Search Publications
Transient plasma injections in the dayside magnetosphere: one-to-one correlated observations by Cluster and SuperDARN
Dunlop, M.; Bosqued, J.; Marchaudon, A. +6 more
. Conjunctions in the cusp between the four Cluster spacecraft and SuperDARN ground-based radars offer unique opportunities to compare the signatures of transient plasma injections simultaneously in the high-altitude dayside magnetosphere and in the ionosphere. We report here on such observations on 17 March 2001, when the IMF initially northward …
The origin of the slow solar wind in coronal streamers
Ofman, L.
The highly variable slow solar wind has been associated with low-latitude regions of the heliosphere most clearly by the Ulysses spacecraft. Although, it is evident today that the slow solar wind originates in coronal helmet streamers, the mechanism of the slow solar wind acceleration, and the origin of the variability are still being debated. The…
Axisymmetric dynamical models for SAURON and OASIS observations of NGC3377
Copin, Y.; Emsellem, E.; Cretton, N.
We present a unique set of nested stellar kinematical maps of NGC3377 obtained with the integral-field spectrographs OASIS and SAURON . We then construct general axisymmetric dynamical models for this galaxy, based on the Schwarzschild numerical orbit superposition technique applied to these complementary measurements. We show how these two datase…
Seasonal change in Titan's haze 1992-2002 from Hubble Space Telescope observations
Lorenz, Ralph D.; Lemmon, Mark T.; Smith, Peter H.
Images from the Hubble Space Telescope (HST) document the seasonal migration of haze in Titan's atmosphere. Image profiles show darkening of the north relative to the south at 439 nm (blue) but no change at 619 nm. The limb profile at 889 nm has inverted, becoming north-bright, a variation consistent with haze transport towards the winter hemisphe…
Low Atmosphere Reconnections Associated with An Eruptive Solar Flare
Moon, Y. -J.; Wang, Haimin; Chae, Jongchul +3 more
Pox 186: An ultracompact galaxy with dominant ionized gas emission
Izotov, Y. I.; Papaderos, P.; Guseva, N. G. +2 more
We present a ground-based optical spectroscopic and HST U, V, I photometric study of the blue compact dwarf (BCD) galaxy Pox 186. It is found that the emission of the low-surface brightness (LSB) component in Pox 186 at radii ⪉3 arcsec (⪉270 pc in linear scale) is mainly gaseous in origin. We detect Hα emission out to radii as large as 6 arcsec. A…
Arakelian 564: an XMM-Newton view
Brandt, W. N.; Fabian, A. C.; Boller, Th. +2 more
We report on two XMM-Newton observations of the bright narrow-line Seyfert 1 galaxy Ark 564 taken 1 yr apart (2000 June and 2001 June). The 0.6-10 keV continuum is well described by a soft blackbody component (kT~ 140-150 eV) plus a steep power law (Γ~ 2.50-2.55). No significant spectral changes are observed between the two observations, although …
Asiago eclipsing binaries program. I. V432 Aurigae
Munari, U.; Zwitter, T.; Sordo, R. +4 more
The orbit and physical parameters of the previously unsolved eclipsing binary V432 Aur, discovered by Hipparcos, have been derived with errors better than 1% from extensive Echelle spectroscopy and B, V photometry. Synthetic spectral analysis of both components has been performed, yielding Teff and log g in close agreement with the orbi…
INTEGRAL Field Spectroscopy of the Extended Ionized Gas in Arp 220
Arribas, Santiago; Colina, Luis; Clements, David
Integral field optical spectroscopy with the INTEGRAL system has been used to investigate for the first time the two-dimensional kinematic and ionization properties of the extended, warm, ionized gas in Arp 220 over an area of 75.0"×40.0" (i.e., 28×15 kpc). The structure of the ionized gas is divided into well-identified regions associated with th…
The morphology of cometary X-ray emission
Dennerl, K.; Wegmann, R.; Lisse, C. M.
X-ray emission from comets is generated by charge exchange of heavy solar wind ions in a high ionization state with the neutral particles of the cometary coma. We use model calculations and theoretical considerations to study the morphology of the emission. The emission is located in a bowl-shaped region on the subsolar side of the nucleus. We der…