J. S. Kaastra
A5007006031- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Atomic and Molecular Physics
- X-ray Spectroscopy and Fluorescence Analysis
- Solar and Space Plasma Dynamics
- Pulsars and Gravitational Waves Research
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Advanced X-ray Imaging Techniques
- Particle Detector Development and Performance
- Astro and Planetary Science
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Scientific Measurement and Uncertainty Evaluation
- Magnetic confinement fusion research
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
SRON Netherlands Institute for Space Research
2016-2025
Leiden University
2015-2024
Leiden Observatory
2016-2024
Japan Aerospace Exploration Agency
2010-2024
Institute of Space and Astronautical Science
2024
Utrecht University
2010-2020
Saitama University
2020
Tokyo Metropolitan University
2020
Goddard Space Flight Center
2010-2018
Johns Hopkins University
2014
The ESA X-ray Multi Mirror mission, XMM-Newton, carries two identical Reflection Grating Spectrometers (RGS) behind of its three nested sets Wolter I type mirrors. instrument allows high-resolution ( to 500) measurements in the soft range (6 38 Åor 2.1 0.3 keV) with a maximum effective area about 140 cm2 at 15 Å. Its design is optimized for detection K-shell transitions carbon, nitrogen, oxygen, neon, magnesium, and silicon, as well L shell iron. present paper gives full description RGS...
Ultraluminous infrared galaxies (ULIRGs) are outstanding due to their huge luminosity output in the infrared, which is predominantly powered by super starbursts and/or hidden active galactic nuclei (AGN). NGC 6240 one of nearest ULIRGs and considered a key representative its class. Here, we report first high-resolution imaging spectroscopy X-rays. The observation, performed with ACIS-S detector aboard Chandra X-ray observatory, led discovery two hard nuclei, coincident optical-IR 6240. AGN...
We present detailed spatially-resolved spectroscopy results of the observation Abell 1835 using European Photon Imaging Cameras (EPIC) and Reflection Grating Spectrometers (RGS) on XMM-Newton observatory. is a luminous (1046 ergs ), medium redshift (), X-ray emitting cluster galaxies. The observations support interpretation that large amounts cool gas are in multi-phase surrounded by hot ( keV) outer envelope. detect O VIII Lyα two Fe XXIV complexes RGS spectrum. emission measure below keV...
We use Chandra data to map the gas temperature in central region of merging cluster A2142. The is markedly nonisothermal; it appears that cooling flow has been disturbed but not destroyed by a merger. X-ray image exhibits two sharp, bow-shaped, shock-like surface brightness edges or density discontinuities. However, and pressure profiles across these indicate are shock fronts. reasonably continuous edges, while entropy jumps opposite sense (i.e. denser side edge lower temperature, hence...
We present high-resolution X-ray spectra of 14 putative cooling-flow clusters galaxies obtained with the Reflection Grating Spectrometer on XMM-Newton. The in sample span a large range temperatures and mass deposition rates. Various these exhibit line emission from O VIII, Ne X, Mg XII XI, Al XIII XII, Si XIV XIII, N VII, C VI as well all Fe L ions. strong cool plasma at just below ambient temperature, T0, down to T0/2, but also severe deficit relative predictions isobaric model lower...
Supermassive black holes in the nuclei of active galaxies expel large amounts matter through powerful winds ionized gas. The archetypal galaxy NGC 5548 has been studied for decades, and high-resolution X-ray UV observations have previously shown a persistent outflow. An observing campaign 2013 with six space observatories shows nucleus to be obscured by long-lasting, clumpy stream gas never seen before. It blocks 90% soft emission causes simultaneous deep, broad absorption troughs. outflow...
The X-ray Integral Field Unit (X-IFU) is the high resolution spectrometer of ESA Athena observatory. Over a field view 5' equivalent diameter, it will deliver spectra from 0.2 to 12 keV with spectral 2.5 eV up 7 on ∼ 5" pixels. X-IFU based large format array super-conducting molybdenum-gold Transition Edge Sensors cooled at 90 mK, each coupled an absorber made gold and bismuth pitch 249 μm. A cryogenic anti-coincidence detector located underneath prime TES enables non background be reduced....
The initial results from XMM-Newton observations of the rich cluster galaxies Abell 1795 are presented. spatially-resolved X-ray spectra taken by European Photon Imaging Cameras (EPIC) show a temperature drop at radius $\sim 200$ kpc center, indicating that ICM is cooling. Both EPIC and Reflection Grating Spectrometers (RGS) extracted center can be described an isothermal model with 4$ keV. volume emission measure any cool component ($<1$ keV) less than few % hot center. A strong OVIII...
We present the first high-resolution, soft X-ray spectrum of prototypical Seyfert 2 galaxy, NGC 1068. This was obtained with XMM-Newton Reflection Grating Spectrometer (RGS). Emission lines from H-like and He-like low-Z ions (from C to Si) Fe L-shell dominate spectrum. Strong, narrow radiative recombination continua (RRCs) for several are also present, implying that most observed emission arises in low-temperature plasma (kTe ~ a few eV). is photoionized by inferred nuclear continuum...
We present spatially resolved X-ray spectra taken with the EPIC cameras of XMM-Newton a sample 17 cooling clusters and three non-cooling for comparison. The deprojected are analyzed multi-temperature model, independent any priori assumptions about physics behind heating mechanisms. All show central decrement average temperature, most them factor . Three (Sérsic 159-3, MKW 3s Hydra A) only weak temperature decrement, while two others (A 399 A 2052) have very strong decrement. pressure...
Recent intensive Swift monitoring of the Seyfert 1 galaxy NGC 5548 yielded 282 usable epochs over 125 days across six UV/optical bands and X-rays. This is densest extended AGN continuum sampling ever obtained, with a mean rate <0.5 day. Approximately daily HST UV was also obtained. The light curves show strong correlations (r_max = 0.57 - 0.90) clearest measurement to date interband lags. These lags are well-fit by \tau propto \lambda^4/3 wavelength dependence, normalization that indicates...
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by Institute Space and Astronautical Science (ISAS). will investigate physics high-energy universe performing high-resolution, high-throughput spectroscopy with moderate angular resolution. covers very wide energy range from 0.3 keV to 600 keV. allows combination band (5-80 keV) provided multilayer coating, focusing hard mirrors imaging detectors, high energy-resolution soft (0.3-12...
About half of the baryons in local Universe are invisible and - according to simulations their dominant fraction resides filaments connecting clusters galaxies form low density gas with temperatures range 10^5
An extensive multi-satellite campaign on NGC 5548 has revealed this archetypal Seyfert-1 galaxy to be in an exceptional state of persistent heavy absorption. Our observations taken 2013-2014 with XMM-Newton, Swift, NuSTAR, INTEGRAL, Chandra, HST and two ground-based observatories have together enabled us establish that unexpected phenomenon is caused by outflowing stream weakly ionised gas (called the obscurer), extending from vicinity accretion disk broad-line region. In work we present...
ABSTRACT We present ground-based optical photometric monitoring data for NGC 5548, part of an extended multiwavelength reverberation mapping campaign. The light curves have nearly daily cadence from 2014 January to July in nine filters ( BVRI and ugriz ). Combined with ultraviolet the Hubble Space Telescope Swift , we confirm significant time delays between continuum bands as a function wavelength, extending wavelength coverage 1158 Å z band (~9160 Å). find that lags at wavelengths longer...
Abstract Swift intensive accretion disk reverberation mapping of four AGN yielded light curves sampled ∼200–350 times in 0.3–10 keV X-ray and six UV/optical bands. Uniform reduction cross-correlation analysis these data sets yields three main results: (1) The X-ray/UV correlations are much weaker than those within the UV/optical, posing severe problems for lamp-post reprocessing model which variations a central corona drive power surrounding disk. (2) interband lags generally consistent with...
We describe the first results from a six-month long reverberation-mapping experiment in ultraviolet based on 170 observations of Seyfert 1 galaxy NGC 5548 with Cosmic Origins Spectrograph Hubble Space Telescope. Significant correlated variability is found continuum and broad emission lines, amplitudes ranging ~30% to factor two lines three continuum. The variations all strong lag behind those continuum, He II 1640 lagging by ~2.5 days Lyman alpha 1215, C IV 1550, Si 1400 ~5-6 days....
This work presents a new plasma cooling curve that is calculated using the SPEX package. We compare our rates to those in previous works, and implement function grid-adaptive framework "AMRVAC". Contributions rate by individual elements are given, allow for creation of curves tailored specific abundance requirements. In some situations, it important be able include radiative losses hydrodynamics. The enhanced compression ratio can trigger instabilities (such as Vishniac thin-shell...
We present the analysis of XMM-Newton and Swift optical-UV X-ray observations Seyfert-1/QSO Mrk 509, part an unprecedented multi-wavelength campaign, investigating nuclear environment this AGN. The data are from a series 10 about 60 ks each, spaced each other by 4 days, taken in Oct-Nov 2009. During our 509 was also observed with for period 100 monitoring behaviour source before after observations. With these we have established continuum spectrum bands investigated its variability on...
(Abridged) The simultaneous UV to X-rays/gamma rays data obtained during the multi-wavelength XMM/INTEGRAL campaign on Seyfert 1 Mrk 509 are used in this paper and tested against physically motivated broad band models. Each observation has been fitted with a realistic thermal comptonisation model for continuum emission. Prompted by correlation between soft X-ray flux, we use component excess. X-rays/gamma-rays emission of can be well these components. presence relatively hard high-energy...