A5076292184- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Surface Roughness and Optical Measurements
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Atomic and Molecular Physics
- Solar and Space Plasma Dynamics
- Advanced Chemical Physics Studies
- Advanced Measurement and Metrology Techniques
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Optical Coatings and Gratings
- Fluid Dynamics and Turbulent Flows
- Astrophysics and Cosmic Phenomena
- Optical measurement and interference techniques
- Particle Dynamics in Fluid Flows
- Aeolian processes and effects
- Adhesion, Friction, and Surface Interactions
- Particle physics theoretical and experimental studies
- Advanced Fiber Optic Sensors
- Particle Detector Development and Performance
- Cultural Heritage Materials Analysis
- Astronomical Observations and Instrumentation
KTH Royal Institute of Technology
2015-2024
Stockholm University
2015-2024
Nordic Institute for Theoretical Physics
2016-2023
University of Copenhagen
2010-2015
Uppsala University
1989-2012
Eötvös Loránd University
1998
Sandia National Laboratories
1998
Linköping University
1989-1997
Universidade Federal do Rio de Janeiro
1994
University of Wuppertal
1993
Valence electron spectra of the methyl halides and alcohol have been induced by means HeI resonance radiation at 21.22 eV. A large number new vibrational bands are reported. The observation these was facilitated a high instrumental resolving power fast data acquisition. In most cases observed in 1 → 2 E transitions but also band transition CH 3 I exhibits extensive progressions closely spaced not previously structure is affected vibronic coupling. e Cl probably reflects operation Ham effect....
We study metal depletion due to dust in the interstellar medium (ISM) infer properties of grains and characterize content galaxies, down low metallicity intermediate redshift z. provide column densities abundances a sample 70 damped Lyman-α absorbers (DLAs) towards quasars, observed at high spectral resolution with Very Large Telescope (VLT) Ultraviolet Visual Echelle Spectrograph (UVES). This is largest phosphorus measured DLAs so far. use literature measurements for Galactic clouds cover...
Recent epidemiological studies have indicated high risk factors for persons exposed to vibrations. We measured the in vivo responses of lumbar vertebrae and sacrum five volunteers who were subjected pure sinusoidal vertical vibrations seated position. Two acceleration amplitudes used, one three meters per second squared, with frequencies ranging from two fifteen hertz. Spinal vibration was using a transducer that attached directly spinous processes. Axial, horizontal, rotatory accelerations...
HeI induced valence electron spectra of benzene and the hexafluorides sulphur, molybdenum, tungsten uranium are presented together with a HeII spectrum sulphur hexafluoride. Vibrational band structure has been resolved in all molecules energies these bands reported. A description is also given multichannel detector system which facilitated recordings spectra.
Isotopic shift data for Hei induced high resolution valence electron spectra of H2 16O, 18O, and D2 16O are presented. From the differences in vibrational subspectra we were able to deduce adiabatic ionization energies geometries ions assign excited vibrations normal modes. The ν2 progression 2A1 band was found be affected by strong vibronic coupling.
Optical coherence tomography (OCT) is a promising tool for detecting micro channels, metal prints, defects and delaminations embedded in alumina zirconia ceramic layers at hundreds of micrometers beneath surfaces. The effect surface roughness scattering probing radiation within sample on OCT inspection analyzed from the experimental simulated images samples with varying roughnesses operating wavelengths. By Monte Carlo simulations mid-IR optimal wavelength found to be 4 µm 2 achieving...
We suggest a new way of determining abundances and electron temperatures in H ii regions from strong emission lines. Our approach is based on the standard assumption that with similar intensities lines have physical properties abundances. A 'counterpart' for studied region may be chosen among well-measured (reference regions) by comparison carefully combinations strong-line intensities. Then investigated can assumed to same as those its counterpart. In other words, we determine 'by...
<i>Context. <i/>Knowing how the mass loss of carbon-rich AGB stars depends on stellar parameters is crucial for evolution modelling, as well understanding when and circumstellar structures emerge around these stars, e.g., dust shells so-called detached expelled gas.<i>Aims. <i/>The purpose this paper to explore parameter space using a numerical radiation hydrodynamic (RHD) model carbon-star atmospheres, including detailed description formation frequency-dependent radiative transfer, in order...
In this paper we consider the implications of distributions dust and metals in disc M31. We derive mean radial using a map created from Herschel images M31 sampling entire far-infrared (FIR) peak. Modified blackbodies are fit to approximately 4000 pixels with varying, as well fixed, emissivity index (beta). An overall metal distribution is also derived data collected literature. use simple analytical model evolution galaxy contributed by stellar sources interstellar grain growth,...
The high resolution HeI induced electron spectrum of H 2 S is presented and the energies observed vibrational vibronic bands are reported. In B 1 band two progressions have been measured. A structure associated with v bending vibrations has partially resolved. Assignments suggested from a comparison electronic emission data in terms angular momentum quantum numbers K .
Recent works have demonstrated a surprisingly small variation of the dust-to-metals ratio in different environments and correlation between dust extinction density stars. Naively, one would interpret these findings as strong evidence cosmic being produced mainly by But other observational suggest there is significant with metallicity. As we demonstrate this paper, simple star-dust scenario problematic also sense that it requires destruction interstellar medium (e.g., due to passage supernova...
We use simple analytical models of the build up dust component and compare these with radial distributions derived from observations SINGS galaxies. The show that gradients are indeed typically steeper than corresponding metallicity our indicate very little destruction, but significant growth in ISM for most Hence, we conclude there is evidence non-stellar production, destruction due to SNe shock waves. find reprocessed rather destroyed by shocks SNe. Finally, argue abundances using standard...
We suggest a procedure for estimating Nth degree polynomial approximations to unknown (or known) probability density functions (PDFs) based on N statistical moments from each distribution. The is the method of and setup algorithmically aid applicability ensure rigor in use. In order show applicability, PDF are obtained distribution families Normal, Log-Normal, Weibull as well bimodal data set anonymized household electricity results compared with traditional series expansion methods...
Context. The origin of the so called "detached shells" around AGB stars is not fully understood, but two common hypotheses state that these shells form either through interaction distinct wind phases or an eruptive mass loss associated with a He-shell flash. We present model formation detached thermal pulse asymptotic giant branch (TP-AGB) stars, based on detailed modelling and stellar evolution, leading to combination interaction.
We argue that the energy injection of pulsations may be greater importance to mass-loss rate AGB stars than metallicity, and trend with metallicity is not as simple sometimes assumed. Using our detailed radiation hydrodynamical models include dust formation, we illustrate effects pulsation on wind properties. find scales kinetic input by long a dust-saturated does occur, all other stellar parameters are kept constant. This includes absolute abundance condensible carbon (not bound in CO),...
We suggest an empirical calibration for the determination of oxygen and nitrogen abundances electron temperature in H ii regions which [O ii]λ3727+λ3729 line (R2) is not available. The based on strong emission lines O++, N+ S+ (NS calibration) derived using spectra with measured temperatures as data points. NS makes it possible to derive nearby galaxies from Sloan Digital Sky Survey (SDSS) R2 out wavelength range, but can also be used abundance determinations any region independently whether...
Multi-zone chemical evolution models (CEMs), differing in the nucleosynthesis prescriptions (yields) and of star formation, have been computed for Milky Way. All fit observed O/H Fe/H gradients well reproduce main characteristics gas distribution, but they are also designed to do so. For C/H gradient results inconclusive with regards yields formation. The C/Fe O/Fe vs. Fe/H, as C/O trends predicted by solar neighbourhood zone were compared stellar abundances from literature. all data, O/H,...
He I induced valence electron spectra are presented from CF 3 Cl, 2 Cl and CFCl . A high resolution spectrometer with a computerized multichannel detector system is used for detailed data recordings. Several new electronic vibrational bands reported.