The Ca II triplet lines in Starburst and AGN

In the frame of the Starburst Model for AGN, we show that the evolution of a massive stellar cluster in a high metallicity environment can reproduce the observed equivalent widths of Ca II triplet lines in absorption in Starburst and active galactic nuclei. In the case of Starburst galaxies, this strength, together with the emission-line ratio [O II]/[O III], can be used to determine the age of the cluster. The strength of the Ca II lines is mainly governed by the age of the stellar cluster through the presence of red supergiant stars.     

A population synthesis model for the ultraviolet spectrum of the peculiar galaxy NGC 1672

We present a stellar population synthesis model for the UV spectrum of the peculiar galaxy NGC 1672, computed with the use of theIUE Atlas Library of Stellar Spectra.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Chromospheric variability in late-type dwarfs from high-resolution spectra of Caii H

Precise photometric observations of stars in the double cluster h and Persei reveal a large spread in the colours and magnitudes of the upper Main-Sequence; half of the stars are variables that are Be stars or related stars. The reported age difference between both clusters is found to be spurious. Rotation apparently affects both the intrinsic and the observed colours of the early-type stars in h and Persei. This result questions the validity of photometric calibrations that heavily rely on h and Persei or similar clusters.Paper presented at the 11th European Regional Astronomical Meeting of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Phase shifts between colours in pulsating stars

Observational evidence is presented showing that the time of maximum light for pulsating stars depends on observed wavelength. This fact is well explained by assuming that starlight variations comets from both temperature and gravity variations. Conversely, from the time shifts between two colours, temperature and gravity variations can be derived, together with the phase lag between them.Partially based on observations collected at European Southern Observatory, La Silla, Chile.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Spectral behaviour of the eclipsing binary TX UMa around primary minimum

Sixty-one blue spectrograms of TX UMa were obtained in the years 1969–1970, mainly in phases close to the primary minimum of the eclipsing system. The radial velocity curve displays clear rotational effect from which much higher than synchronous rotational velocity of the blue (B8V) component has been formally derived. However, this discrepancy is probably due to the presence of the tenous accretion disk around the primary. The disk is apparently fed by the intermittent mass transfer as indicated by the occasional changes of orbital period of the system. From all available radial velocity data an improved set of spectroscopic orbital elements is derived. The behaviour of the spectral lines in and out of the primary minimum is compared. Metallic lines of the cold (F7IV) secondary component are clearly seen exclusively in phases 0.988 to 0.012.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

On the continuum intensity-magnetic field relation along the decay phase of sunspots

We present continuum intensity-magnetic field distributions for a decaying sunspot. It is shown that a very simple model accounts for the observed correlation. The Wilson depression is determined.Based on observations made with the Vacuum Gregory Telescope (V.G.T.) and the Vacuum Newton Telescope (V.N.T.) operated on the island of Tenerife by the Universitäts-Sternwarte Göttingen and the Kiepenheuer-Institut at the Observatorio del Teide of the Instituto de Astrofisica de Canarias.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Galaxy clustering in the nonlinear regime

We calculate the r.m.s. density fluctuations using the ID Zel'dovich approximation implemented with a virialization scheme for the very dense fluctuations. The results are quite different from those found in the linear regime with strong implications for the normalization of the power spectrum of the initial density fluctuations. We also calculate the nonlinear two-point correlation function for matter with an initial spectrum (equivalent to white noise in 3D) of fluctuations; differences from the linear approximation appear at scales much larger than those considered previously of 10h ^–1 Mpc.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

CCD surface photometry of the Seyfert 1 galaxy NGC 4151

We present CCD surface photometry of the central region of the bright Seyfert 1 galaxy NGC 4151. The observations were obtained under excellent seeing conditions (0.75 FWHM). Morphological parameters for the bulge of the galaxy are estimated from the observed broad bandV, R, andI surface brightness profiles.From the analysis of the colour maps two distinct nuclear structures emerge perpendicular to each other. One of them is elliptically elongated at PA angle 50°. This direction is close to the direction of the radio jets and coincides with the Extended Narrow Emission Line Region (ENELR). Its extension is about 7 arc sec and its colours are bluer than the surronding bulge. The second structure is smaller in extension (about 1 arc sec) and is elongated at PA130°. Its colours are redder than those of the surrounding bulge. It is suggested that this might constitute areal extension of the Broad Line Region (BLR).Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Data acquisition interfaces for GHRIL ITV-IPD detectors

So as to meet the requirements of high spatial resolution techniques, two data acquisition interfaces for ITV and IPD detectors have been developed. These permit a synchronized and simultaneous observation between both of them. The synchronized temporal resolution is 20ms, as well as the data of the ITV, while the reading interface from the IPD permits a temporal resolution of 50s. The ITV signal is stored on the video-recorder while the IPD interface is developed through transputers which store the data, with the time tags, on computer disc.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain     

(Super) cosmological solution for the Kasner model

In the theory of supergravity (N=1), the supersymmetric version of general relativity, and for the Kasner cosmological model (Bianchi type I) we find a non-trivial solution (for the metric and spinor-vector) under the most simple assumption =₁₁ + ₂₂; ₁₂+₂₁=0 and for a special choosed gaugeN=1,N ^j=0, ₀=0. This method could be also applied to other cosmological metrics and extended to enlarged Grassmann basis.O. Obregón was partially supported by the Alexander von Humboldt Stiftung.