A5068988311- Astrophysical Phenomena and Observations
- Superconducting and THz Device Technology
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Physics of Superconductivity and Magnetism
- Superconducting Materials and Applications
- Calibration and Measurement Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Astrophysics and Star Formation Studies
- High-pressure geophysics and materials
- Advanced Thermodynamic Systems and Engines
- Nuclear Physics and Applications
- Gamma-ray bursts and supernovae
- Advanced Semiconductor Detectors and Materials
- Atomic and Molecular Physics
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Radiation Detection and Scintillator Technologies
- Adaptive optics and wavefront sensing
- Scientific Measurement and Uncertainty Evaluation
- Microwave and Dielectric Measurement Techniques
- thermodynamics and calorimetric analyses
SRON Netherlands Institute for Space Research
2014-2024
VTT Technical Research Centre of Finland
2021
Tieto (Finland)
2021
University of Minnesota
1980
We analyze a 137 ks exposure X-ray spectrum of the Seyfert 1 galaxy NGC 5548 obtained with XMM-Newton Reflection Grating Spectrometer. Due to long time, is higher statistical quality than previous observations this AGN. Therefore, we detect for first time in inner-shell transitions from ions, and Unresolved Transition Array M-shell iron. The warm absorber found observation spans three orders magnitude ionization parameter. , which as lowly ionized detected UV band, . For column density...
The XMM-Newton spectra of the isolated neutron star RX J0720.4-3125 obtained over 4.5 years can be described by sinusoidal variations in inferred blackbody temperature, size emitting area and depth absorption line with a period years, which we suggest to precession star. Precession two hot spots different temperature size, probably not located exactly antipodal positions, may account for X-ray spectra, changes pulsed fraction, shape light curve phase-lag between soft hard energy bands...
We detect a gradual, long-term change in the shape of X-ray spectrum isolated neutron star RX J0720.4-3125, such that source can no longer be described as blackbody spectrum. The is accompanied by an energy-dependent pulse profile. If emission influenced magnetic field pulsar, these changes spectral may point to precession star.
We co-added the available XMM–Newton Reflection Grating Spectrometer (RGS) spectra for each of isolated X-ray pulsars RX J0720.4−3125, J1308.6+2127 (RBS1223), J1605.3+3249 and J1856.4−3754 (four members 'Magnificent Seven') 'Three Musketeers' Geminga, PSR B0656+14 B1055−52. confirm detection a narrow absorption feature at 0.57 keV in RGS J0720.4−3125 (including most recent observations). In addition, we found similar features (at 0.53 keV) maybe B1055−52 0.56 keV). The is broader than e.g....
We study the absorption and scattering of X-ray radiation by interstellar dust particles, which allows us to access physical chemical properties dust. The composition is not well understood, especially on densest sight lines Galactic Plane. X-rays provide a powerful tool in this study. present newly acquired laboratory measurements silicate compounds taken at Soleil synchrotron facility Paris using Lucia beamline. profiles resulting from campaign were used pilot model along line low-mass...
We report on the development and demonstration of a MHz frequency domain multiplexing (FDM) technology to read out arrays cryogenic transition edge sensor (TES) X-ray microcalorimeters. In our FDM scheme, TESs are AC-biased at different resonant frequencies in low range through an array high-$Q$ LC resonators. The current signals all summed superconducting quantum interference devices (SQUIDs). have demonstrated for readout 31 pixels using room temperature electronics, filters TES developed...
The resolve instrument onboard the X-Ray Imaging and Spectroscopy Mission (XRISM) consists of an array 6 × silicon-thermistor microcalorimeters cooled down to 50 mK a high-throughput x-ray mirror assembly (XMA) with focal length 5.6 m. XRISM is recovery mission ASTRO-H/Hitomi, Resolve rebuild ASTRO-H soft spectrometer (SXS) Soft X-ray Telescope (SXT) that achieved energy resolution ∼5 eV FWHM on orbit, several important changes based lessons learned from ASTRO-H. flight models Dewar...
Understanding the chemistry of interstellar medium (ISM) is fundamental for comprehension Galactic and stellar evolution. X-rays provide an excellent way to study dust chemical composition crystallinity along different sight lines in Galaxy. In this work, we grain diffuse regions ISM soft X-ray band (<1 keV). We use newly calculated extinction cross sections obtained from laboratory data order investigate oxygen K iron L shell absorption. explore XMM-Newton Chandra spectra five low-mass...
High resolution X-ray spectra of the Reflection Grating Spectrometer (RGS) on board XMM satellite are used to resolve oxygen K absorption edge. By combining low and high extinction sources, observed edge can be split in true interstellar (ISM) instrumental absorption. The detailed ISM structure closely follows neutral as derived by theoretical R-matrix calculations. However, position requires a wavelength shift. In addition RGS is presented. All results verified comparing subset Chandra...
We are developing the frequency domain multiplexing (FDM) read-out of transition-edge sensor (TES) microcalorimeters for X-ray Integral Field Unit (X-IFU) instrument on board future European X-Ray observatory Athena. The X-IFU consists an array ~3840 TESs with a high quantum efficiency (>90 %) and spectral resolution Δ<i>E</i>=2.5 eV @ 7 keV (<i>E</i>/ Δ<i>E</i> ~2800). FDM is currently baseline readout system instrument. Using quality factor LC filters room temperature...
The Resolve instrument aboard the X-ray Imaging and Spectroscopy Mission (XRISM) is a 36-pixel microcalorimeter spectrometer that provides non-dispersive spectroscopy with 5 eV spectral resolution in soft x-ray waveband. has requirement to provide absolute energy-scale calibration of ± 2 from 0.3–12 keV. In this manuscript we describe our ground strategy results subset campaigns, including discussion improvements energy scale compared Hitomi's. These include low-energy band below 4 keV...
<i>Context. <i/>In the past, isolated, radio-quiet neutron star RX J0720.4-3125 showed variations in its spectral parameters (apparent radius, temperature of emitting area and equivalent width absorption feature) seen X-ray spectra, not only during spin period 8.39 s, but also over time scales years. New observations with XMM-Newton extend coverage to about 7.5 years latest pointing performed November 2007. Out a total fourteen available EPIC-pn datasets, eleven have been obtained an...
RX J0720.4-3125 is the most peculiar object among a group of seven isolated X-ray pulsars (the so-called Magnificent Seven), since it shows long-term variations its spectral and temporal properties on time-scales years.This behaviour was explained by different authors either free precession (with 7 or 14 yr period) possibly glitch that occurred around MJD = 528 66 ± 73 d.We analysed our recent XMM-Newton Chandra observations in order to further monitor this neutron star.With new data sets,...
We observed the isolated neutron star RX J0720.4-3125 with Chandra's Low Energy Transmission Grating Spectrometer, following XMM-Newton discovery of long-term spectral evolution this source. The new observation shows that spectrum has continued to change in course 5 months. It remained hard, similar last observation, but strong depression at long wavelengths disappeared. Contrary observations, Chandra flux increase short wavelength and decrease do not necessarily occur simultaneously.
The conversion of atomic helium ions into molecular was studied in pure and helium-neon mixtures containing between 0.1 at.% 50 neon. experiments showed that the termolecular reaction, ${\mathrm{He}}^{+}+2\mathrm{He}\ensuremath{\rightarrow}\mathrm{He}_{2}^{}{}_{}{}^{+}+\mathrm{He}$, is augmented by four-body reaction ${\mathrm{He}}^{+}+3\mathrm{He}\ensuremath{\rightarrow}\mathrm{products}$, where products could include either $\mathrm{He}_{2}^{}{}_{}{}^{+}$ or $\mathrm{He}_{3}^{}{}_{}{}^{+}$...