white dwarfs recently discovered by Gaensicke et al. and thought to originate from a disrupted...
Influence of Compton scattering on the broad-band X-ray spectra of intermediate polars (2008)
Suleimanov, V., Poutanen, J., Falanga, M., Werner, K.
The majority of cataclysmic variables observed in the hard X-ray energy band are intermediate polars where the magnetic field is strong enough to channel the accreting matter to the magnetic poles of...
Rauch, T., Reiff, E., Werner, K., Kruk, J. W.
Spectral analyses of H-deficient post-AGB stars have shown that a small group of four extremely hot objects exists which have almost pure He absorption-line spectra in the optical. These are...
UV and FUV spectroscopy of the hybrid PG 1159-type central star NGC 7094 (2008)
Ziegler, M., Rauch, T., Reiff, E., Werner, K., Kruk, J. W., Oliveira, C. M.
Previous studies aiming at the iron-abundance determination in three PG 1159 stars (K 1-16, PG 1159-035, NGC 7094) and a [WC]-PG 1159 transition star (Abell 78) have revealed that no object shows any...
Search For Iron, Nickel, and Fluorine in PG1159 Stars (2008)
Reiff, E., Rauch, T., Werner, K., Kruk, J. W., Koesterke, L.
A possible origin of the iron-deficiency in PG1159 stars could be neutron captures on Fe nuclei. A nickel overabundance would corroborate this idea. Consequently we are looking for nickel lines in...
Latest Results from the Air Shower Simulation Programs CORSIKA and CONEX (2008)
Pierog, T., Engel, R., Heck, D., Ostapchenko, S., Werner, K.
Interpretation of EAS measurements strongly depends on detailed air shower simulations. The uncertainty in the prediction of shower observables for different primary particles and energies is...
The focal-plane instruments on board WSO-UV (2008)
Pagano, I., Sachkov, M., Huang, M., Kappelmann, N., Scuderi, S., ...
Dedicated to spectroscopic and imaging observations of the ultraviolet sky, the World Space Observatory for Ultraviolet Project is a Russia led international collaboration presently involving also...
Heavy-ion collisions at the LHC-Last call for predictions (2008)
Armesto, N., Borghini, N., Jeon, S., Wiedemann, U. A., Abreu, S., Akkelin, S. V., ...
This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute 'Heavy Ion Collisions at the LHC - Last...
Justus, E., Rischka, K., Wishart, J.F., Werner, K., Gabel, D.
Herein we report a new class of low-melting ionic liquids (IL) that consist of N,N,N-trialkylammonioundecahydrododecaborates(1-) as the anion and a range of cations. The cations include the common...
Bartels, J., Borras, K., Diehl, M., Jung, H., Abramowicz, H., Albacete, J., ...
Proceedings of the 12th International Conference on Elastic and Diffractive Scattering (Blois Workshop) - Forward Physics and QCD
Werner, K., Barnstedt, J., Gringel, W., Kappelmann, N., Becker-Ross, H., Florek, S., ...
The World Space Observatory Ultraviolet (WSO/UV) is a multi-national project grown out of the needs of the astronomical community to have future access to the UV range. WSO/UV consists of a single UV...
Heavy Ion Collisions at the LHC - Last Call for Predictions (2007)
Abreu, S., Akkelin, S. V., Alam, J., Albacete, J. L., Andronic, A., Antonov, D., ...
This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute 'Heavy Ion Collisions at the LHC - Last...
Elemental Abundances in PG1159 Stars (2007)
Werner, K., Rauch, T., Reiff, E., Kruk, J. W.
The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogen...
KPD0005+5106: Hottest DO White Dwarf Much Hotter Than Assumed (2007)
Werner, K., Rauch, T., Kruk, J. W.
KPD0005+5106 is the hottest known helium-rich white dwarf. We have identified NeVIII lines in UV and optical spectra and conclude that it is significantly hotter than previously thought, namely...
A Macroscopic Description of Coherent Geo-Magnetic Radiation from Cosmic Ray Air Showers (2007)
Scholten, O., Werner, K., Rusydi, F.
We have developed a macroscopic description of coherent electro-magnetic radiation from air showers initiated by ultra-high energy cosmic rays due to the presence of the geo-magnetic field. This...
Synthetic NLTE accretion disc spectra for the dwarf nova SS Cyg during an outburst cycle (2007)
Kromer, M., Nagel, T., Werner, K.
Dwarf nova outbursts result from enhanced mass transport through the accretion disc of a cataclysmic variable system. We assess the question of whether these outbursts are caused by an enhanced mass...
Asteroseismological constraints on the coolest GW Vir variable star (PG 1159-type)PG 0122+200 (2007)
Córsico, A. H., Bertolami, M. M. Miller, Althaus, L. G., Vauclair, G., Werner, K.
We present an asteroseismological study on PG 0122+200, the coolest known pulsating PG1159 (GW Vir) star. Our results are based on an augmented set of the full PG1159 evolutionary models recently...
Extended Air Shower Simulations Based on EPOS (2007)
We discuss air shower simulations based on the EPOS hadronic interaction model. A remarkable feature is the fact that the number of produced muons is considerably larger compared to other interaction...
Rauch, T., Ziegler, M., Werner, K., Kruk, J. W., Oliveira, C. M., Putte, D. Vande, ...
LS V +4621 is the DAO-type central star of the planetary nebula Sh 2-216. We perform a comprehensive spectral analysis of high-resolution, high-S/N ultraviolet observations obtained with FUSE and...
On the role of energy conservation in high-energy nuclear scattering (2007)
Drescher, H.J., Hladik, M., Ostapchenko, S., Pierog, T., Werner, K.
We argue that the most commonly used models for nuclear scattering at ultra-relativistic energies do not treat energy conservation in a consistent fashion. Demanding theoretical consistency as a...
On the role of energy conservation in high-energy nuclear scattering (2007)
Drescher, H.J., Hladik, M., Ostapchenko, S., Pierog, T., Werner, K.
We argue that the most commonly used models for nuclear scattering at ultra-relativistic energies do not treat energy conservation in a consistent fashion. Demanding theoretical consistency as a...
On the role of energy conservation in high-energy nuclear scattering (2007)
Drescher, H.J., Hladik, M., Ostapchenko, S., Pierog, T., Werner, K.
We argue that the most commonly used models for nuclear scattering at ultra-relativistic energies do not treat energy conservation in a consistent fashion. Demanding theoretical consistency as a...
Hadron Production in Proton-Proton Scattering in NEXUS3 (2007)
Liu, F.M., Pierog, T., Aichelin, J., Werner, K.
Using the recently introduced model NEXUS 3, we calculate for proton-proton, neutron-proton and antiproton-proton collisions the excitation function of particle yields and of average transverse...
Limits on iron-dominated fallback disk in SN 1987A (2007)
Werner, K., Nagel, T., Rauch, T.
The non-detection of a point source in SN1987A imposes an upper limit for the optical luminosity of L=2L_sun. This limits the size of a possible fallback disk around the stellar remnant. Assuming a...
Nuclear Scattering at Very High Energies (2007)
Werner, K., Drescher, H. J., Ostapchenko, S., Pierog, T.
We discuss the current understanding of nuclear scattering at very high energies. We point out several serious inconsistencies in nowadays models, which provide big problems for any interpretation of...
One-dimensional Hybrid Approach to Extensive Air Shower Simulation (2007)
Bergmann, T., Engel, R., Heck, D., Kalmykov, N.N., Ostapchenko, S., Pierog, T., ...
An efficient scheme for one-dimensional extensive air shower simulation and its implementation in the program CONEX are presented. Explicit Monte Carlo simulation of the high-energy part of hadronic...
Emergent model spectra of neutron star atmospheres are widely used to fit the observed soft X-ray spectra of different types of isolated neutron stars. We investigate the effect of Compton scattering...
Drescher, H.J., Hladik, M., Ostapchenko, S., Werner, K.
Our ultimate goal is the construction of a model for interactions of two nuclei in the energy range between several tens of GeV up to several TeV per nucleon in the centre-of-mass system. Such...
Werner, K., Rauch, T., Kruk, J. W.
We report the first discovery of argon in hot evolved stars and white dwarfs. We have identified the ArVII 1063.55A line in some of the hottest known (Teff=95000-110000 K) central stars of planetary...
New facts about muon production in Extended Air Shower simulations (2007)
Whereas air shower simulations are very valuable tools for interpreting cosmic ray data, there is a long standing problem: is seems to be impossible to accommodate at the same time the longitudinal...
Radiative transfer in CV disk winds (2007)
Nagel, T., Werner, K., Feldmeier, Achim
Mass accretion onto compact objects through accretion disks is a common phenomenon in the universe. It is seen in all energy domains from active galactic nuclei through cataclysmic variables (CVs) to...
Radiative transfer in CV disk winds (2007)
Nagel, T., Werner, K., Feldmeier, Achim
Mass accretion onto compact objects through accretion disks is a common phenomenon in the universe. It is seen in all energy domains from active galactic nuclei through cataclysmic variables (CVs) to...
Importance of Compton scattering to radiation spectra of isolated neutron stars (2006)
Model atmospheres of isolated neutron stars with low magnetic field are calculated with Compton scattering taking into account. Models with effective temperatures 1, 3 and 5 MK, with two values of...
Non-LTE Models for Neutron Star Atmospheres and Supernova-Fallback Disks (2006)
Werner, K., Nagel, T., Rauch, T., Suleimanov, V.
We describe our recent progress in modeling supernova-fallback disks and neutron star (NS) atmospheres. We present a first detailed spectrum synthesis calculation of a SN-fallback disk composed of...
Microcanonical pentaquark production in electron-positron annihilations (2006)
The existence of pentaquarks, namely baryonic states made up of four quarks and one antiquark, became questionable, because the candidates, i.e. the $\Theta^+$ peak, are seen in certain reactions,...
We present a phenomenological approach (EPOS), based on the parton model, but going much beyond, and try to understand proton-proton and deuteron-gold collisions, in particular the transverse...
New facts about muon production in Extended Air Shower simulations (2006)
Whereas air shower simulations are very valuable tools for interpreting cosmic ray data, there is a long standing problem: is seems to be impossible to accommodate at the same time the longitudinal...
Huegelmeyer, S. D., Dreizler, S., Werner, K., Krzesinski, J., Nitta, A., Kleinman, S. J.
The Sloan Digital Sky Survey has provided spectra of a large number of new PG 1159 stars and DO white dwarfs. This increase in known hot H-deficient compact objects significantly improves the...
High-resolution ultraviolet spectroscopy of PG1159-035 with HST and FUSE (2006)
Jahn, D., Rauch, T., Reiff, E., Werner, K., Kruk, J. W., Herwig, F.
PG1159-035 is the prototype of the PG1159 spectral class which consists of extremely hot hydrogen-deficient (pre-) white dwarfs. It is also the prototype of the GW Vir variables, which are non-radial...
Córsico, A. H., Althaus, L. G., Bertolami, M. M. Miller, Werner, K.
We present asteroseismological inferences on RX J2117.1+3412, the hottest known pulsating PG1159 star. Our results are based on full PG1159 evolutionary models recently presented by Miller Bertolami...
HST and FUSE Spectroscopy of the DAO-type Central Star LS V+4621 (2006)
Rauch, T., Ziegler, M., Werner, K., Kruk, J. W.
The DAO-type white dwarf LS V+4621 is the hydrogen-rich central star of the possible planetary nebula Sh 2-216. We have taken high-resolution, high-S/N ultraviolet spectra with STIS aboard the HST...
Ziegler, M., Rauch, T., Werner, K., Kruk, J. W., Oliveira, C.
The far-ultraviolet spectrum of the DAO White Dwarf LS V+4621, the exciting star of the possible planetary nebula Sh 2-216,is strongly contaminated by absorption features from the interstellar medium...
Soft X-ray Spectroscopy of the Hot DA White Dwarf LB1919 and the PG1159 Star PG1520+525 (2006)
Werner, K., Drake, J. J., Rauch, T., Schuh, S., Gautschy, A.
We have performed soft X-ray spectroscopy of two hot white dwarfs with the Chandra observatory using the Low Energy Transmission Grating. The first target is the hot DA white dwarf LB1919 (Teff=69000...
12th International Conference on Elastic and Diffractive Scattering : Forward Physics and QCD (2006)
Bartels, J, Borras, K, Diehl, M, Jung, H, Abramowicz, H, Albacete, J, ...
Non-LTE modeling of supernova-fallback disks (2006)
Werner, K., Nagel, T., Rauch, T.
We present a first detailed spectrum synthesis calculation of a supernova-fallback disk composed of iron. We assume a geometrically thin disk with a radial structure described by the classical...
Screening Corrections In Simulating Heavy Ion Collisions (2006)
Pierog, T., Drescher, H.J., Ostapchenko, S., Werner, K.
One year ago, we presented a new approach to treat hadronic interactions for the initial stage of nuclear collisions. It is an effective theory based on the Gribov-Regge formalism, where the internal...
Models for RHIC and LHC: New Developments (2006)
Werner, K., Drescher, H. J., Ostapchenko, S., Pierog, T.
We outline inconsistencies in presently used models for high energy nuclear scattering, which make their application quite unreliable. Many \"successes\" are essentially based on an artificial...
Tools for RHIC: Review of Models (2006)
We discuss the present status of microscopic models for RHIC, with an emphasis on models being realized via the Monte Carlo technique. This review is to a large extent based on the OSCAR3 workshop,...
One-dimensional Hybrid Approach to Extensive Air Shower Simulation (2006)
Bergmann, T., Engel, R., Heck, D., Kalmykov, N. N., Ostapchenko, S., Pierog, T., ...
An efficient scheme for one-dimensional extensive air shower simulation and its implementation in the program CONEX are presented. Explicit Monte Carlo simulation of the high-energy part of hadronic...
Huegelmeyer, S. D., Dreizler, S., Homeier, D., Krzesinski, J., Werner, K., Nitta, A., ...
Context: The Sloan Digital Sky Survey Data Release 4 has provided spectra of several new PG 1159 stars and DO white dwarfs. This increase in known hot H-deficient compact objects significantly...
EMMA Air-Ground Operational Service and Environmental Description (OSED-update) (2006)
Moller, M., Jakobi, J., Berge, P., Dairay, G., Isambert, E., Pina Calafi, P., ...
The OSED Update (D1. 3.1u) document covers the specification of the operational services related to A-SMGCS from the perspective of ATC Controllers (ATCOs), Flight Crews and Vehicle Drivers and in...
Proton-proton and deuteron-gold collisions at RHIC (2006)
Werner, K., Liu, F. M., Pierog, T.
We try to understand recent data on proton-proton and deuteron-gold collisions at RHIC, employing a modified parton model approach.
Werner, K., Jahn, D., Rauch, T., Reiff, E., Herwig, F., Kruk, J. W.
The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogen...
NLTE spectral analysis of GW Vir pulsators (2006)
Reiff, E., Jahn, D., Rauch, T., Werner, K., Kruk, J. W., Herwig, F.
GW Vir variables are the pulsating members in the spectroscopic class of PG 1159 stars. In order to understand the characteristic differences between pulsating and non-pulsating PG 1159 stars, we...
Werner, K., Nagel, T., Rauch, T., Hammer, N. J., Dreizler, S.
We present new medium-resolution high-S/N optical spectra of the ultracompact low-mass X-ray binaries 4U0614+091 and 4U1626-67, taken with the ESO Very Large Telescope. They are pure emission line...
First Results of Fast One-dimensional Hybrid Simulation of EAS Using CONEX (2005)
Pierog, T., Alekseeva, M. K., Bergmann, T., Chernatkin, V., Engel, R., Heck, D., ...
A hybrid simulation code is developed that is suited for fast one-dimensional simulations of shower profiles, including fluctuations. It combines the Monte Carlo simulation of high energy...
We review the observed properties of extremely hot hydrogen-deficient post-AGB stars of spectral type [WC] and PG1159. Their H-deficiency is probably caused by a (very) late helium-shell flash or a...
Werner, K., Chernatkin, V., Engel, R., Kalmykov, N. N., Ostapchenko, S., Pierog, T.
We present an introductory lecture on general features of cosmic rays, for non-experts, and some recent developments concerning cascade equations for air shower developments.
A New String Model: NEXUS 3 (2005)
Werner, K., Liu, F. M., Ostapchenko, S., Pierog, T.
After discussing conceptual problems with the conventional string model, we present a new approach, based on a theoretically consistent multiple scattering formalism. First results for proton-proton...
Werner, K., Drescher, H. J., Ostapchenko, S., Pierog, T.
The interpretation of experimental results at RHIC and in the future also at LHC requires very reliable and realistic models. Considerable effort has been devoted to the development of such models...
Inconsistencies in Models for RHIC and LHC (2005)
Werner, K., Drescher, H. J., Ostapchenko, S., Pierog, T.
The interpretation of experimental results at RHIC and in the future also at LHC requires very reliable and realistic models. Considerable effort has been devoted to the development of such models...
Spectral analyses of DO white dwarfs and PG1159 stars from the Sloan Digital Sky Survey (2005)
Huegelmeyer, S. D., Dreizler, S., Werner, K., Krzesinski, J., Nitta, A., Kleinman, S. J.
We present a model atmosphere analysis of ten new DO white dwarfs and five new PG 1159 stars discovered in the Sloan Digital Sky Survey DR1, DR2 and DR3. This is a significant increase in the number...