Reinsch, Klaus

[["dc.bibliographiccitation.artnumber","A42"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","562"],["dc.contributor.author","Traulsen, Imke"],["dc.contributor.author","Reinsch, K."],["dc.contributor.author","Schwope, Axel D."],["dc.contributor.author","Schwarz, R."],["dc.contributor.author","Walter, F. M."],["dc.contributor.author","Burwitz, Vadim"],["dc.date.accessioned","2018-11-07T09:44:00Z"],["dc.date.available","2018-11-07T09:44:00Z"],["dc.date.issued","2014"],["dc.description.abstract","Context. RS Cae is the third target in our series of XMM-Newton observations of soft X-ray-dominated polars. Aims. Our observational campaign aims to better understand and describe the multiwavelength data, the physical properties of the system components, and the short-and long-term behavior of the component fluxes in RS Cae. Methods. We employ stellar atmosphere, stratified accretion-column, and widely used X-ray spectral models. We fit the XMM-Newton spectra, model the multiband light curves, and opt for a mostly consistent description of the spectral energy distribution. Results. Our XMM-Newton data of RS Cae are clearly dominated by soft X-ray emission. The X-ray light curves are shaped by emission from the main accretion region, which is visible over the whole orbital cycle, interrupted only by a stream eclipse. The optical light curves are formed by cyclotron and stream emission. The XMM-Newton X-ray spectra comprise a black-body-like and a plasma component at mean temperatures of 36 eV and 7 keV. The spectral fits give evidence of a partially absorbing and a reflection component. Multitemperature models, covering a broader temperature range in the X-ray emitting accretion regions, reproduce the spectra appropriately well. Including archival data, we describe the spectral energy distribution with a combination of models based on a consistent set of parameters and derive a lower limit estimate of the distance d greater than or similar to 750 pc. Conclusions. The high bolometric soft-to-hard flux ratios and short-term variability of the (X-ray) light curves are characteristic of inhomogeneous accretion. RS Cae clearly belongs in the group of polars that show a very strong soft X-ray flux compared to their hard X-ray flux. The different black-body fluxes and similar hard X-ray and optical fluxes during the XMM-Newton and ROSAT observations show that soft and hard X-ray emission are not directly correlated."],["dc.identifier.doi","10.1051/0004-6361/201321383"],["dc.identifier.isi","000332161800016"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10906"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/34299"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","1432-0746"],["dc.rights","Goescholar"],["dc.rights.uri","https://goedoc.uni-goettingen.de/licenses"],["dc.title","Phase-resolved X-ray spectroscopy and spectral energy distribution of the X-ray soft polar RS Caeli"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A116"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","529"],["dc.contributor.author","Traulsen, Imke"],["dc.contributor.author","Reinsch, K."],["dc.contributor.author","Schwope, Axel D."],["dc.contributor.author","Burwitz, Vadim"],["dc.contributor.author","Dreizler, Stefan"],["dc.contributor.author","Schwarz, R."],["dc.contributor.author","Walter, F. M."],["dc.date.accessioned","2018-11-07T08:56:44Z"],["dc.date.available","2018-11-07T08:56:44Z"],["dc.date.issued","2011"],["dc.description.abstract","Context. On the basis of XMM-Newton observations, we investigate the energy balance of selected magnetic cataclysmic variables, which have shown an extreme soft-to-hard X-ray flux ratio in the ROSAT All-Sky Survey. Aims. We intend to establish the X-ray properties of the system components, their flux contributions, and the accretion geometry of the X-ray soft polar QS Tel. In the context of high-resolution X-ray analyses of magnetic cataclysmic variables, this study will contribute to better understanding the accretion processes on magnetic white dwarfs. Methods. During an intermediate high state of accretion of QS Tel, we have obtained 20 ks of XMM-Newton data, corresponding to more than two orbital periods, accompanied by simultaneous optical photometry and phase-resolved spectroscopy. We analyze the multi-wavelength spectra and light curves and compare them to former high-and low-state observations. Results. Soft emission at energies below 2 keV dominates the X-ray light curves. The complex double-peaked maxima are disrupted by a sharp dip in the very soft energy range (0.1-0.5 keV), where the count rate abruptly drops to zero. The EPIC spectra are described by a minimally absorbed black body at 20 eV and two partially absorbed MEKAL plasma models with temperatures around 0.2 and 3 keV. The black-body-like component arises from one mainly active, soft X-ray bright accretion region nearly facing the mass donor. Parts of the plasma emission might be attributed to the second, virtually inactive pole. High soft-to-hard X-ray flux ratios and hardness ratios demonstrate that the high-energy emission of QS Tel is substantially dominated by its X-ray soft component."],["dc.description.sponsorship","ESA; NASA; DLR [50 OR0501, 50OR0807]"],["dc.identifier.doi","10.1051/0004-6361/201016352"],["dc.identifier.isi","289557200124"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9232"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23218"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","XMM-Newton observations of the X-ray soft polar QS Telescopii"],["dc.title.original","9232"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","193"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.lastpage","198"],["dc.bibliographiccitation.volume","481"],["dc.contributor.author","Burwitz, Vadim"],["dc.contributor.author","Reinsch, K."],["dc.contributor.author","Greiner, J."],["dc.contributor.author","Meyer-Hofmeister, E."],["dc.contributor.author","Meyer, Franc"],["dc.contributor.author","Walter, F. M."],["dc.contributor.author","Mennickent, R. E."],["dc.date.accessioned","2018-11-07T11:16:20Z"],["dc.date.available","2018-11-07T11:16:20Z"],["dc.date.issued","2008"],["dc.description.abstract","Context. The supersoft X-ray binary RXJ0513.9-6951 shows cyclic changes between optical-low/X-ray-on states and optical-high /X-ray-off states. It is supposed to be accreting close to the Eddington-critical limit and driven by \"accretion wind evolution\". Aims. We seek to derive the variations in the characteristic time scales of the long-term optical light curve and to determine the implications for the physical parameters of the system. Methods. We used existing and new optical monitoring observations covering a total time span of 14 years and compared the durations of the low and high states with the model calculations of Hachisu & Kato. Results. The cycle lengths and especially the durations of the optical high states show a longterm modulation with variations that, according to the accretion wind evolution model, would imply variations in the mass transfer rate by a factor of 5 on timescales of years."],["dc.identifier.doi","10.1051/0004-6361:20067010"],["dc.identifier.fs","513456"],["dc.identifier.isi","000254195200035"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9953"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54562"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","1432-0746"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Variability in the cycle length of the supersoft source RX J0513.9-6951"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A76"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","516"],["dc.contributor.author","Traulsen, Imke"],["dc.contributor.author","Reinsch, K."],["dc.contributor.author","Schwarz, R."],["dc.contributor.author","Dreizler, Stefan"],["dc.contributor.author","Beuermann, Klaus"],["dc.contributor.author","Schwope, Axel D."],["dc.contributor.author","Burwitz, Vadim"],["dc.date.accessioned","2018-11-07T08:42:26Z"],["dc.date.available","2018-11-07T08:42:26Z"],["dc.date.issued","2010"],["dc.description.abstract","Context. The energy balance of cataclysmic variables with strong magnetic fields is a central subject in understanding accretion processes on magnetic white dwarfs. With XMM-Newton, we perform a spectroscopic and photometric study of soft X-ray selected polars during their high states of accretion. Aims. On the basis of X-ray and optical observations of the magnetic cataclysmic variable AI Tri, we derive the properties of the spectral components, their flux contributions, and the physical structure of the accretion region in soft polars. Methods. We use multi-temperature approaches in our xspec modeling of the X-ray spectra to describe the physical conditions and the structures of the post-shock accretion flow and the accretion spot on the white-dwarf surface. In addition, we investigate the accretion geometry of the system by completing a timing analysis of the photometric data. Results. Flaring soft X-ray emission from the heated surface of the white dwarf dominates the X-ray flux during roughly 70% of the binary cycle. This component deviates from a single black body and can be described by a superimposition of mildly absorbed black bodies with a Gaussian temperature distribution between kT(bb,low) := 2 eV and kT(bb,high) = 43.9(-32)(+3.3) eV, and N(H,ISM) = 1.5(-0.7)(+0.8) x 10(20) cm(-2). In addition, weaker hard X-ray emission is visible nearly all the time. The spectrum from the cooling post-shock accretion flow is most closely fitted by a combination of thermal plasma MEKAL models with temperature profiles adapted from prior stationary two-fluid hydrodynamic calculations. The resulting plasma temperatures lie between kT(MEKAL,low) = 0.8(-0.2)(+0.4) keV and kT(MEKAL,high) = 20.0(-6.1)(+9.9) keV; additional intrinsic, partial-covering absorption is on the order of N(H,int) = 3.3(1.2)(+2.5) x 10(23) cm(-2). The soft X-ray light curves show a dip during the bright phase, which can be interpreted as self-absorption in the accretion stream. Phase-resolved spectral modeling supports the picture of one-pole accretion and self-eclipse. One of the optical light curves corresponds to an irregular mode of accretion. During a short XMM-Newton observation at the same epoch, the X-ray emission of the system is clearly dominated by the soft component."],["dc.description.sponsorship","DLR"],["dc.identifier.doi","10.1051/0004-6361/200913201"],["dc.identifier.fs","581081"],["dc.identifier.isi","280275400091"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9406"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19701"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","X-ray spectroscopy and photometry of the long-period polar AI Trianguli with XMM-Newton"],["dc.title.original","9406"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","271"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.lastpage","279"],["dc.bibliographiccitation.volume","442"],["dc.contributor.author","Schwarz, R."],["dc.contributor.author","Reinsch, K."],["dc.contributor.author","Beuermann, Klaus"],["dc.contributor.author","Burwitz, Vadim"],["dc.date.accessioned","2018-11-07T10:55:06Z"],["dc.date.available","2018-11-07T10:55:06Z"],["dc.date.issued","2005"],["dc.description.abstract","Using XMM-Newton we have obtained the first continuous X-ray observation covering a complete orbit of the longest period polar, V1309 Ori. The X-ray light curve is dominated by a short, bright phase interval with EPIC pn count rates reaching up to 15 cts s(-1) per 30 s resolution bin. The bright phase emission is well described by a single blackbody component with kT(bb) = ( 45 +/- 3) eV. The absence of a bremsstrahlung component at photon energies above 1 keV yields a flux ratio F-bb/F-br >= 6700. This represents the most extreme case of a soft X-ray excess yet observed in an AM Herculis star. The bright, soft X-ray emission is subdivided into a series of individual flare events supporting the hypothesis that the soft X-ray excess in V1309 Ori is caused by accretion of dense blobs carrying the energy into sub-photospheric layers. On average, the flares have rise and fall times of 10 s. In addition to the bright phase emission, a faint, hard X-ray component is visible throughout the binary orbit with an almost constant count rate of 0.01 cts s(-1). Spectral modelling indicates that this emission originates from a complex multi-temperature plasma. At least three components of an optically thin plasma with temperatures kT = 0.065, 0.7, and 2.9 keV are required to fit the observed flux distribution. The faint phase emission is occulted during the optical eclipse. Eclipse ingress lasts about 15 - 20 min and is substantially prolonged beyond nominal ingress of the white dwarf. This and the comparatively low plasma temperature provide strong evidence that the faint-phase emission is not thermal bremsstrahlung from a post-shock accretion column above the white dwarf. A large fraction of the faint-phase emission is ascribed to the spectral component with the lowest temperature and could be explained by scattering of photons from the blackbody component in the infalling material above the accretion region. The remaining hard X-ray flux could be produced in the coupling region, so far unseen in other AM Herculis systems."],["dc.identifier.doi","10.1051/0004-6361:20053560"],["dc.identifier.fs","38264"],["dc.identifier.isi","232230600024"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9856"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49712"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","XMM-Newton observation of the long-period polar V1309 Orionis: the case for pure blobby accretion"],["dc.title.original","9856"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]