Search Publications
A search for the most massive galaxies - III. Global and central structure
Nichol, R. C.; Bernardi, M.; Hyde, J. B. +1 more
We used the Advanced Camera for Surveys onboard the Hubble Space Telescope to obtain high-resolution i-band images of the centres of 23 single galaxies, which were selected because they have Sloan Digital Sky Survey (SDSS) velocity dispersions larger than 350kms-1. The surface brightness profiles of the most luminous of these objects (M…
Asteroid exosphere: A simulation for the ROSETTA flyby targets (2867) Steins and (21) Lutetia
Wurz, P.; Altwegg, K.; Schläppi, B.
Asteroids (2867) Steins and (21) Lutetia are two flyby targets of ESA's cornerstone mission Rosetta. Since Rosetta is a cometary mission, some of the instruments are designed to investigate the surroundings of small bodies. To prepare the operation of these instruments, in our case the ROSINA instrument, for the asteroid flyby's, we adapted a Mont…
Spectral variability of the Martian high latitude surfaces
Bibring, J. -P.; Gondet, B.; Langevin, Y. +3 more
We report the surface distributions of some minerals in the high latitude (>50°) regions of Mars using the OMEGA/MEx observations in the near-infrared wavelength domains (1-2.5 µm). Mafic minerals (pyroxene and olivine) are observed in the low albedo terrains. The identification of these minerals is consistent with the presence of volcani…
Radio Continuum Jet in NGC 7479
Laine, Seppo; Beck, Rainer
The barred galaxy NGC 7479 hosts a remarkable jetlike radio continuum feature: bright, 12 kpc long in projection, and hosting an aligned magnetic field. The degree of polarization is 6%-8% along the jet and remarkably constant, which is consistent with helical field models. The radio brightness of the jet suggests strong interaction with the ISM a…
XMM-Newton observations of ζ Orionis (O9.7 Ib): a collisional ionization equilibrium model
Raassen, A. J. J.; van der Hucht, K. A.; Cassinelli, J. P. +1 more
We present XMM-Newton observations of the O supergiant ζ Orionis (O9.7 Ib). The spectra are rich in emission lines over a wide range of ionization stages. The rgs spectra show for the first time lines of low ion stages such as C VI, N VI, N VII, and O VII. The line profiles are symmetric and rather broad ({{FWHM}}≈ 1500 km s-1) and show…
Cyclostrophic winds from the Visible and Infrared Thermal Imaging Spectrometer temperature sounding: A preliminary analysis
Drossart, P.; Piccioni, G.; Grassi, D. +4 more
Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) onboard the Venus Express spacecraft has been operating since April 2006 providing new observations of the temperature structure of Venus mesosphere (60-95 km). Zonal winds in the middle atmosphere of Venus have been retrieved from VIRTIS temperature profiles using the cyclostrophic approx…
XMM-Newton observations of the Small Magellanic Cloud: Long term evolution of frequently observed Be/X-ray binaries
Haberl, F.; Eger, P.
Aims: To follow the long term evolution of Be/X-ray binaries in the Small Magellanic Cloud (SMC) we analyzed twenty-two XMM-Newton observations towards the calibration target 1E 0102.2-7218 and seven observations towards the neighboring region around the eclipsing binary HD 5980.
Methods: The data from the European Photon Imaging Cameras (EPIC…
X-Ray Sources in the Star-Forming Galaxies NGC 4194 and NGC 7541
Kaaret, Philip; Alonso-Herrero, Almudena
We examine the X-ray point-source population and 2-10 keV luminosity for two galaxies with high star formation rates (SFRs), NGC 4194 and NGC 7541. The X-ray point-source luminosity function (XLF) for these two galaxies is consistent with the XLF found by Grimm et al. for a sample of star-forming galaxies. Combining our results with a sample of ga…
XMM-Newton observations of the Galactic globular clusters NGC 2808 and NGC 4372
Servillat, M.; Webb, N. A.; Barret, D.
Aims:Galactic globular clusters harbour binary systems that are detected as faint X-ray sources. These close binaries are thought to play an important role in the stability of the clusters by liberating energy and delaying the inevitable core collapse of globular clusters. The inventory of close binaries and their identification is therefore essen…
LBT Discovery of a Yellow Supergiant Eclipsing Binary in the Dwarf Galaxy Holmberg IX
Burwitz, V.; Garnavich, P. M.; Kochanek, C. S. +14 more
In a variability survey of M81 using the Large Binocular Telescope we have discovered a peculiar eclipsing binary (MV ~ - 7.1) in the field of the dwarf galaxy Holmberg IX. It has a period of 271 days, and the light curve is well fit by an overcontact model in which both stars are overflowing their Roche lobes. It is composed of two yel…