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  1. No Access

    Article

    In-flight performance of the IUE

    After the IUE's successful launch into an eccentric geosynchronous orbit, and following initial spacecraft checkout, observations were made of a set of high priority targets as an insurance against premature f...

    A. Boggess, R. C. Bohlin, D. C. Evans, H. R. Freeman, T. R. Gull, S. R. Heap… in Nature (1978)

  2. No Access

    Chapter and Conference Paper

    Ultraviolet, Optical and X-Ray Monitoring of the Continuum of NGC 4151

    The nucleus of the Seyfert galaxy NGC 4151 has been extensively monitored with the International Ultraviolet Explorer (IUE) in the wave- length range 1200–3000 Å, a region of the spectrum where the contaminati...

    G. C. Perola, A. Boksenberg, G. E. Bromage, J. Clavel, M. Elvis… in X-Ray Astronomy (1981)

  3. No Access

    Article

    Ultraviolet, optical and X-ray monitoring of the continuum of NGC 4151

    G. C. Perola, A. Boksenberg, G. E. Bromage, J. Clavel, M. Elvis… in Space Science Reviews (1981)

  4. No Access

    Chapter and Conference Paper

    Simultaneous Exosat-IUE Observations of NGC 4151

    NGC 4151 was observed four times in Nov. 83. The results indicate that: a) there exists a correlation between the X-ray and UV fluxes on the long term; b) the soft X-ray excess between 0.1 and 1 keV is probabl...

    G. C. Perola, A. Altamore, A. Boksenberg… in X-Ray Astronomy in the Exosat Era (1985)

  5. No Access

    Article

    Narrow and variable lines in the ultraviolet spectrum of the Seyfert galaxy NGC4151

    The Seyfert galaxy NGC4151 observed when the nucleus is at a minimum has two emission lines of full width at half maximum <7 and 16 Å respectively and varying in intensity by a factor of three in 10 days. Thes...

    M. H. Ulrich, A. Altamore, A. Boksenberg, G. E. Bromage, J. Clavel, A. Elvius… in Nature (1985)

  6. No Access

    Article

    Simultaneous EXOSAT-IUE observations of NGC 4151

    NGC 4151 was observed four times in Nov. 83. The results indicate that: a) there exists a correlation between the X-ray and UV fluxes on the long term; b) the soft X-ray excess between 0.1 and 1 keV is probabl...

    G. C. Perola, A. Altamore, A. Boksenberg, G. E. Bromage, J. Clavel… in Space Science Reviews (1985)

  7. No Access

    Chapter

    Discovery of Narrow and Variable Lines in the Ultraviolet Spectrum of the Seyfert Galaxy NGC 4151, and an Outline of Our Previous Results

    Extensive observations of NGC 4151 when the nucleus is at a minimum have led to the discovery of two emission lines which have a full width at half maximum of less than 7 and 16 Å respectively (after correctio...

    M. H. Ulrich, A. Altamore, A. Boksenberg… in Structure and Evolution of Active Galactic… (1986)

  8. No Access

    Chapter

    T Cor B, a “Seyfert 1 Nucleus” at 1200±100 Parsecs?

    Several symbiotic stars are characterized by UV spectral signatures which are similar, in several aspects, to those observed in the broad-line region of Seyfert galaxies. We suggest to consider the symbiotic s...

    P. L. Selvelli, J. Clavel, A. Cassatella… in Structure and Evolution of Active Galactic… (1986)

  9. No Access

    Article

    The progenitor of SN1987A

    One of the reasons why the bright supernova SN1987A is of such importance is the fact that its proximity would allow for the first time, the identification of a supernova progenitor star. Attempts to establis...

    R. Gilmozzi, A. Cassatella, J. Clavel, C. Fransson, R. Gonzalez, C. Gry… in Nature (1987)

  10. No Access

    Chapter and Conference Paper

    FeII and Balmer continuum emission in AGNs

    We address in this short note a different aspect of the FeII problem in AGNs, one connected with treating the total FeII emission as a form of “continuum” rather than emission lines. The justification for this...

    R. Gilmozzi, W. Wamsteker, J. Clavel… in Physics of Formation of FeII Lines Outside… (1988)

  11. No Access

    Chapter

    Urinary Calcium After Oral Glucose Ingestion in Calcium Stone Formers: A Simple Provocative Test for Predicting Stone Recurrence

    Although the various metabolic abnormalities underlying Ca stone disease have been extensively studied, none of these except abnormalities in 24-h urine samples appear to be of any practical significance as pr...

    M. Normand, J.-P. Bouvet, J.-L. Cayotte, J. Clavel, A. Ulmann in Urolithiasis (1989)

  12. No Access

    Article

    The O/C abundance ratio in absorbing gas clouds at high redshift

    THE intrinsic extreme ultraviolet (EUV) spectrum of quasars, in which spectral lines of He and CNO ions should appear, is in most cases strongly absorbed by the hydrogen Lyman continuum of intergalactic matter...

    D. Reimers, S. Vogel, H.-J. Hagen, D. Engels, D. Groote, W. Wamsteker, J. Clavel… in Nature (1992)

  13. No Access

    Chapter and Conference Paper

    The Iue Ultraviolet Spectrum of PC 11

    PC 11 (HD 149427, PK 331–5 1) is classified as a young planetary nebula with strong OIII 4363Å and a Zanstra temperature of T Z = 27000K. It is also classified as (D’ - type) ye...

    M. Parthasarathy, S. R. Pottasch, J. Clavel in Planetary Nebulae (1993)

  14. No Access

    Chapter

    The International AGN Watch: A Multiwavelength Monitoring Consortium

    The International AGN Watch, an informal consortium of over 100 astronomers, was established to coordinate multiwavelength monitoring of a limited number of active galactic nuclei and thus obtain comprehensive...

    D. Alloin, J. Clavel, B. M. Peterson… in Frontiers of Space And Ground-Based Astron… (1994)

  15. No Access

    Chapter

    The Infrared Space Observatory (ISO)

    The Infrared Space Observatory (ISO) is a three axis stabilized satellite designed to observe astronomical sources in the range 2.5–200 µm. It contains a cryogenically cooled telescope feeding four focal plane in...

    J. Clavel, M. F. Kessler in Frontiers of Space And Ground-Based Astronomy (1994)

  16. No Access

    Chapter and Conference Paper

    High-Resolution Spectroscopy of the Bright Quasar HS 1946+7658

    The optical spectrum of the QSO HS 1946+7658 (z em = 3.05) has been observed at high resolution (b ~ 15km/s) in the wavelength interval 4115 – 4970Å. Th...

    A. de la Fuente, Rodríguez-Pascual, J. L. Sanz, M. C. Recondo… in QSO Absorption Lines (1995)

  17. No Access

    Chapter and Conference Paper

    The Lyα Forest towards HS1700+6416 at High Resolution

    We have analyzed high resolution (b ≈ 15 km/s) optical spectra of the QSO HS1700+6416 (z em = 2.72). The high S/N ratio in the Lyα forest allows a reasonable de...

    P. M. Rodríguez-Pascual, A. de la Fuente, J. L. Sanz, M. C. Recondo… in QSO Absorption Lines (1995)

  18. No Access

    Chapter and Conference Paper

    Metal Line Absorptions Toward the QSO HS1700+6416

    We have analyzed high resolution (b ≈ 15 km/s) and low resolution (R ≈ 3Å) optical spectra of the QSO HS1700+6416 (z em = 2.72) taken with the ISIS spectrograph at the WHT. We are able to ...

    J. L. Sanz, P. M. Rodríguez-Pascual, A. de la Fuente, M. C. Recondo… in QSO Absorption Lines (1995)

  19. No Access

    Article

    ISO Observations of Symbiotic Stars

    A number of symbiotic stars have been observed with ISO. In addition to a number of emission lines, SWS observations of the symbiotic novae RR Tel and V1016 Cyg reveal prominent, broad 10 & 18 µm silicate dust...

    S.P.S. Eyres, A. Evans, A. Salama, P. Barr, J. Clavel… in Astrophysics and Space Science (1997)

  20. No Access

    Article

    ISO Observations of Classical Novae

    We describe the ISO programme to observe classical novae. The programme includes observations of novae during and shortly after eruption, and old novae. ISO observations of far infrared fine structure lines ar...

    A. Salama, P. Barr, J. Clavel, R. N. Jenkins, K. Leech… in Astrophysics and Space Science (1997)

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