References of "Remy, M."
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See detailOptical imaging of gravitational lenses B1422+231
Remy, M.; Surdej, Jean ULg; Smette, A. et al

in Surdej, Jean; Fraipont-Caro, D.; Gosset, Eric (Eds.) et al Liege International Astrophysical Colloquia,Gravitational Lenses in the Universe (1993)

We report here on some of the major developments achieved on optical observations of gravitational lenses since the last conference devoted to 'Gravitational Lensing'.

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See detailThe relative photometric lightcurve of UM673 A&B
Daulie, G.; Hainaut, O.; Hutsemekers, Damien ULg et al

in Surdej, Jean; Fraipont-Caro, Denise; Gosset, Eric (Eds.) et al The proceedings of the 31st Liège International Astrophysical Colloquium "Gravitational lenses in (1993)

From 1987 to 1993, we have carried out at ESO a photometric monitoring of the gravitationally lensed quasar UM673. The main result is that the two lensed images of UM673 did not show any significant ... [more ▼]

From 1987 to 1993, we have carried out at ESO a photometric monitoring of the gravitationally lensed quasar UM673. The main result is that the two lensed images of UM673 did not show any significant relative variation during more than five years. [less ▲]

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See detailThe cloverleaf quasar H1413+117: a preliminary light curve
Arnould, P.; Remy, M.; Gosset, Eric ULg et al

in Surdej, Jean; Fraipont-Caro, Denise; Gosset, Eric (Eds.) et al The proceedings of the 31st Liège International Astrophysical Colloquium "Gravitational lenses in the Universe" (1993)

The cloverleaf quasar H1413+117 was discovered to be a gravitational lens system in 1988. Since then, it has been photometrically monitored essentially as part of the ESO key-program Gravitational lensing ... [more ▼]

The cloverleaf quasar H1413+117 was discovered to be a gravitational lens system in 1988. Since then, it has been photometrically monitored essentially as part of the ESO key-program Gravitational lensing: we present here a first preliminary lightcurve for its four individual images. [less ▲]

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See detail'Gravitational lenses in the Universe', The proceedings of the 31st Liège International Astrophysical Colloquium
Surdej, Jean ULg; Fraipont-Caro, D.; Gosset, Eric ULg et al

Book published by Université de Liège (1993)

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See detailESO key programme, gravitational lensing: quasars and radio galaxies; a status report
Surdej, Jean ULg; Angonin, M. C.; Arnaud, J. et al

in Distribution of Matter in the Universe (1992, December 01)

The scientific background and objectives of our ESO Key Programme are first recalled. A brief account of our research activities (observing runs at ESO and elsewhere, meetings, etc.) is then given ... [more ▼]

The scientific background and objectives of our ESO Key Programme are first recalled. A brief account of our research activities (observing runs at ESO and elsewhere, meetings, etc.) is then given. Preliminary scientific results are presented concerning 1) our observational database for highly luminous quasars and distant powerful radiogalaxies; 2) speckle observations of highly luminous quasars; 3) the photometric monitoring and 4) detailed studies of several known gravitational lenses; 5) optical observations of 3C and 4C radio galaxies and 6) of the well known Einstein ring MG 1131+0456. [less ▲]

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See detailWorld Astronomy Day (WAD) Project #3: Astrophysical and Cosmological Tests Using Gravitational Lenses
Surdej, Jean ULg; Remy, M.; Haubold, H.

in Benvenuti, P.; Schreier (Eds.) ESO Conference and Workshop Proceedings, No. 44 (1992)

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See detailNew observations and gravitational lens models of the Cloverleaf quasar H1413 + 117
Kayser, R.; Surdej, Jean ULg; Condon, J. J. et al

in Astrophysical Journal (1990), 364

New optical and radio observations of the quadruple quasar H1413 + 117, the Cloverleaf, are presented. VLA data show radio counterparts at the positions of the four optical images and an additional strong ... [more ▼]

New optical and radio observations of the quadruple quasar H1413 + 117, the Cloverleaf, are presented. VLA data show radio counterparts at the positions of the four optical images and an additional strong radio source between images B and D. Gravitational lens models of H1413 + 117 using (1) a single elliptical galaxy and (2) two spherical galaxies are presented, which fit the positions of the four images of the quasar remarkably well. The models suggest that the strong radio source is a feature of the quasar, e.g., an ejected blob, which lies right on the caustic of the lens and is thereby strongly amplified. The time delays predicted by these models are sufficiently short to allow for their determination within one observational season, making H1413 + 117 an exceptionally well suited object for gravitational lens research. [less ▲]

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See detailAnalysis of the light variations of the Wolf-Rayet star WR16
Gosset, Eric ULg; Vreux, Jean-Marie ULg; Manfroid, Jean ULg et al

in Astronomy and Astrophysics. Supplement Series (1990), 84

This paper presents new data sets of Stromgren differential photometry observations of the Wolf-Rayet star WR16, collected at the ESO (La Silla, Chile). Results of detailed data analyses support previous ... [more ▼]

This paper presents new data sets of Stromgren differential photometry observations of the Wolf-Rayet star WR16, collected at the ESO (La Silla, Chile). Results of detailed data analyses support previous findings concerning the variability of WR16, with dominating power at frequencies below 1.5/d. The variations were found to be positively correlated on time lags up to about two days, a characteristic delay larger than the time of replacement of a typical WR star wind. A simple stochastic model is developed for the low frequency variability of the star, which is able to explain the available observations. [less ▲]

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See detailFirst spectroscopic evidence of microlensing on a BAL quasar? The case of H 1413 + 117
Angonin, M.-C.; Vanderriest, C.; Remy, M. et al

in Astronomy and Astrophysics (1990), 233

New data has been obtained for the quadruply lensed quasar H 1413 + 117 using the bidimensional spectrograph SILFID at the CFH telescope. The spectra recorded for each of the four individual images turn ... [more ▼]

New data has been obtained for the quadruply lensed quasar H 1413 + 117 using the bidimensional spectrograph SILFID at the CFH telescope. The spectra recorded for each of the four individual images turn out to be quite similar, except for the narrow absorption line systems (probably related to the lenses) seen in images A and B and for marked differences in the spectrum of image D. When compared to the three other images, the spectrum of D shows smaller values for the emission lines/continuum ratio and a larger equivalent width for absorption features located in the blueshifted P Cygni profile. The possible explanations of these observations are briefly discussed in terms of micro-lensing and/or intrinsic variability of the source. [less ▲]

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See detailFurther observations of the light echoes from SN 1987 A
Detal, Alain ULg; Surdej, Jean ULg; Hutsemekers, Damien ULg et al

in Astronomy and Astrophysics (1990), 229

Further direct observations of the light echoes from SN 1987 A were obtained on November 12 1988 with the 3.6-m telescope and EFOSC at ESO. In agreement with predictions made from earlier observations ... [more ▼]

Further direct observations of the light echoes from SN 1987 A were obtained on November 12 1988 with the 3.6-m telescope and EFOSC at ESO. In agreement with predictions made from earlier observations, the radii of the two light rings are measured to be 43.3 and 72.5 arcsec. However, a noticeable diaplacement of the center of the outer ring by 2.6 arcsec to the NE from the SN position is also reported. Application of the model of planar-like sheets of material located between the SN and the observer leads to improved results. [less ▲]

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See detailA search for gravitational lensing among highly luminous quasars - New results
Magain, Pierre ULg; Remy, M.; Surdej, Jean ULg et al

in Mellier, Y.; Fort, B.; Soucail, G. (Eds.) Gravitational Lensing (1990)

Images of highly luminous QSOs are analyzed to determine whether the gravitational magnification of the background QSO by matter associated with the foreground galaxies accounts for the excess of galaxies ... [more ▼]

Images of highly luminous QSOs are analyzed to determine whether the gravitational magnification of the background QSO by matter associated with the foreground galaxies accounts for the excess of galaxies in the fields of distant QSOs. Galaxy detection is increased by utilizing red-filter images, 40 taken with the EFOSC at the ESO 3.6-m telescope and 43 taken with a direct CCD camera at the ESO/MPI 2.2-m telescope. The R-magnitude ranges from 22.5 to 23.0 for the sample, for which the number of galaxies is counted by eye, showing 45 galaxies of radio and optical type. The overdensity found is not as pronounced as that of Fugmann (1988) or that of Webster et al. (1988). A systematic subtraction of the point spread function is also described to investigate the idea that some galaxies responsible for the QSO light magnification are within the inner 3-arcsec circle. The galaxies very close to the line-of-sight are theorized to contribute significantly to the magnification of these QSOs. [less ▲]

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See detailA search for gravitational lensing among highly luminous quasars - Observational strategy and survey
Swings, Jean-Pierre ULg; Magain, Pierre ULg; Remy, M. et al

in Soucail, G.; Mellier, Y.; Fort, B. (Eds.) Gravitational Lensing (1990)

The observational techniques employed to search for gravitational lensing effects in highly luminous quasars (HLQs) are given, along with results of the observations. The program, begun in 1986, considers ... [more ▼]

The observational techniques employed to search for gravitational lensing effects in highly luminous quasars (HLQs) are given, along with results of the observations. The program, begun in 1986, considers the visible and dark matter distributions at different scales in the universe to determine which extragalactic objects are gravitationally lensed. The Hubble parameter and galaxy masses are determined from the observations, and observations of microlensing effects provide data on HLQ size and structures. The redshifts are found to be between 1 and 3.6, with apparent visual magnitudes 16-18.5 and absolute visual magnitudes between -29 and -30.6. About one quarter of the images exhibit either multiple components, elongated structures, jetlike features, or faint nearby galaxies. The double quasar UM 673 and its 'overlying' lens galaxy is given as a prime example of an HLQ that is gravitationally lensed. It is theorized many more HLQs are gravitationally lensed, and specific future observations are recommended. [less ▲]

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See detailTwo more very massive stars resolved
Heydari-Malayeri, M.; Remy, M.; Magain, Pierre ULg

in Astronomy and Astrophysics (1989), 222

New evidence against the existence of very massive stars in the Magellanic Clouds is presented. Using high resolution CCD images and appropriate image restoration methods, it is shown that Sk 157 and Sk ... [more ▼]

New evidence against the existence of very massive stars in the Magellanic Clouds is presented. Using high resolution CCD images and appropriate image restoration methods, it is shown that Sk 157 and Sk-69 deg 253, lying in the SMC and LMC, respectively, are not single, very massive, but multiple systems. Thus, two of the most massive stars in existence, with the estimated masses of about 85 solar masses and greater than 120 solar masses vanish from astronomy. The results presented here have important implications for star formation models and the extragalactic distance scale. [less ▲]

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See detailNew results on the variability of some WN stars
Gosset, Eric ULg; Vreux, Jean-Marie ULg; Manfroid, Jean ULg et al

in Davidson, K.; Moffat, A. F. J.; Lamers, H.J.G.L.M. (Eds.) Physics of Luminous Blue Variables (1989)

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See detailNew evidence against the existence of very massive stars
Heydari-Malayeri, M.; Remy, M.; Magain, Pierre ULg

in Astronomy and Astrophysics (1988), 201

The most luminous stars are our first probes for exploring the stellar content of distant galaxies. They have also been used as standard candles for extragalactic distance determinations. The authors show ... [more ▼]

The most luminous stars are our first probes for exploring the stellar content of distant galaxies. They have also been used as standard candles for extragalactic distance determinations. The authors show that Sk -66°41, one of the brightest stars in the Large Magellanic Cloud (LMC), is a multiple system consisting of at least six components. This result has important consequences for the understanding of star formation mechanisms, especially the upper limit to stellar masses. Moreover, when primary distance indicators are not available, care should be taken in using the brightest blue stars. The derived distances, depending on the number of cluster members, can easily be underestimated by more than a factor 2, leading to larger values for the Hubble constant. [less ▲]

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See detailPreliminary results from a search for gravitational lensing within a sample of highly luminous quasars
Surdej, Jean ULg; Magain, Pierre ULg; Swings, Jean-Pierre ULg et al

in Balkowski, C.; Gordon, S. (Eds.) Proceedings to the First D.A.E.C. workshop on "Large Scale Structures" (1988)

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