Search Publications
The X-ray emission from Young Stellar Objects in the ρ Ophiuchi cloud core as seen by XMM-Newton.
Grosso, N.; Montmerle, T.; Ozawa, H.
We observed the main core F of the ρ Ophiuchi cloud, an active star-forming region located at d ∼ 140 pc, using XMM-Newton with an exposure of 33 ks. We detect 87 X-ray sources within the 30 arcmin diameter field-of-view of the EPIC imaging detector array. We cross-correlate the positions of XMM-Newton X-ray sources with previous X-ray, infrared (…
Inferred acoustic rates of solar p modes from several helioseismic instruments
Goupil, M. -J.; Baudin, F.; Chaplin, W. J. +5 more
Acoustic rates of excitation of solar p modes can be estimated from observations in order to place constraints on the modelling of the excitation process and the layers where it occurs in the star. For several reasons (including a poor signal to noise ratio and mode overlap), this estimation is difficult. In this work, we use three completely inde…
A spectroscopic search for the non-nuclear Wolf-Rayet population of the metal-rich spiral galaxy M 83
Schmutz, W.; Crowther, P. A.; Schild, H. +1 more
We present a catalogue of non-nuclear regions containing Wolf-Rayet stars in the metal-rich spiral galaxy M 83 (NGC 5236). From a total of 283 candidate regions identified using He ii λ4686 imaging with VLT-FORS2, Multi Object Spectroscopy of 198 regions was carried out, confirming 132 WR sources. From this sub-sample, an exceptional content of ~1…
A far UV study of interstellar gas towards HD 34078: High excitation H2 and small scale structure
Le Petit, F.; Roueff, E.; Andersson, B. -G. +5 more
To investigate the presence of small scale structure in the spatial distribution of H2 molecules we have undertaken repeated FUSE UV observations of the runaway O9.5V star, HD 34078. In this paper we present five spectra obtained between January 2000 and October 2002. These observations reveal an unexpectedly large amount of highly exci…
Close binary companions of the HAeBe stars LkHα 198, Elias 1, HK Ori and V380 Ori
Duschl, W. J.; Weigelt, G.; Hofmann, K. -H. +5 more
We present diffraction-limited bispectrum speckle interferometry observations of four well-known Herbig Ae/Be (HAeBe) stars,
The onset of solar energetic particle events: prompt release of deka-MeV protons and associated coronal activity
Klein, K. -L.; Posner, A.
Between 1996 and 2002, the COSTEP particle instrument aboard the SoHO mission observed 18 solar energetic particle events where the release times of protons up to 54 MeV could be determined to within an uncertainty of about ten minutes, and where metre wave imaging observations with the Nançay Radioheliograph were available. In six of them the pro…
Discovery and monitoring of the likely IR counterpart of SGR 1806-20 during the 2004 γ-ray burst-active state
Covino, S.; Campana, S.; Götz, D. +9 more
The sky region including the Chandra position of SGR 1806-20 was monitored in the IR band during 2004, following its increased high energy bursting activity. Observations were performed using NAOS-CONICA, the adaptive optics IR camera mounted on Yepun VLT, which provided images of unprecedented quality (FWHM better than 0.1 arcsec). After the 2004…
An optical time delay for the double gravitational lens system FBQ 0951+2635
Lidman, C.; Hjorth, J.; Jakobsson, P. +3 more
We present optical R-band light curves of the double gravitationally lensed quasar FBQ 0951+2635 from observations obtained at the Nordic Optical Telescope between March 1999 and June 2001. A time delay of Δ τ = 16 ± 2 days (1σ) is determined from the light curves. New constraints on the lensing geometry are provided by the position and ellipticit…
INTEGRAL observations of five sources in the Galactic Center region
Sunyaev, R.; Revnivtsev, M.; Lutovinov, A. +1 more
A number of new X-ray sources (IGR J17091-3624, IGR/XTE J17391-3021, IGR J17464-3213 (=XTE J17464-3213 = H 1743-322), IGR J17597-2201, SAX/IGR J18027-2017) have been observed with the INTEGRAL observatory during ultra deep exposure of the Galactic Center region in August-September 2003. Most of them were permanently visible by INTEGRAL at energies…
Time series study of EUV spicules observed by SUMER/SoHO
Doyle, J. G.; Xia, L. D.; Popescu, M. D. +1 more
Here we study the dynamic properties of EUV spicules seen at the solar limb. The selected data were obtained as time series in polar coronal holes by SUMER/SoHO. The short exposure time and the almost fixed position of the spectrometer's slit allow the analysis of spicule properties such as occurrence, lifetime and Doppler velocity. Our data revea…