Search Publications
An intense state of hard X-ray emission of Cyg X-1 observed by INTEGRAL coincident with TeV measurements
Malzac, J.; Laurent, P.; Cadolle Bel, M. +3 more
Aims: We present INTEGRAL light curves and spectra of the black-hole binary Cyg X-1 during a bright event that occurred in 2006 September, and which was simultaneous with a detection at 0.15-1 TeV energies by the MAGIC telescope.
Methods: We analyse the hard X-ray emission from 18 to 700 keV with the INTEGRAL data taken on 2006 September 24-26…
An intriguing solar microflare observed with RHESSI, Hinode, and TRACE
Krucker, S.; Lin, R. P.; Hannah, I. G. +2 more
Aims:We investigate particle acceleration and heating in a solar microflare.
Methods: In a microflare with non-thermal emission to remarkably high energies (>50 keV), we investigate the hard X-rays with RHESSI imaging and spectroscopy and the resulting thermal emission seen in soft X-rays with Hinode/XRT and in EUV with TRACE.
Results: …
Integral-field spectroscopy of a Lyman-break galaxy at z = 3.2: evidence for merging
Verma, A.; Davies, R. I.; Eisenhauer, F. +2 more
We present spatially-resolved, rest-frame optical spectroscopy of a z∼ 3 Lyman-break galaxy (LBG), Q0347-383 C5, obtained with SINFONI on the VLT. This galaxy, among the ∼ 10% brightest LBGs, is only the second z∼ 3 LBG observed with an integral-field spectrograph. It was first described by Pettini et al. (2001, ApJ, 554, 981), who obtained WFPC2 …
Swift follow-up observations of INTEGRAL sources of unknown nature
Chaty, S.; Tomsick, J. A.; Rodriguez, J.
Context: Since its launch in 2002, INTEGRAL has discovered many new hard X-ray sources. A lot of them still lack sufficient positional accuracy, for finding counterparts at other wavelengths. Their true nature is, therefore, still unknown.
Aims: The goal of this study is to give an accurate X-ray position for 12 of these sources so as to furth…
Molecular hydrogen in the circumstellar environments of Herbig Ae/Be stars probed by FUSE
Deleuil, M.; Bouret, J. -C.; Roberge, A. +7 more
Context: Molecular hydrogen (H2) gas is the most abundant molecule in the circumstellar (CS) environments of young stars. It is thus a key element in our understanding of the evolution of pre-main sequence stars and their environments towards the main sequence.
Aims: At the present time, little is known about the gas as compared to the dust in…
Diffuse stellar emission in X-ray luminous galaxy clusters at z ~ 0.3. I. Is the diffuse optical light boosted and rejuvenated in merging clusters?
Zhang, Y. -Y.; Finoguenov, A.; Böhringer, H. +4 more
Context: Clusters of galaxies host a diffuse population of intergalactic stars. Diffuse optical light is observed in clusters up to redshift z ∼ 0.4. Recent cosmological hydrodynamical simulations show that this intracluster light originates nearly in parallel with the build-up of the brightest cluster galaxy (BCG), as identified at z=0. However, …
Physical parameters along the boundaries of a mid-latitude streamer and in its adjacent regions
Susino, R.; Landi, E.; Spadaro, D. +2 more
Context: Coronal streamers appear to be strictly associated with the generation of the slow solar wind, even if a firm identification of the sources of the particle flux within these structures is still an unresolved issue.
Aims: The purpose of this work is to contribute to a better knowledge of the physical characteristics of streamers and of…
Net circular polarization of sunspots in high spatial resolution
Kubo, M.; Lites, B. W.; Ichimoto, K. +8 more
Context: Net circular polarization (NCP) of spectral lines in sunspots has been most successfully explained by the presense of discontinuities in the magnetic field inclination and flow velocity along the line-of-sight in the geometry of the embedded flux tube model of penumbrae (Δγ-effect).
Aims: The fine scale structure of NCP in a sunspot i…
The host of GRB 060206: kinematics of a distant galaxy
Vreeswijk, P. M.; Wijers, R. A. M. J.; Rol, E. +13 more
Context: GRB afterglow spectra are sensitive probes of interstellar matter along the line-of-sight in their host galaxies, as well as in intervening galaxies. The rapid fading of GRBs makes it very difficult to obtain spectra of sufficient resolution and S/N to allow for these kinds of studies.
Aims: We investigate the state and properties of …
Variability-selected active galactic nuclei from supernova search in the Chandra deep field south
Boutsia, K.; Cappellaro, E.; Puccetti, S. +2 more
Context: Variability is a property shared by virtually all active galactic nuclei (AGNs), and was adopted as a criterion for their selection using data from multi epoch surveys. Low Luminosity AGNs (LLAGNs) are contaminated by the light of their host galaxies, and cannot therefore be detected by the usual colour techniques. For this reason, their …