Search Publications
An excess of mid-IR luminous galaxies in Abell 1689?
Elbaz, D.; Duc, P. -A.; Franceschini, A. +4 more
We present the results of infrared observations of Abell 1689, an exceptionally rich cluster of galaxies at intermediate redshift (z^simeq 0.181). It was observed with ISOCAM, at 6.7 mum and 15 mum , and ISOPHOT at 200 mum from the Infrared Space Observatory (ISO). The cluster galaxies detected above a sensitivity limit of 0.15 mJy in the 6.7 mum …
Damped Lyman alpha systems at z=0.68 and z=1.15 towards HE 1122-1649 and HE 0515-4414
Reimers, D.; Burles, S.; Tytler, D. +2 more
Detailed analysis of the spectral lines from two low redshift damped Lyman alpha absorbers (DLA) confirms that they are a heterogeneous population. Both systems have low metal abundances of approximately 0.05 to 0.1 solar. The abundance pattern of the DLA at z=1.15 towards HE 0515-4414 shows dust depletion comparable to that found in our Galaxy, w…
Atomic diffusion in metal poor stars. The influence on the Main Sequence fitting distance scale, subdwarfs ages and the value of Delta Y/ Delta Z
Salaris, M.; Weiss, A.; Groenewegen, M. A. T.
The effect of atomic diffusion on the Main Sequence (MS) of metal-poor low mass stars is investigated. Since diffusion alters the stellar surface chemical abundances with respect to their initial values, one must ensure - by calibrating the initial chemical composition of the theoretical models - that the surface abundances of the models match the…
Solar energetic particle event and radio bursts associated with the 1996 July 9 flare and coronal mass ejection
Laitinen, T.; Torsti, J.; Klein, K. -L. +6 more
Using spaceborne particle and gamma-ray detection and radio diagnostics we study solar energetic particle (SEP) production in the 1996 July 9 event. This event is associated with an impulsive soft X-ray flare (9:10 UT) and a coronal mass ejection (CME). In a global classification the event is considered as mixed-impulsive. A sequence of accelerati…
Non-equilibrium H_2 ortho-to-para ratio in two molecular clouds of the Galactic Center
Rodríguez-Fernández, N. J.; Martín-Pintado, J.; Fuente, A. +4 more
We present ISO observations of the S(0), S(1), S(2), and S(3) rotational lines of molecular hydrogen from two molecular clouds near the Galactic Center (GC). We have also measured continuum dust emission at infrared wavelengths with ISO and the rotational radio lines J=1-0 of 13CO and C18O and J=2-1 of C18O with th…
First detections of FIRBACK sources with SCUBA
Clements, D. L.; Dole, H.; Lagache, G. +10 more
The FIRBACK (Far InfraRed BACKground) survey represents the deepest extensive 170 µm images obtained by the ISO satellite. The sources detected comprise about 10% of the Cosmic IR Background (CIB) seen by COBE, and, importantly, were observed at a wavelength near the peak of the CIB. Detailed follow-up of these sources should help pin down t…
The dynamical evolution of the fragmented, bipolar dust shell around the carbon star IRC +10 216 . Rapid changes of a PPN-like structure?
Weigelt, G.; Men'shchikov, A. B.; Blöcker, T. +2 more
We present high-resolution J-, H-, and K-band observations and the first H-K color image of the carbon star
Circumnuclear structure and kinematics in the active galaxy NGC 6951
Durret, F.; González Delgado, R. M.; Moles, M. +5 more
A study is presented of the central structure and kinematics of the galaxy NGC 6951, by means of broad band B{\arcminIJK} images and high resolution high dispersion longslit spectroscopy, together with archival HST WFPC2 V and NICMOS2 J and H images. We find that there is little ongoing star formation inside the bar dominated region of the galaxy,…
Sensitivity of the GOLF signal to combined solar velocity and intensity variations
García, R. A.; Turck-Chièze, S.; Dzitko, H. +6 more
The GOLF instrument provides a stable and continuous measurement of the intensity of spatially integrated sunlight in one wing of the sodium D lines. Because the detected radiation results from atomic scattering, the GOLF signal can be traced to an atomic reference wavelength. The planned operations were to involve a form of relative photometry th…
Rapid intensity and velocity variations in solar transition region lines
Hansteen, V. H.; Carlsson, M.; Betta, R.
We have obtained short exposure (3 s) time series of strong upper chromospheric and transition region emission lines from the quiet Sun with the SUMER instrument onboard SOHO during two 1 hour periods in 1996. With a Nyqvist frequency of 167 mHz and relatively high count rates the dataset is uniquely suited for searching for high frequency variati…