Search Publications
ACS imaging of star clusters in M 51. II. The luminosity function and mass function across the disk
Larsen, S. S.; Gieles, M.; Lamers, H. J. G. L. M. +2 more
Context: Whether or not there exists a physical upper mass limit for star clusters is as yet unclear. For small cluster samples the mass function may not be sampled all the way to the truncation, if there is one. Data for the rich cluster population in the interacting galaxy M 51 enables us to investigate this in more detail.
Aims: Using HST/A…
Observational evidence for return currents in solar flare loops
Benz, A. O.; Battaglia, M.
Context: The common flare scenario comprises an acceleration site in the corona and particle transport to the chromosphere. Using satellites available to date it has become possible to distinguish between the two processes of acceleration and transport, and study the particle propagation in flare loops in detail, as well as complete comparisons wi…
The physical structure of the point-symmetric and quadrupolar planetary nebula NGC 6309
Torrelles, J. M.; Miranda, L. F.; Vázquez, R. +4 more
Aims:We analyse the point-symmetric planetary nebula
Methods: We used VLA-D λ3.6-cm continuum, ground-based, and HST-archive imaging as well as long slit high-…
INTEGRAL and Swift/XRT observations of the SFXT IGR J16479-4514: from quiescence to fast flaring activity
Masetti, N.; Bird, A. J.; Ubertini, P. +6 more
Context: The fast X-ray transient IGR J16479-4514 is known to display flares typically lasting a few hours. Recently, its counterpart has been identified with a supergiant star, therefore the source can be classified as a member of the newly discovered class of Supergiant Fast X-ray Transients (SFXTs); specifically, it is the one with the highest …
Abundance variations and first ionization potential trends during large stellar flares
Nordon, R.; Behar, E.
Context: In the solar corona, elements of low first ionization potential (FIP ⪉ 10 eV) are enriched relative to their abundances in the photosphere, while high-FIP abundances remain unchanged. This was labeled as the Solar FIP effect. High-resolution X-ray spectroscopy has revealed that active stellar coronae show an opposite effect, which was lab…
The properties of penumbral microjets inclination
Katsukawa, Y.; Jurčák, J.
Aims: We investigate the dependence of penumbral microjets inclination on the position within penumbra.
Methods: The high cadence observations taken on 10 November 2006 with the Hinode satellite through the Ca II H and G-band filters were analysed to determine the inclination of penumbral microjets. The results were then compared with the incl…
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…