Search Publications
Long term hard X-ray variability of the anomalous X-ray pulsar 1RXS J170849.0-400910 discovered with INTEGRAL
Tiengo, A.; Götz, D.; Mereghetti, S. +6 more
Aims:We report on a multi-band high-energy observing campaign aimed at studying the long term spectral variability of the Anomalous X-ray Pulsar (AXP) 1RXS J170849.0-400910, one of the magnetar candidates.
Methods: We observed 1RXS J170849.0-400910 in Fall 2006 and Spring 2007 simultaneously with Swift/XRT, in the 0.1-10 keV energy range, and …
Coronal abundances of X-ray bright pre-main sequence stars in the Taurus molecular cloud
Güdel, M.; Micela, G.; Maggio, A. +2 more
Aims:We studied the thermal properties and chemical composition of the X-ray emitting plasma of a sample of bright members of the Taurus Molecular Cloud to investigate possible differences among classical and weak-lined T Tauri stars, and possible dependences of the abundances on the stellar activity level and/or on the presence of accretion/circu…
Outflow or galactic wind: the fate of ionized gas in the halos of dwarf galaxies
Weis, K.; Bomans, D. J.; Dettmar, R. -J. +1 more
Context: Hα images of star bursting irregular galaxies reveal a large amount of extended ionized gas structures, in some cases at kpc-distance away from any place of current star forming activity. A kinematic analysis of especially the faint structures in the halo of dwarf galaxies allows insights into the properties and the origin of this gas com…
Possible non-thermal nature of the soft-excess emission in the cluster of galaxies Sérsic 159-03
Kaastra, J. S.; Vink, J.; Tamura, T. +3 more
We present an analysis of new Suzaku data and archival data from XMM-Newton of the cluster of galaxies Sérsic 159-03, which has a strong soft X-ray excess emission component. The Suzaku observation confirms the presence of the soft excess emission, but it does not confirm the presence of redshifted O VII lines in the cluster. Radial profiles and 2…
E-type asteroid (2867) Steins: flyby target for Rosetta
Barucci, M. A.; Fulchignoni, M.; Vernazza, P. +3 more
Aims:The mineralogy of the asteroid (2867) Steins was investigated in the framework of a ground-based science campaign dedicated to the future encounter with Rosetta spacecraft.
Methods: Near-infrared (NIR) spectra of the asteroid in the 0.8-2.5 µm spectral range have been obtained with SpeX/IRTF in remote-observing mode from Meudon, Fra…
On the dynamic nature of the prolate solar chromosphere: jet formation
Filippov, B.; Koutchmy, S.; Vilinga, J.
Context: In "cool" spectral lines, the smoothed upper edge of the solar chromosphere is prolate in the South-North direction at the epoch of minimum solar activity and nearly spherically symmetric at the maximum phase. We attribute the effect to the dynamical nature of the upper chromosphere, which consists of a large number of small jet-like stru…
XMM observation of 1RXS J180431.1-273932: a new M-type X-ray binary with a 494 s-pulse period neutron star?
Guainazzi, M.; Nucita, A. A.; Carpano, S.
Context: Low-mass X-ray binaries are peculiar binary systems composed of a compact object and a low-mass star. Recently, a new class of these systems, known as symbiotic X-ray binaries (with a neutron star with a M-type giant companion), has been discovered.
Aims: Here, we present long-duration XMM observations of the source 1RXS J180431.1-273…
An empirical 3D model of the large-scale coronal structure based on the distribution of Hα filaments on the solar disk
Habbal, S. R.; Morgan, H.
Context: Despite the wealth of solar data currently available, the explicit connection between coronal streamers and features on the solar disk remains unresolved.
Aims: To reproduce the large-scale coronal structure starting from the solar surface, an empirical three-dimensional (3D) model is used to test the assumption that such structure, n…
First detection of a minor merger at z ~ 0.6
Yang, Y.; Neichel, B.; Flores, H. +3 more
Context: Numerical simulations predict that minor mergers are an important channel for the mass assembly of galaxies. However, minor mergers are relatively difficult to detect using imaging, especially at high redshift. While such events are much less violent than major mergers, they can nevertheless leave several features on the kinematical struc…
The age structure of globular cluster systems in early-type galaxies and its dependence on host galaxy properties
Hilker, M.; Kissler-Patig, M.; Hempel, M. +1 more
Aims:We present the results of an optical - near-infrared photometric survey of globular cluster systems in early-type galaxies. Our project aims to study correlations between the age structure of the globular cluster systems and environmental as well as structural parameters of their host galaxies.
Methods: To derive the age structure in glob…