Search Publications
M2000: An astrometric catalog in the Bordeaux Carte du Ciel zone +11degr <= delta <= +18degr
Ducourant, C.; Soubiran, C.; Le Campion, J. -F. +11 more
During four years, systematic observations have been conducted in drift scan mode with the Bordeaux automated meridian circle in the declination band +11degr <= delta <= +18degr . The resulting astrometric catalog includes about 2.3x 106 stars down to the magnitude limit VM=16.3. Nearly all stars (96%) have been observe…
NLTE accretion disc models for the AM Canum Venaticorum systems
Nasser, M. R.; Solheim, J. -E.; Semionoff, D. A.
We present models of the optical spectra of two types of accretion disc atmospheres: a pure helium model and a H-He model, in a low mass ratio, helium transferring, interacting binary white dwarf system. The computations are restricted to stationary discs in LTE and NLTE cases. We also investigate the influence on the spectra of some of the disc p…
The variable XMM-Newton spectrum of Markarian 766
Kaastra, J. S.; Clavel, J.; Page, M. J. +10 more
The narrow-line Seyfert 1 galaxy Markarian 766 was observed for 60 ks with the \xmm\ observatory. The source shows a complex X-ray spectrum. The 2-10 keV spectrum can be adequately represented by a power law and broad Fe Kalpha emission. Between 0.7 and 2 keV the spectrum is harder and exhibits a flux deficit with respect to the extrapolated mediu…
Cold gas kinematics in an L* spiral Galaxy at z = 0.437: The nature of Damped Lyman-alpha absorbers
de Bruyn, A. G.; Briggs, F. H.; Vermeulen, R. C.
Westerbork Radio Synthesis Telescope observations of the redshifted 21 cm line absorber against the zem = 0.871 double lobed quasar 3C 196 show that the intervening absorber is an L~ L* spiral galaxy (3C 196-G1) and that the absorbing layer of cold gas extends to radii of at least 30 h50-1 kpc. The new d…
High-resolution O VI absorption line observations at 1.2 <= z <= 1.7 in the bright QSO HE 0515-4414
Reimers, D.; Hagen, H. -J.; Baade, R. +1 more
STIS Echelle observations at a resolution of 10 km s-1 and UVES/VLT spectroscopy at a resolution of 7 km s-1 of the luminous QSO HE 0515-4414 (zem = 1.73, B = 15.0) reveal four intervening O Vi absorption systems in the redshift range 1.21 <= zabs <= 1.67 (1.38503, 1.41601, 1.60175, 1.67359). In ad…
A high resolution spectroscopic observation of CAL 83 with XMM-Newton/RGS
de Vries, C. P.; Heise, J.; Brinkman, A. C. +4 more
We present the first high resolution photospheric X-ray spectrum of a Supersoft X-ray Source, the famous CAL 83 in the Large Magellanic Cloud. The spectrum was obtained with the Reflection Grating Spectrometer on XMM-Newton during the Calibration/Performance Verification phase of the observatory. The spectrum covers the range 20-40 Å at an approxi…
On the relation between total irradiance and radius variations
Varadi, F.; Rozelot, J. P.; Pap, J. +1 more
We use Singular Spectrum Analysis (SSA) to analyze total solar irradiance variations and CERGA radius measurements. Total solar irradiance has been monitored from space for more than two decades, whilst ground-based radius measurements are available as a coherent time series from 1975. We compare these indicators to try to understand the origin of…
The first ISO ERO: A dusty quasar at z = 1.5
Cesarsky, C.; Lidman, C.; Pierre, M. +9 more
We report the discovery of an extremely red object (ERO) in a medium-deep ISOCAM extragalactic survey. The object is also a radio source. Subsequent VLT NIR spectroscopy revealed a prominent Hα line giving a redshift of 1.5. We present the spectrum and photometric data points and discuss evidence that ISO J1324-2016 is a quasar harbouring a signif…
XMM-Newton monitoring of X-ray variability in the quasar PKS 0558-504
O'Brien, P. T.; Reeves, J. N.; Brinkmann, W. +4 more
We present the temporal analysis of X-ray observations of the radio-loud Narrow-Line Seyfert 1 galaxy (NLS1)
Stellar luminosity functions of rich star clusters in the Large Magellanic Cloud
Santiago, B.; Gilmore, G. F.; Beaulieu, S. +1 more
We show the results of deep V and I HST photometry of 6 rich star clusters in the Large Magellanic Cloud with different ages and metallicities. The number of stars with measured magnitudes in each cluster varies from about 3000 to 10 000 stars. We build stellar density and surface brightness profiles for the clusters and extract half-light radii a…