Search Publications
Radio occultation measurements and MGCM simulations of Kelvin waves on Mars
Pätzold, M.; Wilson, R. J.; Hinson, D. P. +3 more
We have derived new results concerning thermal tides on Mars from a combination of radio occultation measurements and numerical simulations by a Mars General Circulation Model (MGCM). This investigation exploits a set of concurrent observations by Mars Express (MEX) and Mars Global Surveyor (MGS) in mid-2004, when the season on Mars was midspring …
PFS/MEX observations of the condensing CO 2 south polar cap of Mars
Forget, F.; Grassi, D.; Formisano, V. +3 more
The condensing CO 2 south polar cap of Mars and the mechanisms of the CO 2 ice accumulation have been studied through the analysis of spectra acquired by the Planetary Fourier Spectrometer (PFS) during the first two years of ESA's Mars Express (MEX) mission. This dataset spans more than half a martian year, from Ls∼330° to Ls…
Disintegration of Magnetic Flux in Decaying Sunspots as Observed with the Hinode SOT
Kubo, M.; Lites, B. W.; Ichimoto, K. +8 more
Continuous observations of sunspot penumbrae with the Solar Optical Telescope aboard Hinode clearly show that the outer boundary of the penumbra fluctuates around its averaged position. The penumbral outer boundary moves inward when granules appear in the outer penumbra. We discover that such granules appear one after another while moving magnetic…
High-resolution Dione atlas derived from Cassini-ISS images
Scholten, F.; Matz, K. -D.; Neukum, G. +7 more
The Cassini imaging science subsystem (ISS) acquired 449 high-resolution images (<800 m/pixel) during one close flyby of Dione in 2005 and three non-targeted flybys in 2004, 2006, and 2007. We combined these images with lower-resolution Cassini images and one other taken by Voyager cameras to produce a high-resolution semi-controlled mosaic of …
Understanding the Relations between QSOs and Their Host Galaxies from Combined HST Imaging and VLT Spectroscopy
Magain, P.; Courbin, F.; Hutsemékers, D. +2 more
The host galaxies of six nearby QSOs are studied on the basis of high-resolution HST optical images and spatially resolved VLT slit spectra. The gas ionization and velocity are mapped as a function of the distance to the central QSO. In the majority of the cases, the QSO significantly contributes to the gas ionization in its whole host galaxy, and…
Heavy absorption and soft X-ray emission lines in the XMM-Newton spectrum of the type 2 radio-loud quasar 3C 234
Fiore, F.; Bianchi, S.; Guainazzi, M. +4 more
Aims:We report results on a 40 ks XMM-Newton observation of the type 2 quasar 3C 234. Optical spectropolarimetric data have demonstrated the presence of a hidden broad-line region in this powerful (MV ≤ -24.2 after reddening and starlight correction) narrow-line FRII radio galaxy. Our analysis is aimed at investigating the X-ray spectra…
A solar burst with a spectral component observed only above 100 GHz during an M class flare
Mandrini, C. H.; Giménez de Castro, C. G.; Cristiani, G. +4 more
Context: Since the installation of submillimeter solar radio telescopes, a new spectral burst component was discovered at frequencies above 100 GHz, creating the THz burst category. In all the reported cases, the events were X-class flares and the THz component was increasing.
Aims: We report for the first time an M class flare that shows a di…
Interstellar Krypton Abundances: The Detection of Kiloparsec-scale Differences in Galactic Nucleosynthetic History
Sofia, Ulysses J.; Meyer, David M.; Cartledge, Stefan I. B. +2 more
We present an analysis of Kr I λ1236 line measurements from 50 sight lines in the Hubble Space Telescope Space Telescope Imaging Spectrograph and Goddard High Resolution Spectrograph data archives that have sufficiently high resolution and signal-to-noise ratio to permit reliable krypton-to-hydrogen abundance ratio determinations. The distribution…
Follow-up observations of binary ultra-cool dwarfs
Martín, E. L.; Huélamo, N.; Bouy, H. +12 more
Context: Astrometric observations of resolved binaries provide estimates of orbital periods and will eventually lead to measurement of dynamical masses. Only a few very low mass star and brown dwarf masses have been measured to date, and the mass-luminosity relation still needs to be calibrated.
Aims: We have monitored 14 very low mass multipl…
Discovery of ultra-compact nuclear rings in three spiral galaxies
Knapen, J. H.; Comerón, S.; Beckman, J. E. +1 more
Ring-shaped morphologies of nuclear star-forming regions within the central 40{-}200 pc of disk galaxies have been barely resolved so far in three composite Sy 2 nuclei, the Sy 2 Circinus galaxy and in three non-AGN galaxies. Such morphologies resemble those of the standard 1 kpc-size nuclear rings that lie in the inner Lindblad resonance regions …