Search Publications
Global solar Doppler velocity determination with the GOLF/SoHO instrument
Jiménez-Reyes, S. J.; García, R. A.; Pallé, P. L. +10 more
The Global Oscillation at Low Frequencies (GOLF) experiment is a resonant scattering spectrophotometer on board the Solar and Heliospheric Observatory (SoHO) mission, originally designed to measure the disk-integrated solar oscillations of the Sun. This instrument was designed in a relative photometric mode involving both wings of the neutral sodi…
Gamma-ray continuum emission from the inner Galactic region as observed with INTEGRAL/SPI
Strong, A. W.; Bouchet, L.; Terrier, R. +5 more
The diffuse continuum emission from the Galactic plane in the energy range 18-1000 keV has been studied using 16 Ms of data from the SPI instrument on INTEGRAL. With such an exposure we can exploit the imaging properties of SPI to achieve a good separation of point sources from the various diffuse components. Using a candidate-source catalogue der…
Evolution and rotation of large-scale photospheric magnetic fields of the Sun during cycles 21-23. Periodicities, north-south asymmetries and r-mode signatures
Stenflo, J. O.; Berdyugina, S. V.; Knaack, R.
We present the results of an extensive time series analysis of longitudinally-averaged synoptic maps, recorded at the National Solar Observatory (NSO/Kitt Peak) from 1975 to 2003, and provide evidence for a multitude of quasi-periodic oscillations in the photospheric magnetic field of the Sun. In the low frequency range, we have located the source…
The evolution of early-type galaxies at z ∼ 1 from the K20 survey
Cimatti, A.; Daddi, E.; di Serego Alighieri, S. +10 more
We have performed VLT spectroscopy of an almost complete sample of 18 early-type galaxies with 0.88≤ z≤ 1.3 plus two at z=0.67, selected from the K20 survey, and derived the velocity dispersion for 15+2 of them. By combining these data with HST and VLT images, we study the Fundamental Plane (FP), the Faber-Jackson and the Kormendy relations at z ∼…
Spatially resolved microwave pulsations of a flare loop
Melnikov, V. F.; Nakariakov, V. M.; Shibasaki, K. +1 more
A microwave burst with quasi-periodic pulsations was studied with high spatial resolution using observations with the Nobeyama Radioheliograph (NoRH). We found that the time profiles of the microwave emission at 17 and 34 GHz exhibit quasi-periodic (with two well defined periods P_1= 14-17 s and P_2= 8-11 s) variations of the intensity at differen…
INTEGRAL and RXTE observations of accreting millisecond pulsar IGR J00291+5934 in outburst
Goldoni, P.; Stella, L.; Kuiper, L. +7 more
Simultaneous observations of the accretion-powered millisecond pulsar IGR J00291+5934 by the International Gamma-Ray Astrophysics Laboratory and Rossi X-ray Timing Explorer during the 2004 December outburst are analysed. The average spectrum is well described by thermal Comptonization with an electron temperature of 50 keV and Thomson optical dept…
A model of the Alfvén speed in the solar corona
Mann, G.; Warmuth, A.
We present an analytic model of the Alfvén speed vA in the solar corona. The coronal magnetic field is modeled by a radial component representing the global field and by a dipole representing an active region. The free parameters of the model are constrained by actual observations of solar magnetic fields and coronal electron densities.…
Near-infrared (0.8-4.0 µm) spectroscopy of Mimas, Enceladus, Tethys, and Rhea
Brown, R. H.; Emery, J. P.; Burr, D. M. +2 more
Spectral measurements from the ground in the time leading up to the Cassini mission at Saturn provide important context for the interpretation of the forthcoming spacecraft data. Whereas ground-based observations cannot begin to approach the spatial scales Cassini will achieve, they do possess the benefits of better spectral resolution, a broader …
X-rays from accretion shocks in T Tauri stars: The case of BP Tau
Schmitt, J. H. M. M.; Ness, J. -U.; Robrade, J. +2 more
We present an XMM-Newton observation of the classical T Tauri star BP Tau. In the XMM-Newton RGS spectrum the O vii triplet is clearly detected with a very weak forbidden line indicating high plasma densities and/or a high UV flux environment. At the same time concurrent UV data point to a small hot spot filling factor suggesting an accretion funn…
An XMM-Newton view of the cluster of galaxies Abell 85
Forman, W.; Durret, F.; Lima Neto, G. B.
We have observed the cluster of galaxies Abell 85 with XMM-Newton. These data have allowed us in a previous paper to confirm the existence of the extended 4 Mpc filament detected by the ROSAT PSPC in the neighbourhood of this cluster, and to determine an X-ray temperature of about ~ 2 keV. We now present a thorough analysis of the properties of th…