Search Publications
Stellar populations in the CFHTLS. I. New constraints on the IMF at low mass
Schultheis, M.; Bertin, E.; McCracken, H. J. +4 more
We present a stellar populations analysis of the first release of the CFHTLS (Canada-France-Hawai Telescope Legacy Survey) data. A detailed comparison between the Besançon model of the Galaxy and the first data release of the CFHTLS-Deep survey is performed by implementing the MEGACAM photometric system in this model using stellar atmosphere model…
New nearby active galactic nuclei among INTEGRAL and RXTE X-ray sources
Bikmaev, I. F.; Sunyaev, R. A.; Revnivtsev, M. G. +1 more
We present the first results of a campaign to optically identify X-ray sources discovered in the all-sky surveys of the RXTE and INTEGRAL observatories. Six newly discovered sources proved to be hitherto unknown nearby active galactic nuclei (z < 0.1). Spectrophotometric studies of these sources were performed with the Russian-Turkish 1.5-m tel…
Interaction of moist convection with zonal jets on Jupiter and Saturn
Ingersoll, Andrew P.; Li, Liming; Huang, Xianglei
Observations suggest that moist convection plays an important role in the large-scale dynamics of Jupiter's and Saturn's atmospheres. Here we use a reduced-gravity quasigeostrophic model, with a parameterization of moist convection that is based on observations, to study the interaction between moist convection and zonal jets on Jupiter and Saturn…
High-Resolution Infrared Imaging of Herschel 36 SE: A Showcase for the Influence of Massive Stars in Cluster Environments
Pascucci, I.; Stecklum, B.; Henning, Th. +4 more
We present high-resolution infrared imaging of the massive star-forming region around the O star Herschel 36. Special emphasis is given to a compact infrared source at 0.25" southeast of the star. The infrared source, hereafter Her 36 SE, is extended in the broadband images but features spatially unresolved Brγ line emission. The line-emission sou…
The structure and X-ray radiation spectra of illuminated accretion disks in AGN. III. Modeling fractional variability
Ponti, G.; Różańska, A.; Dovčiak, M. +5 more
Context: .Random magnetic flares above the accretion disks of Active Galactic Nuclei can account for the production of the primary radiation and for the rapid X-ray variability that have been frequently observed in these objects. The primary component is partly reprocessed in the disk atmosphere, forming a hot spot underneath the flare source and …
The white dwarf in AE Aqr brakes harder
Mauche, Christopher W.
Taking advantage of the very precise de Jager et al. optical white dwarf orbit and spin ephemerides; ASCA, XMM-Newton and Chandra X-ray observations spread over 10yr and a cumulative 27-yr baseline, we have found that in recent years the white dwarf in AE Aqr is spinning down at a rate that is slightly faster than predicted by the de Jager et al. …
A Snapshot Survey for Gravitational Lenses among z>=4.0 Quasars. II. Constraints on the 4.0<z<5.4 Quasar Population
Strauss, Michael A.; Brinkmann, J.; Fan, Xiaohui +7 more
We report on i-band snapshot observations of 157 Sloan Digital Sky Survey quasars at 4.0<z<5.4 using the Advanced Camera for Surveys on the Hubble Space Telescope (HST) to search for evidence of gravitational lensing of these sources. None of the quasars appear to be strongly lensed and multiply imaged at the angular resolution (~0.1") and s…
A detailed observation of a LMC supernova remnant DEM L241 with XMM-Newton
Koyama, K.; Mori, K.; Bamba, A. +2 more
We report on an XMM-Newton observation of the supernova remnant (SNR)
Microphysics of Magnetic Reconnection
Retinò, Alessandro; Vaivads, Andris; André, Mats
Magnetic reconnection is a universal phenomenon where energy is efficiently converted from the magnetic field to charged particles as a result of global magnetic topology changes during which earlier separated plasma regions become magnetically connected. While the reconnection affects large volumes in space most of the topology changes and of the…
Topographic modeling of Phoebe using Cassini images
Porco, Carolyn C.; Neukum, Gerhard; Roatsch, Thomas +2 more
High-resolution Cassini stereo images of Saturn's moon Phoebe have been used to derive a regional digital terrain model (DTM) and an orthoimage mosaic of the surface. For DTM-control a network of 130 points measured in 14 images (70-390 m/pixel resolution) was established which was simultaneously used to determine the orientation of the spin-axis.…