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Photocentric orbits from a direct combination of ground-based astrometry with Hipparcos. I. Comparison with known orbits
Gontcharov, G. A.; Kiyaeva, O. V.
Complementing the Proper Motions of Fundamental Stars catalogue by Gontcharov et al. (CDS, I-266) the photocentric orbits of some FK5/Hipparcos stars are calculated in a direct combination of the Hipparcos data with astrometric ground-based observational catalogues having epochs later than 1939. Some capabilities and limitations of this method are…
A high-resolution study of the evolution of the Lyman alpha forest in the redshift interval 0.9 < z < 1.7
Reimers, D.; Janknecht, E.; Baade, R.
Spectroscopy with HST/STIS Echelle and VLT/UVES of the bright QSO HE 0515-4414 (zem =1.73, B = 15.0) offers for the first time the opportunity to study the Lyman alpha forest in the redshift range 0.9 < z < 1.7 at a resolution <=10 km s-1. The number density evolution of the Lyman alpha lines is well described by the…
Relation between dust and radio luminosity in optically selected early type galaxies
Jaffe, W.; Krajnović, D.
We have surveyed an optical/IR selected sample of nearby E/S0 galaxies with and without nuclear dust structures with the VLA at 3.6 cm to a sensitivity of 100 mu Jy. We can construct a Radio Luminosity Function (RLF) of these galaxies to ~ 1019 W Hz-1 and find that ~ 50% of these galaxies have AGNs at this level. The space de…
Multiwavelength optical observations of chromospherically active binary systems. IV. The X-ray/EUV selected binary BK Psc (2RE J0039+103)
Montes, D.; López-Santiago, J.; Cornide, M. +3 more
We present high resolution echelle spectra taken during four observing runs from 1999 to 2001 of the recently X-ray/EUV selected chromospherically active binary BK Psc (2RE J0039+103). Our observations confirm the single-lined spectroscopic binary (SB1) nature of this system and allow us to obtain, for the first time, the orbital solution of the s…
Mira kinematics in the post-Hipparcos era
Schilbach, E.; Kharchenko, N.; Malkov, O. +1 more
The complete data set of Mira variables from the 4th edition of the General Catalog of Variable Stars was analyzed and supplemented by the proper motions and radial velocities presently available for Miras. The resulting sample of 724 Miras with periods between 78 and 612 days contains proper motions reduced to the Hipparcos system, radial velocit…
XMM-Newton observations of MR Vel/RX J0925.7-4758
Motch, C.; Neiner, C.; Bearda, H.
We report on XMM-Newton observations of the galactic supersoft X-ray source
Stokes parameters of resonance lines scattered by a moving, magnetic medium. Theory of the two-level atom
Raouafi, N. -E.
The aim of the present work is to present theoretical results on the Stokes parameters of a resonance spectral line, scattered by moving atoms (or ions) in the presence of a local magnetic field. We assume that the scattered line is sensitive to the Hanle effect due to the magnetic field and also to Doppler redistribution due to the atomic motions…
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 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…