Search Publications
A study of accretion discs around rapidly rotating neutron stars in general relativity and its applications to four low mass X-ray binaries
Bhattacharyya, Sudip
We calculate the accretion disc temperature profiles, disc luminosities and boundary layer luminosities for rapidly rotating neutron stars considering the full effect of general relativity. We compare the theoretical values of these quantities with their values inferred from EXOSAT data for four low mass X-ray binary sources: XB 1820-30, GX 17+2, …
HD 112 mu m in absorption and extreme CO depletion in a cold molecular cloud
Maret, S.; Ceccarelli, C.; Pagani, L. +3 more
We present ISO-LWS observations at high spectral resolution (R ~ 104) towards a cold molecular cloud in the line of sight of W49. The HD ground state transition at 112 mu m is detected, showing the first observation of this line in absorption outside the solar system. The 112 mu m absorption depth gives a straightforward measure of the …
The Gravitational Lens CFRS 03.1077
Le Fèvre, O.; Crampton, David; Lilly, S. J. +3 more
An exquisite gravitational arc with a radius of 2.1" has been discovered around the z=0.938 field elliptical galaxy CFRS 03.1077 during HST observations of Canada-France Redshift Survey (CFRS) fields. Spectroscopic observations of the arc show that the redshift of the resolved lensed galaxy is z=2.941. This gravitational lens source system is well…
The 3-D ionization structure of the planetary nebula NGC 6565
Sabbadin, F.; Turatto, M.; Cappellaro, E. +2 more
A detailed study of the planetary nebula NGC 6565 has been carried out on long-slit echellograms (lambda /Delta lambda =60 000, spectral range = lambda lambda 3900-7750 Å) at six, equally spaced position angles. The expansion velocity field, the c(Hβ ) distribution and the radial profile of the physical conditions (electron temperature and density…
14-day forecast of solar indices using interplanetary Lyman α background data
Bertaux, Jean-Loup; Quémerais, Eric
We present a new method which can be used to forecast the variations of solar indices on the time scale of a half solar rotation. This method uses the Lyα interplanetary glow data obtained by the SWAN instrument on SOHO. We show how the maps of solar Lyα flux distributions derived from the SWAN data can be linked to the variation of activity on th…
Multiwavelength evidence for a 15-year periodic activity in the symbiotic nova V1016 Cygni
Chochol, D.; Buson, L. M.; Vittone, A. A. +2 more
The ~ 15.1 years period found in the long-term UBV photoelectric and photographic photometry of the symbiotic nova V1016 Cyg is detected also in the (J-K) colour index and in the UV continuum and emission line fluxes from IUE and HUT spectra. It could be interpreted either as the effect of recurrent enhanced mass loss episodes from the Mira type v…
Asteroids observations with the Hubble Space Telescope. I. Observing strategy, and data analysis and modeling process
Lattanzi, M.; Tanga, P.; Berthier, J. +5 more
Five main belt asteroids and one Trojan - selected mainly on the basis of their possible binary nature as deduced from light curve morphology - have been observed with the Fine Guidance Sensors (FGS#3 and FGSR#1) of the Hubble Space Telescope (HST). In this first paper we present the selection and observation strategy, data reduction and analysis.…
Search for duplicity in periodic variable Be stars
Carrier, F.; Burki, G.; Burnet, M.
Four Be stars,
Heating in Coronal Funnels by Ion Cyclotron Waves
Li, Xing
Plasma heating by ion cyclotron waves in rapidly expanding flow tubes in the transition region, referred to as coronal funnels, is investigated in a three-fluid plasma consisting of protons, electrons, and α-particles. Ion cyclotron waves are able to heat the plasma from 6×104 to 106 K over a distance range of 104 …
On the theory of MAG waves and a comparison with sunspot observations from CDS/SoHO
Doyle, J. G.; Poedts, S.; Banerjee, D. +2 more
We examine the influence of non-adiabatic effects on the modes of an isothermal stratified magnetic atmosphere. We present new solutions for magneto-acoustic-gravity (or MAG) waves in the presence of a radiative heat exchange based on Newton's law of cooling. An analytic expression for the dispersion relation is derived, which allows the effect of…