Search Publications
Nuclear disks of gas and dust in Fanaroff-Riley type I radio host galaxies: 3C 402N and NGC 7052.
de Juan, L.; Colina, L.; Golombek, D.
A nuclear disk of gas and dust is detected in the host galaxy of the Fanaroff-Riley type I (FR-I) radio source 3C 402N, using pre-COSTAR HST/FOC images, and high spatial resolution ground-based broad-band and Hα+[NII] narrow-band images. The physical properties of the nuclear disk in the B2 2116+26 host galaxy (NGC 7052) are also presented. On ave…
Are the pulses of the Crab pulsar modulated?
Cadez, A.; Galicic, M.
We present the results of optical Crab pulsar observations which were designed to search for short-time variations in pulsar's light-curve. Hubble Space Telescope (High Speed Photometer) data and photometric data obtained at the Asiago 1.82m telescope using a specially designed stroboscopic chopper have been analysed and compared. We find a very w…
A new HST image of Cygnus A .
Sparks, W. B.; Macchetto, F.; Miley, G. K. +2 more
We present a new HST image of Cygnus A, taken in the V-band. This image includes both continuum and lines of [0III], and shows the major, northwestern and southeastern components, together with the weaker central component. Filamentary structure is present at this resolution of 0.045". This structure runs generally parallel to the radio jet and ma…
The high latitude pass of ULYSSES: energetic particle observations with EPAC.
Keppler, E.; Korth, A.; Fraenz, M. +4 more
We report on observations of energetic particles (EP) during the ascent of ULYSSES to the south pole, on the fast pass from south to north and in the first few months after the north polar pass. After it left the ecliptic plane the spacecraft moved periodically into a corotating (26 days period) fast solar wind stream and observed the accelerated …
On the spread of ages among the young stars in the LMC association NGC 1948.
Bomans, D. J.; de Boer, K. S.; Vallenari, A. +2 more
The ages of the young associations located at the border of the supergiant shell LMC4 are essential parameters to understand the formation and the evolution of that supergiant shell. We present spectra in the UV and the optical wavelength range of eleven stars in NGC 1948 in order to establish the location of the top of the main sequence more accu…
An ISOPHOT study of the disk of galaxy NGC 6946: 60µminfrared and radio continuum correlation.
Helou, G.; Malhotra, S.; Xu, C. +4 more
We use the ISOPHOT 60µmimage of Tuffs et al. (1996) to study the 60µmlight distribution and its correlation with radio continuum within the disk of spiral galaxy NGC 6946, and to resolve the long-standing IRAS controversy as to whether the infrared-to-radio continuum ratio, Q, decreases radially out in galaxy disks. Our main results ar…
ISOCAM view of high energy sources.
Mirabel, I. F.; Boulade, O.; Claret, A. +2 more
We report the discovery of warm dust in the surroundings of the compact high energy sources SS433 and Cygnus X-1. In the jets of SS433 we have observed the infrared counterpart of the brighter X-ray knot at a distance of 50pc from the compact source. The observation reported here suggests that dust formation takes place in the ejecta, and that the…
Nonlinear variability of NGC 4151.
Longo, G.; Vio, R.; Rifatto, A. +2 more
We have collected all literature photometric data obtained in the B band for the Seyfert galaxy NGC4151 over the period 1910-1991, reduced them to the standard B_T_ photometric system and derived nuclear magnitudes by subtracting the light contribution from the underlying extended bulge component. The spectral analysis of the light curve shows no …
Time variable shocks in the UV: long term IUE monitoring of HH 29.
Liseau, R.; Huldtgren, M.; Fridlund, C. V. M. +1 more
We have used the IUE to the limit of its capability (~10^-15^erg/cm^2^/s/A) and present results based on long term monitoring in the UV of the Herbig-Haro object HH 29, which is dynamically coupled to the outflow activity from the deeply embedded low mass stellar object IRS5 in the L1551 dark cloud. The eight years of IUE observations confirm the …
ISO observations of the classical nova V1974 Cygni.
Kessler, M. F.; Eyres, S. P. S.; Salama, A. +3 more
We present observations of the classical nova V1974 Cygni (Nova Cyg 1992) obtained with the ISO Short and Long Wavelength Spectrometers (SWS and LWS) and the spectrometer section of ISOPHOT. We identify [NeIII]λ15.5, [NeV]λ14.3, 24.3, [NeVI]λ7.6, [OIII]λ51.8, [OIV]λ25.9. There is evidence that the Ne and O emission arises in physically distinct re…