Search Publications
Investigation of mass flows in the transition region and corona in a three-dimensional numerical model approach
Peter, H.; Zacharias, P.; Bingert, S.
Context. The origin of solar transition region redshifts is not completely understood. Current research is addressing this issue by investigating three-dimensional magneto-hydrodynamic models that extend from the photosphere to the corona.
Aims: By studying the average properties of emission line profiles synthesized from the simulation runs …
The energetics of giant radio galaxy lobes from inverse Compton scattering observations
Colafrancesco, S.; Marchegiani, P.
Context. Giant radio galaxy (GRG) lobes are excellent laboratories for studying the evolution of the particle and magnetic field energetics and the past activity of radiogalaxy jets, as indicated by recent results of X-ray observations with Suzaku. However, these results are based on assumptions of the shape and extension of the GRG lobe electron …
Mid-infrared interferometry of the massive young stellar object NGC 2264 IRS 1
Grellmann, R.; Weigelt, G.; Preibisch, T. +3 more
Context. The optically invisible infrared-source NGC 2264 IRS 1 lying north of the Cone Nebula is thought to be a massive young stellar object (~10 M⊙). Although strong infrared excess clearly shows that the central object is surrounded by large amounts of circumstellar material, no information about the spatial distribution of this cir…
Optical dropout galaxies lensed by the cluster A2667
Schaerer, D.; Laporte, N.; Pelló, R. +8 more
Context. We investigate the nature and the physical properties of ten z, Y, and J-dropout galaxies selected in the field of the lensing cluster A2667.
Aims: This cluster is part of our project aimed at obtaining deep photometry at ~0.8-2.5 microns with ESO/VLT HAWK-I and FORS2 on a representative sample of lensing clusters extracted from our …
Monitoring the solar UV irradiance spectrum from the observation of a few passbands
Kretzschmar, M.; Dudok de Wit, T.; Cessateur, G. +3 more
Context. The solar irradiance in the UV is a key ingredient in space weather applications; however, because of the lack of continuous and long-term observations, various indices are still used today as surrogates for the solar spectral irradiance.
Aims: As an alternative to current spectrometers we use a few radiometers with properly chosen p…
Lunar mare single-scattering, porosity, and surface-roughness properties with SMART-1 AMIE
Koschny, D.; Foing, B.; Muinonen, K. +8 more
A novel shadowing and coherent-backscattering model is utilized in the analysis of the single-scattering albedos and phase functions, local surface roughness, and regolith porosity of specific lunar mare regions imaged by the AMIE camera (Advanced Moon micro-Imager Experiment) onboard ESA SMART-1 mission. Shadowing due to the regolith particles is…
Mode visibilities in radial velocity and photometric Sun-as-a-star helioseismic observations
García, R. A.; Ballot, J.; Salabert, D.
We analyze more than 5000 days of high-quality Sun-as-a-star, radial velocity GOLF and photometric VIRGO/SPM helioseismic observations to extract precise estimates of the visibilities of the low-degree p modes and the m-height ratios of the l = 2 and 3 multiplets in the solar acoustic spectrum. The mode visibilities are shown to be larger during t…
Nebular and global properties of the gravitationally lensed galaxy "the 8 o'clock arc"
Schaerer, D.; Dessauges-Zavadsky, M.; Richard, J. +2 more
We present the analysis of new near-infrared, intermediate-resolution spectra of the gravitationally lensed galaxy "the 8 o'clock arc" at zsys = 2.7350 obtained with the X-shooter spectrograph on the Very Large Telescope. These rest-frame optical data, combined with Hubble and Spitzer Space Telescopes images, provide very valuable infor…
Detection of a large massive circumstellar disk around a high-mass young stellar object in the Carina Nebula
Preibisch, T.; Zinnecker, H.; McCaughrean, M. J. +5 more
Context. The characterization of circumstellar disks around young stellar objects can provide important information about the process of star formation and the possible formation of planetary systems.
Aims: We investigate the spatial structure and the spectral energy distribution of a newly discovered edge-on circumstellar disk around an opti…
X-ray observations of sub-mm LABOCA galaxies in the eCDFS
Comastri, A.; Georgantopoulos, I.; Rovilos, E.
We explore the X-ray properties of the 126 sub-mm galaxies (SMGs) of the LABOCA survey in the CDFS and the eCDFS regions. SMGs are believed to experience massive episodes of star formation. Our goal is to examine whether star formation coexists with AGN activity, determine the fraction of highly obscured AGN, and finally to obtain an idea of the d…