Search Publications
XMMSL1 J060636.2-694933: an XMM-Newton slew discovery and Swift/Magellan follow up of a new classical nova in the LMC
Read, A. M.; Esquej, P.; Freyberg, M. J. +7 more
Aims: In order to discover new X-ray transients, the data taken by XMM-Newton as it slews between targets are being processed and cross-correlated with other X-ray observations.
Methods: A bright source, XMMSL1 J060636.2-694933, was detected on 18 July 2006 at a position where no previous X-ray source had been seen. The XMM-Newton slew data, p…
A new spectroscopic and interferometric study of the young stellar object V645 Cygni
Weigelt, G.; Hofmann, K. -H.; Schertl, D. +14 more
Aims: We present the results of high-resolution optical spectroscopy, low-resolution near-IR spectroscopy and near-infrared speckle interferometry of the massive young stellar object candidate V645 Cyg, acquired to refine its fundamental parameters and the properties of its circumstellar envelope.
Methods: Speckle interferometry in the H- and …
Spectroscopic binaries among Hipparcos M giants. II. Binary frequency
Jorissen, A.; Udry, S.; Famaey, B. +3 more
Context: This paper is the second in a series devoted to studying the properties of binaries with M giant primaries.
Aims: The binary frequency of field M giants is derived and compared with the binary fraction of K giants.
Methods: Diagrams of the CORAVEL spectroscopic parameter Sb (measuring the average line width) vs. radial-velocity st…
Relationship between the topological skeleton, current concentrations, and 3D magnetic reconnection sites in the solar atmosphere
Priest, E. R.; Maclean, R. C.; Büchner, J.
Aims: The aim of this work is to determine the relationship between the 3D structure of the coronal magnetic field, diagnosed by the topological skeleton, and current concentrations as potential sites of 3D reconnection.
Methods: We utilised the results of 3D numerical MHD simulations of an observed EUV bright point (BP) in the solar atmospher…
Magnetic helicity and active filament configuration
Poedts, S.; Romano, P.; Zuccarello, F. P. +2 more
Context: The role of magnetic helicity in active filament formation and destabilization is still under debate.
Aims: Although active filaments usually show a sigmoid shape and a twisted configuration before and during their eruption, it is unclear which mechanism leads to these topologies. In order to provide an observational contribution to c…
HST observations of the nebula around the central compact object in the Vela Jr. supernova remnant
de Luca, A.; Pellizzoni, A.; Mignani, R. P.
Context: A handful of young (a few thousand years) supernova remnants (SNRs) host point-like X-ray sources, dubbed central compact objects (CCOs), which are thought to be radio-silent isolated neutron stars formed by the supernova explosion. So far, no CCO has been firmly detected at other wavelengths. However, ground-based observation in the Hα b…
VLT optical observations of the isolated neutron star RX J0420.0-5022
Haberl, F.; Motch, C.; Mignani, R. P. +3 more
Context: X-ray observations performed with the Röntgen Satellite (ROSAT) led to the discovery of seven radio-silent isolated neutron stars (INSs) which are detected only through the relatively dim and purely thermal X-ray emission from the cooling star surface. A few of these INSs (X-ray Dim INSs, or XDINSs) have been also detected at optical wave…
Electron density in the quiet solar coronal transition region from SoHO/SUMER measurements of S VI line radiance and opacity
Vial, J. -C.; Buchlin, E.
Context: The steep temperature and density gradients that are measured in the coronal transition region challenge the model interpretation of observations.
Aims: We derive the average electron density < ne > in the region emitting the S vi lines. We use two different techniques, which allow us to derive linearly-weighted (opac…
Transit detections of extrasolar planets around main-sequence stars. I. Sky maps for hot Jupiters
Mislis, D.; Heller, R.; Antoniadis, J.
Context: The findings of more than 350 extrasolar planets, most of them nontransiting Hot Jupiters, have revealed correlations between the metallicity of the main-sequence (MS) host stars and planetary incidence. This connection can be used to calculate the planet formation probability around other stars, not yet known to have planetary companions…
Markov properties of solar granulation
Asensio Ramos, A.
Aims: We estimate the minimum length on which solar granulation can be considered to be a Markovian process.
Methods: We measure the variation in the bright difference between two pixels in images of the solar granulation for different distances between the pixels. This scale-dependent data is empirically analyzed to find the minimum scale on …