Search Publications
Observational consequences of the recently proposed Super-Earth orbiting GJ 436
Bean, J. L.; Seifahrt, A.
Ribas and collaborators have recently proposed that an additional, ~5 M⊕ planet orbits the transiting planet host star GJ 436. Long-term dynamical interactions between the two planets leading to eccentricity excitation might provide an explanation for the transiting planet's unexpectedly large orbital eccentricity. We examine whether th…
Analysis of the Fe X and Fe XIV line width in the solar corona using LASCO-C1 spectral data
Schwenn, R.; Mierla, M.; Teriaca, L. +2 more
Aims:The purpose of this paper is to analyze the variation in the line width with height in the inner corona (region above 1.1 R⊙), by using the spectral data from LASCO-C1 aboard SOHO. We used data acquired at activity minimum (August-October 1996) and during the ascending phase of the solar cycle (March 1998).
Methods: Series of i…
Properties of high-degree oscillation modes of the Sun observed with Hinode/SOT
Kosovichev, A. G.; Mitra-Kraev, U.; Sekii, T.
Aims:With the Solar Optical Telescope on Hinode, we investigate the basic properties of high-degree solar oscillations observed at two levels in the solar atmosphere, in the G-band (formed in the photosphere) and in the Ca II H line (chromospheric emission).
Methods: We analyzed the data by calculating the individual power spectra as well as t…
Obscured and powerful AGN and starburst activities at z ~ 3.5
Berta, S.; Omont, A.; Stalin, C. S. +9 more
Aims: Short phases of coeval powerful starburst and AGN activity during the lifetimes of the most massive galaxies are predicted by various models of galaxy formation and evolution. In spite of their recurrence and high luminosity, such events are rarely observed. Finding such systems, understanding their nature, and constraining their number dens…
Integral field spectroscopy of four lensed quasars: analysis of their neighborhood and evidence for microlensing
Kneib, J. -P.; Faure, C.; Alloin, D. +4 more
Context: Gravitationally lensed quasars constitute an independent tool to derive the Hubble constant through the time-delays of their different images; they offer as well the opportunity to study the mass distribution and interstellar medium of their lensing galaxies and, through microlensing due to stars in their lensing galaxy, they also allow o…
A HST study of the environment of the Herbig Ae/Be star LkHα 233 and its bipolar jet
Ray, T. P.; Eislöffel, J.; Bacciotti, F. +3 more
Context: LkHα 233 is a Herbig Ae/Be star with a collimated bipolar jet. As such, it may be a high-mass analogue to the classical T Tauri stars and their outflows.
Aims: We investigate optical forbidden lines along the LkHα 233 jet to determine physical parameters of this jet (electron density ne, hydrogen ionisation fraction xe…
Multi-wavelength observations of a nearby multi-phase interstellar cloud
Boulanger, F.; Falgarone, E.; Le Bourlot, J. +3 more
Aims: High-resolution spectroscopic observations (UV HST/STIS and optical) are used to characterize the physical state and velocity structure of the multiphase interstellar medium seen towards the nearby (170 pc) star HD 102065. The star is located behind the tail of a cometary-shaped, infrared cirrus-cloud, in the area of interaction between the …
Stellar mass estimates in early-type galaxies from lensing+dynamical and photometric measurements
Grillo, C.; Rosati, P.; Lombardi, M. +1 more
Aims:Our purpose is to compare two different diagnostics for estimating stellar masses in early-type galaxies and to establish their level of reliability. In particular, we consider the well-studied sample of 15 field elliptical galaxies selected from the Sloan Lens ACS (SLACS) Survey (z = 0.06-0.33). We examine here the correlation between the st…
Improved estimates of the physical properties of the O-star binary V1007 Sco = HD 152248 and notes on several other binaries in the NGC 6231 cluster
Wolf, M.; Morrell, N.; Harmanec, P. +4 more
Context: In spite of the importance of massive O-type stars for astrophysics, their accurate masses and other fundamental properties are still a matter of debate. Determining them reliably is hampered by various factors (stellar winds and other forms of circumstellar matter), and the agreement of derived properties with the model predictions is fa…
The plasma filling factor of coronal bright points. Coronal bright points
Dere, K. P.
Aims: We determine the volumetric plasma filling factor of coronal bright points.
Methods: Rastered spectra of the regions of the quiet Sun were recorded by the Extreme ultraviolet Imaging Spectrometer (EIS) during operations with the Hinode satellite. Calibrated intensities of Fe XII lines were obtained and images of the quiet corona were con…