Search Publications
Measuring supermassive black holes with gas kinematics. II. The LINERs IC 989 , NGC 5077 , and NGC 6500
Marconi, A.; Capetti, A.; de Francesco, G.
We present results from a kinematical study of the gas in the nucleus of a sample of three LINER galaxies, obtained from archival HST/STIS long-slit spectra. We found that, while for the elliptical galaxy NGC 5077, the observed velocity curves are consistent with gas in regular rotation around the galaxy's center, this is not the case for the two …
Solar coronal rotation determined by X-ray bright points in Hinode/XRT and Yohkoh/SXT full-disc images
Kariyappa, R.
Aims: Our aim is to identify and trace the X-ray bright points (XBPs) over the disc and use them as tracers to determine the coronal rotation. This investigation will help to clarify and understand several issues: (i) whether the corona rotates differentially; (ii) whether the rotation depends on the sizes of the XBPs; and (iii) whether there is a…
Coronal loop oscillations and diagnostics with Hinode/EIS
Taroyan, Y.; Bradshaw, S.
Context: Standing slow (acoustic) waves commonly observed in hot coronal loops offer a unique opportunity to understand the properties of the coronal plasma. The lack of evidence for similar oscillations in cooler loops is still a puzzle.
Aims: The high cadence EIS instrument on board recently launched Hinode has the capability to detect wave …
Cosmological models in scalar tensor theories of gravity and observations: a class of general solutions
Piedipalumbo, E.; Demianski, M.; Rubano, C. +1 more
Aims: We study cosmological models in scalar tensor theories of gravity with power-law potentials as models of an accelerating universe.
Methods: We consider cosmological models in scalar tensor theories of gravity that describe an accelerating universe and study a family of inverse power-law potentials, for which exact solutions of the Einste…
Asteroid 2867 Steins. II. Multi-telescope visible observations, shape reconstruction, and rotational state
Jorda, L.; Lamy, P. L.; Colas, F. +14 more
Context: Asteroid 2867 Steins is the first target of the Rosetta space mission with a flyby scheduled in September 2008.
Aims: An early physical characterization is needed to optimize the flyby parameters and the science operations, and to maximize the scientific return. The aim of this article is to characterize the shape and rotational state…
Non-thermal bremsstrahlung from supernova remnants and the effect of Coulomb losses
Vink, Jacco
Aims: We investigate the shape of the electron cosmic ray spectrum in the range up to ~1000 keV, assuming that the acceleration process at the shock results in a power law in momentum, and that downstream of the shock the spectrum is affected by Coulomb interactions with background electrons only.
Methods: In the non-relativistic regime one ca…
On the morphology of sigma-drop galaxies
Knapen, J. H.; Comerón, S.; Beckman, J. E.
Context: Local reductions of the stellar velocity dispersion in the central regions of galaxies are known as sigma-drops (σ-drops). Knowing the origin of these features can lead to better understanding of inner galactic dynamics.
Aims: We present a sample of 20 σ-drop galaxies matched with a control sample of galaxies without σ-drop in order t…
Environmental effects on the globular cluster blue straggler population: a statistical approach
Moretti, A.; Piotto, G.; de Angeli, F.
Context: Blue stragglers stars (BSS) constitute an ubiquitous population of objects whose origin involves both dynamical and stellar evolution.
Aims: In this paper we study the properties of a catalogue of BSS extracted from an homogeneous sample of 56 Galactic globular clusters (GC) observed with Wide-Field Planetary Camera 2 on board of Hubb…
High resolution radio study of the pulsar wind nebula within the supernova remnant G0.9+0.1
Decourchelle, A.; Giacani, E.; Dubner, G.
Aims: We have conducted a study in radio wavelengths and in X-rays of the pulsar wind nebula (PWN) in the supernova remnant (SNR) G0.9+0.1 with the goal of investigating in detail its morphology and to accurately determine its characteristic parameters.
Methods: To carry out this research we have observed the PWN at λ3.6 and 6 cm using the Aus…
High resolution spectroscopy of the inner ring of SN 1987A
Sollerman, J.; Lundqvist, P.; Spyromilio, J. +8 more
We discuss high resolution VLT/UVES observations (FWHM ~ 6 km s-1) from October 2002 (day ~5700 past explosion) of the shock interaction of SN 1987A and its circumstellar ring. A large number of narrow emission lines from the unshocked ring, with ion stages from neutral up to Ne V and Fe VII, have been identified. A nebular analysis of …