Search Publications
Unveiling the nature of INTEGRAL objects through optical spectroscopy. VII. Identification of 20 Galactic and extragalactic hard X-ray sources
Palazzi, E.; Minniti, D.; Masetti, N. +17 more
Within the framework of our program of assessment of the nature of unidentified or poorly known INTEGRAL sources, we present here spectroscopy of optical objects, selected through positional cross-correlation with soft X-ray detections (afforded with satellites such as Swift, ROSAT, Chandra and/or XMM-Newton) as putative counterparts of hard X-ray…
A possible architecture of the planetary system HR 8799
Krivov, A. V.; Löhne, T.; Neuhäuser, R. +4 more
HR 8799 is a nearby A-type star with a debris disk and three planetary candidates, which have been imaged directly. We undertake a coherent analysis of various observational data for all known components of the system, including the central star, imaged companions, and dust. Our goal is to elucidate the architecture and evolutionary status of the …
VLT-FLAMES analysis of 8 giants in the bulge metal-poor globular cluster NGC 6522: oldest cluster in the Galaxy?. Analysis of 8 giants in NGC 6522
Minniti, D.; Zoccali, M.; Bica, E. +5 more
Context: NGC 6522 has been the first metal-poor globular cluster identified in the bulge by Baade. Despite its importance, very few high-resolution abundance analyses of stars in this cluster are available. The bulge metal-poor clusters may be important tracers of the early chemical enrichment of the Galaxy.
Aims: The main purpose of this stud…
Revealing X-ray obscured quasars in SWIRE sources with extreme mid-IR/optical flux ratios
Salvato, M.; Fiore, F.; Vignali, C. +4 more
Recent works have suggested that selection criteria based on mid-IR properties, i.e. extreme colors and bright flux levels, can be used to reveal a population of dust-enshrouded, extremely-luminous quasars at z ∼ 1-2. However, the X-ray spectral properties of these intriguing objects still remain largely unexplored. We have performed an X-ray stud…
Small-scale oscillations in a quiescent prominence observed by HINODE/SOT. Prominence oscillations
Ichimoto, K.; Cao, W.; Qu, Z. Q. +2 more
Context: Investigations of the behavior of small-scale threads can provide an alternative approach to studying prominence dynamics and understanding its origin and nature.
Aims: The behavior of threads are analyzed in a quiescent prominence, including drifting and both the horizontally and vertically oscillating motions. These indicate waves i…
Photometric mass and mass decomposition in early-type lens galaxies
Grillo, C.; Rosati, P.; Lombardi, M. +1 more
Context: The largest spectroscopically selected sample of strong gravitational lens systems presented and analyzed to date is that of the Sloan Lens ACS (SLACS) survey. For the 57 massive early-type lens galaxies in the sample, photometric and spectroscopic measurements are available from the Sloan Digital Sky Survey (SDSS).
Aims: By using the…
Cosmic star-formation history from a non-parametric inversion of infrared galaxy counts
Elbaz, D.; Pichon, C.; Le Borgne, D. +1 more
Aims: This paper aims at providing new conservative constraints on the cosmic star-formation (SF) history from the empirical modeling of recent observations in the mid and far infrared.
Methods: We present a new empirical method based on a non-parametric inversion technique. It primarily uses multi-wavelength galaxy counts in the infrared and …
HD 174884: a strongly eccentric, short-period early-type binary system discovered by CoRoT
Auvergne, M.; Baudin, F.; Michel, E. +12 more
Accurate photometric CoRoT space observations of a secondary seismological target, HD 174884, led to the discovery that this star is an astrophysically important double-lined eclipsing spectroscopic binary in an eccentric orbit (e∼0.3), unusual for its short 3.65705° orbital period. The high eccentricity, coupled with the orientation of the binary…
The chemical abundance analysis of normal early A- and late B-type stars
Ryabchikova, T.; Fossati, L.; Alecian, E. +4 more
Context: Modern spectroscopy of early-type stars often aims at studying complex physical phenomena such as stellar pulsation, the peculiarity of the composition of the photosphere, chemical stratification, the presence of a magnetic field, and its interplay with the stellar atmosphere and the circumstellar environment. Comparatively less attention…
Magnetic flux emergence into the solar photosphere and chromosphere
Moreno-Insertis, F.; Tortosa-Andreu, A.
Aims: We model the emergence of magnetized plasma across granular convection cells and the low atmosphere, including layers up to the mid-chromosphere.
Methods: Three-dimensional numerical experiments are carried out in which the equations of MHD and radiative transfer are solved self-consistently. We use the MURaM code, which assumes local th…