Search Publications
Spectral and intensity variations of Galactic 26Al emission
Wang, W.; Strong, A. W.; Knödlseder, J. +9 more
Aims: Gamma-ray line emission from the radioactive decay of 26Al reflects nucleosynthesis in massive stars and supernovae. We use INTEGRAL 26Al measurements to characterize the distribution and characteristics of 26Al source regions throughout the Galaxy.
Methods: The spectrometer SPI aboard INTEGRAL has accumu…
The large-scale shock in the cluster of galaxies Hydra A
Finoguenov, A.; Böhringer, H.; Simionescu, A. +5 more
We analyzed a deep XMM-Newton observation of the cluster of galaxies Hydra A, focusing on the large-scale shock discovered in Chandra images as a discontinuity in the surface brightness. The shock front can be seen both in the pressure map and in temperature profiles in several sectors. We compared the results of a spherically symmetric hydrodynam…
The Quintuplet cluster. I. A K-band spectral catalog of stellar sources
Hamann, W. -R.; Oskinova, L. M.; Liermann, A.
Context: Three very massive clusters are known to reside in the Galactic center region, the Arches cluster, the Quintuplet cluster, and the central parsec cluster, each of them rich in young hot stars. With new infrared instruments, this region is no longer obscured for the observer.
Aims: For understanding these very massive clusters, it is e…
HST/STIS observations of the RW Aurigae bipolar jet: mapping the physical parameters close to the source
Ray, T. P.; Eislöffel, J.; Bacciotti, F. +2 more
Context: We present the results of new spectral diagnostic investigations applied to high-resolution long-slit spectra obtained with the Hubble Space Telescope Imaging Spectrograph (HST/STIS) of the jet from the T Tauri star RW Aur.
Aims: Our primary goal is to determine basic physical parameters (electron density ne and electron te…
Multi-wavelength observations and modelling of a canonical solar flare
Klimchuk, J. A.; Gallagher, P. T.; Milligan, R. O. +1 more
Aims: We investigate the temporal evolution of temperature, emission measure, energy loss, and velocity in a C-class solar flare from both observational and theoretical perspectives.
Methods: The properties of the flare were derived by following the systematic cooling of the plasma through the response functions of a number of instruments - th…
High-energy characteristics of the schizophrenic pulsar PSR J1846-0258 in Kes 75. Multi-year RXTE and INTEGRAL observations crossing the magnetar-like outburst
Kuiper, L.; Hermsen, W.
Aims: PSR J1846-0258 is a young rotation-powered pulsar with one of the highest surface magnetic field strengths, located in the centre of SN-remnant Kes-75. In June 2006 a magnetar-like outburst took place. Using multi-year RXTE and INTEGRAL observations covering the epoch of the outburst, we aim to study the temporal and spectral characteristics…
The X-ray view of giga-hertz peaked spectrum radio galaxies
Guainazzi, M.; Piconcelli, E.; Grandi, P. +5 more
Context: This paper presents the X-ray properties of a flux- and volume-limited complete sample of 16 giga-hertz peaked spectrum (GPS) galaxies.
Aims: This study addresses three basic questions in our understanding of the nature and evolution of GPS sources: a) What is the physical origin of the X-ray emission in GPS galaxies? b) Which physica…
The velocity field of sunspot penumbrae. I. A global view
Franz, M.; Schlichenmaier, R.
Aims. We investigated the vertical penumbral plasma flow on small spatial scales using data recorded by the spectropolarimeter of the solar optical telescope onboard Hinode.
Methods: We computed maps of apparent Doppler velocities by comparing the spectral positions of the Fe I 630.15 nm & Fe I 630.25 nm lines with the averaged line profil…
Properties of WNh stars in the Small Magellanic Cloud: evidence for homogeneous evolution
Martins, F.; Hillier, D. J.; Foellmi, C. +4 more
Aims: We aim to assess the nature of three WNh stars in the SMC, to constrain stellar evolution beyond the main sequence at low metallicity, and to investigate the metallicity dependence of the clumping properties of massive stars.
Methods: We compute atmosphere models to derive the stellar and wind properties of the three WNh targets. A FUV/U…
Keck spectroscopic survey of strongly lensed galaxies in Abell 1703: further evidence of a relaxed, unimodal cluster
Jullo, E.; Richard, J.; Kneib, J. P. +2 more
Context: Strong gravitational lensing is a unique tool that can be used to accurately model the inner mass distribution of massive galaxy clusters. In particular, clusters with large Einstein radii provide a wealth of multiply imaged systems in the cluster core. Measuring the redshift of these multiple images provides strong constraints for precis…