Search Publications
Testing the inverse-Compton catastrophe scenario in the intra-day variable blazar S5 0716+71 . II. A search for intra-day variability at millimetre wavelengths with the IRAM 30 m telescope
Grewing, M.; Britzen, S.; Wagner, S. J. +12 more
We report on a densely time sampled polarimetric flux density monitoring of the BL Lac object
VIMOS-IFU survey of z ~ 0.2 massive galaxy clusters. I. Observations of the strong lensing cluster Abell 2667
Kneib, J. -P.; Jullo, E.; Richard, J. +3 more
We present extensive multi-color imaging and low-resolution VIMOS integral field unit (IFU) spectroscopic observations of the X-ray luminous cluster Abell 2667 (z=0.233). An extremely bright giant gravitational arc (z=1.0334 ± 0.0003) is easily identified as part of a triple image system, and other fainter multiple images are also revealed by the …
Detection of water ice grains after the DEEP IMPACT onto Comet 9P/Tempel 1
Rodriguez-Pascual, P. M.; Schulz, R.; Lumb, D. +3 more
Context: Icy grains in the inner coma of a comet may play an important role in the energy balance and in the production of certain gas coma species. Their existence has therefore been assumed repeatedly to explain a variety of observed phenomena. However, owing to their extremely short life time no evidence for the presence of icy grains had been …
Seasonal variations of the martian CO over Hellas as observed by OMEGA/Mars Express
Bibring, J. -P.; Gondet, B.; Langevin, Y. +6 more
The OMEGA imaging spectrometer aboard Mars Express has been used to study the evolution of the CO abundance over the Hellas basin, as a function of the seasonal cycle. In spite of significant uncertainties, due to the low intensity of the (2-0) CO band at 2.3 µm, these data allow to search for spatial variations over Hellas, where the surfac…
Absolute motions of globular clusters. II. HST astrometry and VLT radial velocities in NGC 6397
Anderson, J.; Milone, A. P.; Bedin, L. R. +5 more
In this paper we present a new, accurate determination of the three components of the absolute space velocity of the Galactic globular cluster NGC 6397 (l≃338°, b≃-12°). We used three HST/WFPC2 fields with multi-epoch observations to obtain astrometric measurements of objects in three different fields in this cluster. The identification of 33 back…
Stellar archaeology: the evolving spectrum of FG Sagittae
Jeffery, C. S.; Schönberner, D.
Over an interval of 120 years, the extraordinary object
Multi-wavelength afterglow observations of the high redshift GRB 050730
McBreen, S.; Bremer, M.; Tanvir, N. +22 more
Context: .GRB 050730 is a long duration high-redshift burst (z=3.967) that was discovered by Swift. The afterglow shows variability and was well monitored over a wide wavelength range. We present comprehensive temporal and spectral analysis of the afterglow of GRB 050730 including observations covering the wavelength range from the millimeter to X…
Dust-scattered X-ray halos around gamma-ray bursts: GRB 031203 revisited and the new case of GRB 050713A
Tiengo, A.; Mereghetti, S.
Scattering by interstellar dust grains can produce time variable X-ray halos around gamma-ray bursts (GRB). In particular, an X-ray expanding ring is expected when a short pulse of X-ray radiation is scattered by a narrow layer of dust in our Galaxy. We present a new method for detecting and analyzing dust-scattering expanding rings around gamma-r…
On the horizontal branch of the galactic globular cluster NGC 2808
Zoccali, M.; Bono, G.; Cassisi, S. +3 more
We present new UV (F218W) data for stars in the central region of the Galactic globular cluster NGC 2808, collected with the WFPC2 camera on board the Hubble Space Telescope. These data together with F439W and F555W-band data and previous ground-based observations provide a multifrequency coverage of the cluster stellar population extending up to …
Probing the proper motion of the central compact object in Puppis-A with the Chandra high resolution camera
Hui, C. Y.; Becker, W.
By making use of the sub-arcsecond angular resolution of the High Resolution Camera (HRC-I) aboard the Chandra X-ray satellite we have examined the central compact object RX J0822-4300 in the supernova remnant Puppis-A for a possible proper motion. Using data which span an epoch of 1952 days we found the position of RX J0822-4300 different by 0.57…