A5011834797- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Magnetic properties of thin films
- Galaxies: Formation, Evolution, Phenomena
- Magnetic Properties and Applications
- Rare-earth and actinide compounds
- Physics of Superconductivity and Magnetism
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Astrophysics and Star Formation Studies
- Advanced Chemical Physics Studies
- Heusler alloys: electronic and magnetic properties
- Magnetic Properties of Alloys
- Iron-based superconductors research
- High-pressure geophysics and materials
- Radio Wave Propagation Studies
- Particle Accelerators and Free-Electron Lasers
- ZnO doping and properties
- Atmospheric and Environmental Gas Dynamics
- Nuclear Materials and Properties
- Electronic and Structural Properties of Oxides
- Stellar, planetary, and galactic studies
- Material Properties and Processing
- Photosynthetic Processes and Mechanisms
- Nanofabrication and Lithography Techniques
Karlsruhe Institute of Technology
2024
Nanosystems Initiative Munich
2024
Max Planck Institute for Radio Astronomy
2012-2015
Max Planck Society
2013-2015
Netherlands Institute for Radio Astronomy
2014
Max Planck Innovation
2013
University of Konstanz
1994-2005
Technical University of Darmstadt
1995-1999
Max Planck Institute of Biochemistry
1998
Darmstadt University of Applied Sciences
1984-1997
Faraday rotation measurements using the current and next generation of low-frequency radio telescopes will provide a powerful probe astronomical magnetic fields. However, achieving full potential these requires accurate removal time-variable ionospheric contribution. We present ionFR, code that calculates amount for specific epoch, geographic location, line-of-sight. ionFR uses number publicly available, GPS-derived total electron content maps most recent release International Geomagnetic...
M87 is a giant elliptical galaxy located in the centre of Virgo cluster, which harbours supermassive black hole mass 6.4x10^9 M_sun, whose activity responsible for extended (80 kpc) radio lobes that surround galaxy. The energy generated by matter falling onto central ejected and transferred to intra-cluster medium via relativistic jet morphologically complex systems buoyant bubbles, rise towards edges halo. Here we present first observations made with new Low-Frequency Array (LOFAR) at...
The low frequency array (LOFAR), is the first radio telescope designed with capability to measure emission from cosmic-ray induced air showers in parallel interferometric observations. In $\sim 2\,\mathrm{years}$ of observing, 405 events energy range $10^{16} - 10^{18}\,\mathrm{eV}$ have been detected band $30 80\,\mathrm{MHz}$. Each these registered up $\sim1000$ independent antennas resulting measurements unprecedented detail. This article describes dataset, as well analysis pipeline, and...
The grand-design spiral galaxy M51 was observed with the LOFAR High Frequency Antennas (HBA) and imaged in total intensity polarisation. This observation covered frequencies between 115 MHz 175 MHz. We produced an image of emission at mean frequency 151 20 arcsec resolution 0.3 mJy rms noise, which is most sensitive a below 300 so far. integrated spectrum radio described well by power law, while flat spectral indices central region indicate thermal absorption. observe that disk extends out...
To study centrosome motility and the interaction of microtubules with cell cortex in mitotic, post-mitotic interphase cells, (alpha)-tubulin was tagged Dictyostelium discoideum green fluorescent protein. Multinucleate cells formed by myosin II-null mutants proved to be especially suited for analysis control cleavage furrow formation microtubule system. After docking mitotic apparatus onto during anaphase, surface is activated form ruffles on top asters that emanate from centrosomes. Cleavage...
Air showers induced by cosmic rays create nanosecond pulses detectable at radio frequencies. These have been measured successfully in the past few years LOw Frequency ARray (LOFAR) and are used to study properties of rays. For a complete understanding this phenomenon underlying physical processes, an absolute calibration detecting antenna system is needed. We present three approaches that were check improve model LOFAR provide whole for air shower measurements. Two methods based on...
The existence of double-double radio galaxies (DDRGs) is evidence for recurrent jet activity in AGN, as expected from standard accretion models. A detailed study these rare sources provides new perspectives investigating the AGN duty cycle, AGN-galaxy feedback, and mechanisms. Large catalogues provide statistical information about evolution radio-loud population out to high redshifts. Using wide-field imaging with LOFAR telescope, we both a well-known DDRG well large number field view. We...
Abstract The origin of magnetic fields in the Universe is an open problem astro‐physics and fundamental physics. Polarization observations with forthcoming large radio telescopes will a new era observation should help to understand their origin. At low frequencies, LOFAR (10–240 MHz) allow us map structure weak outer regions halos galaxies, galaxy clusters Milky Way via synchrotron emission. Even weaker can be measured at frequencies Faraday rotation measures. A detailed view local derived...
We present the first detection of carbon radio recombination line absorption along sight to Cygnus A. The observations were carried out with LOw Frequency ARray in 33 57 MHz range. These low frequency provide us a new study diffuse, neutral gas our Galaxy. To knowledge this is time that foreground Milky Way has been observed against bright extragalactic background source. By stacking 48 $\alpha$ lines range we detect signal-to-noise ratio about 5. average peak optical depth...
Cassiopeia A was observed using the Low-Band Antennas of LOw Frequency ARray (LOFAR) with high spectral resolution. This allowed a search for radio recombination lines (RRLs) along line-of-sight to this source. Five carbon-alpha RRLs were detected in absorption between 40 and 50 MHz signal-to-noise ratio > 5 from two independent LOFAR datasets. The derived line velocities (v_LSR ~ -50 km/s) integrated optical depths (~ 13 s^-1) our spectra, extracted over whole supernova remnant, are...
The magneto-optical properties of MnBi show some striking features which we address here by calculating the Kerr spectra pure MnBi, as well (X = Mn, Si, Al, O and Pt) (X, Y) (Al, Al) O), (Pt, Pt). This system compounds constitutes an example for demonstrate how much first-principles calculations can achieve our findings be used to advance knowledge origin properties. Our are based on local density functional approximation (LDA) augmented spherical wave (ASW) band structure method including...
We report the first observation of a weak ferromagnetic state Cr in Cr/Ru(0001) superlattices, based on magnetic hysteresis and corroborated by x-ray circular dichroism at CrL(2,3) edges. In situ reflection high-energy electron diffraction, K-edge polarized absorption investigations have shown that layers thinner than 8 angstroms adopt slightly distorted hcp structure, accompanied large atomic volume expansion up to 14% compared bcc packing volume. The expanded structure clearly induces...
The local atomic structure of CrPt3(111) thin films grown by molecular beam epitaxy at different temperatures (400 and 850 °C) has been investigated polarized x-ray absorption spectroscopy (XAS) the chromium K edge. Previous diffraction magnetic studies have revealed that °C present L12 chemically long range ordered are ferrimagnetic with occurrence perpendicular anisotropy (PMA). In contrast, 400 °C, which non-magnetic, do not show any indication L12-type order. From polarization dependence...