Search Publications
A large crater as a probe of the internal structure of the E-type asteroid Steins
Benz, W.; Jutzi, M.; Michel, P.
Context. The detection of a large crater (2 km in diameter) on Steins, a diamond-shape asteroid with a diameter of only about 4.6 km, was a large surprise given the size of the asteroid itself. Steins belongs to the rare class of E-type asteroids, which had not been observed by any spacecraft before the Rosetta mission of the European Space Agency…
The broad-band X-ray spectrum of the Seyfert 1 galaxy, MCG+8-11-11
de Rosa, A.; Bianchi, S.; Piconcelli, E. +5 more
Aims: Evidence is mounting that the main ingredients of the unification models of active galactic nuclei may behave differently from expectations, and be intimately related to fundamental physical parameters. The availability of high signal-to-noise broad-band X-ray spectra provides us with the opportunity to study in detail all the contribut…
Large and small-scale structures of the local Galactic disc. A maximum entropy approach to the stellar velocity distribution
Cubarsi, R.
An analytical model based on the maximum entropy approach is proposed to describe the eventual asymmetries of the velocity distribution, which are collected through its sample moments. If an extended set of moments is available, the current method provides a linear algorithm, associated with a Gramian system of equations, that leads to a fast and …
How are the EUV and radio polar limb-brightenings correlated?
Giménez de Castro, C. G.; Varela Saraiva, A. C.; Costa, J. E. R. +1 more
Aims: We correlate the polar limb brightening time evolution observed with pass-band filters centered at the EUV 17.1 nm (Fe ix,x) and 30.4 nm (He ii) lines with radio continuum images obtained at 17 GHz (~1.76 cm) during solar cycle 23.
Methods: We determine the limb brightening in units of the quiet Sun from daily maps at 17.1 and 30.4…
Cold dust clumps in dynamically hot gas
Poglitsch, A.; Bernard, J. -P.; Reach, W. T. +27 more
Aims: We present clumps of dust emission from Herschel observations of the Large Magellanic Cloud (LMC) and their physical and statistical properties. We catalog cloud features seen in the dust emission from Herschel observations of the LMC, the Magellanic type irregular galaxy closest to the Milky Way, and compare these features with H i cat…
Evidence of grain growth in the disk of the bipolar proto-planetary nebula M 1-92
Meixner, M.; Murakawa, K.; Ueta, T.
Aims: We investigate the dust grain size and dust shell structure of the bipolar proto-planetary nebula M 1-92.
Methods: We performed radiative transfer modeling of the dust shells of M 1-92. Our models consists of a disk and bipolar lobes that are surrounded by an AGB shell, each component having different dust characteristics. The mode…
Observations of solar scattering polarization at high spatial resolution
Lites, B. W.; Ichimoto, K.; Snik, F. +3 more
Context. The weak, turbulent magnetic fields that supposedly permeate most of the solar photosphere are difficult to observe, because the Zeeman effect is virtually blind to them. The Hanle effect, acting on the scattering polarization in suitable lines, can in principle be used as a diagnostic for these fields. However, the prediction that the ma…
Interstellar absorptions towards the LMC:. small-scale density variations in Milky Way disc gas
Wakker, B. P.; Nasoudi-Shoar, S.; de Boer, K. S. +1 more
Observations show that the interstellar medium (ISM) contains sub-structure on scales less than 1 pc, detected in the form of spatial and temporal variations in column densities or optical depth. Despite the number of detections, the nature and ubiquity of the small-scale structure in the ISM is not yet fully understood. We use UV absorption data …
The Herschel-SPIRE submillimetre spectrum of Mars
Thomas, N.; Hartogh, P.; Blommaert, J. +44 more
We have obtained the first continuous disk averaged spectrum of Mars from 450 to 1550 Ghz using the Herschel-SPIRE Fourier-transform spectrometer. The spectrum was obtained at a constant resolution of 1.4 GHz across the whole band. The flux from the planet is such that the instrument was operated in “bright source” mode to prevent saturation of th…
The distance to the C component of I Zw 18 and its star formation history. A probabilistic approach
Luridiana, V.; Cerviño, M.; Pérez, E. +2 more
Aims: We analyzed the resolved stellar population of the C component of the extremely metal-poor dwarf galaxy I Zw18 in order to evaluate its distance and star formation history as accurately as possible. In particular, we aimed at answering the question of whether this stellar population is young.
Methods: We developed a probabilistic a…