Related papers: On the iron Kalpha complex in magnetic cataclysmic…
Using the Hopkins Ultraviolet Telescope (HUT), we have obtained 850-1850 angstrom spectra of the magnetic cataclysmic variable star AM Her in the high state. These observations provide high time resolution spectra of AM Her in the FUV and…
The X-ray spectra of Active Galactic Nuclei (AGN) are complex and vary rapidly in time as seen in recent observations. Magnetic flares above the accretion disk can account for the extreme variability of AGN. They also explain the observed…
We present results from the spectral analysis of the Seyfert 1.9 galaxy MCG-5-23-16, based on ASCA, BeppoSAX, Chandra and XMM-Newton observations. The spectrum of this object shows a complex iron Kalpha emission line, which is best modeled…
The high-precision data available from the Kepler satellite allows us to venture in the study of the complex outer convective envelopes of solar-type stars. We use a seismic diagnostic, specialized for investigating the outer layers of…
We present an analysis of five Suzaku observations of the bright Seyfert1 galaxy IC 4329A. The broad energy band and high signal-to-noise ratio of the data give new constraints on the iron K alpha line profile and its relationship with the…
We present a high resolution X-ray spectrum of the iron K bandpass in MCG-6-30-15 based on a 522 ksec observation with Chandra's High Energy Transmission Grating Spectrometer. The Chandra spectrum is consistent with the presence of a…
We present the imaging and spectroscopic analysis of the combined Chandra ACIS-S observations of the Compton-thick Seyfert 2 galaxy NGC 4945. We performed a spatially-resolved spectroscopy of the circumnuclear environment of the source,…
In this work we reported the structural and electronic properties of the Heusler compound Co2FeGe using the AKAI-KKR code under the GGA approximation. We established that this material presents not only magnetic character but also has a…
Mapping magnetic fields is the key to resolving what remains an unclear physical picture of circumstellar magnetic fields in late-type evolved stars. Observations of linearly polarized emission from thermal molecular line transitions due to…
High-resolution X-ray spectra of $\pi\,$Aqr, a $\gamma\,$Cas-type star, obtained with the Chandra/HETG grating spectrometer, revealed emission lines of H-like ions of Mg, Si, S, and Fe, a strong, hard continuum, and a lack of He-like ions,…
We present Chandra HETG spectra of seven cataclysmic variables. We find that they divide unambiguously into two distinct types. Spectra of the first type are remarkably well fit by a simple cooling flow model, which assumes only…
Aims: We present a magnetic Doppler imaging study from all Stokes parameters of the cool, chemically peculiar star HD 24712. This is the very first such analysis performed at a resolving power exceeding 10^5. Methods: The analysis is…
The Ly-alpha line of He II at 304 \AA\ is one of the spectral lines of choice for EUV channels of narrow-band imagers on board space telescopes, which provide spectacular intensity images of the outer solar atmosphere. Since the magnetic…
In this paper we present a comprehensive survey of 41 X-ray binaries (10 HMXBs and 31 LMXBs) with Chandra, with specific emphasis on the Fe K region and the narrow Fe Kalpha line, at the highest resolution possible. We find that: a) The Fe…
A number of O stars are suspected to have (weak) magnetic fields because of the observed cyclical variability in their UV wind-lines. However, direct detections of these magnetic fields with optical spectropolarimetry have proven to be very…
We have analysed high-resolution spectra of 28 A and 22 F stars in the Kepler field, observed with the FIES spectrograph at the Nordic Optical Telescope. We provide spectral types, atmospheric parameters and chemical abundances for 50…
Quaternary Heusler alloys Co$_2$Cr$_{1-x}$Fe$_{x}$Al with varying Cr to Fe ratio $x$ were investigated experimentally and theoretically. The electronic structure and spectroscopic properties were calculated using the full relativistic…
[ABRIDGED] We examine the velocity structure in the gas associated with \ion{H}{1} in the damped Ly$\alpha$ absorption system at redshift $z=1.7764$ towards the QSO $1331+170$ using 21cm data, optical and STIS spectra. We find at least two,…
We confirm the detection of the relativistically broadened iron K-alpha emission at 6.4 keV with simultaneous Chandra HETGS and RXTE PCA observations. Heavily binned HETGS data show a disk line profile with parameters very similar to those…
We present Halpha spectropolarimetry observations of a sample of 23 Herbig Ae/Be stars. A change in the linear polarisation across Halpha is detected in a large fraction of the objects, which indicates that the regions around Herbig stars…