Search Publications
Hard X-Ray Emission of the Microquasar GX 339-4 in the Low/Hard State
Rodriguez, J.; Malzac, J.; Joinet, A. +4 more
We present the analysis of the high-energy emission of the Galactic black hole binary GX 339-4 in a low/hard state at the beginning of its 2004 outburst. The data from 273 ks of INTEGRAL observations, spread over 4 weeks, are analyzed, along with the existing simultaneous RXTE HEXTE and PCA data. During this period, the flux increases by a factor …
The Plasma Structure of the Cygnus Loop from the Northeastern Rim to the Southwestern Rim
Miller, Eric D.; Katsuda, Satoru; Tsunemi, Hiroshi +1 more
The Cygnus Loop was observed from the northeast to the southwest with XMM-Newton. We divided the observed region into two parts, the north and the south path, and studied the X-ray spectra along the two. The spectra can be well fitted either by a one-component nonequilibrium ionization (NEI) model or by a two-component NEI model. The rim regions c…
The Cause of Photospheric and Helioseismic Responses to Solar Flares: High-Energy Electrons or Protons?
Kosovichev, A. G.
Analysis of the hydrodynamic and helioseismic effects in the photosphere during the solar flare of 2002 July 23, observed by MDI/SOHO, and high-energy images from RHESSI show that these effects are closely associated with sources of the hard X-ray emission but that no such effects existed in the centroid region of the flare's gamma-ray emission. T…
A Shell of Thermal X-Ray Emission Surrounding the Young Crab-like Remnant 3C 58
Gotthelf, E. V.; Helfand, D. J.; Newburgh, L.
Deep X-ray imaging spectroscopy of the bright pulsar wind nebula 3C 58 confirms the existence of an embedded thermal X-ray shell surrounding the pulsar PSR J0205+6449. Radially resolved spectra obtained with the XMM-Newton telescope are well characterized by a power-law model with the addition of a soft thermal emission component in varying propor…
On the co-existence of chemically peculiar Bp stars, slowly pulsating B stars and constant B stars in the same part of the HR diagram
Aerts, C.; Briquet, M.; De Cat, P. +3 more
Aims: In order to better model massive B-type stars, we need to understand the physical processes taking place in slowly pulsating B (SPB) stars, chemically peculiar Bp stars, and non-pulsating normal B stars co-existing in the same part of the H-R diagram.
Methods: We carry out a comparative study between samples of confirmed and well-studied…
Distances to Populous Clusters in the Large Magellanic Cloud via the K-band Luminosity of the Red Clump
Sarajedini, Ata; Grocholski, Aaron J.; Tiede, Glenn P. +2 more
We present results from a study of the distances and distribution of a sample of intermediate-age clusters in the Large Magellanic Cloud (LMC). Using deep near-infrared photometry obtained with ISPI on the CTIO 4 m, we have measured the apparent K-band magnitude of the core helium-burning red clump stars in 17 LMC clusters. We combine cluster ages…
SD2 How To Sample A Comet
Olivieri, A.; Espinasse, S.; Finzi, A. Ercoli +6 more
SD2 (Sampler, Drill and Distribution System), is one of the instruments onboard the lander Philae of the Rosetta mission. This system is of primary importance for the lander mission since it is in charge to collect comet's soil samples at different depths and to distribute them to different instruments for analysis. SD2 has to meet very stringent …
Cluster observations in the inner magnetosphere during the 18 April 2002 sawtooth event: Dipolarization and injection at r = 4.6 RE
Lucek, E. A.; Frey, H. U.; Lui, A. T. Y. +9 more
The present study examines a sawtooth injection event that took place around 0800 UT on 18 April 2002 when the Cluster spacecraft were located in the inner magnetosphere in the premidnight sector. In association with this injection, Cluster, at a radial distance of 4.6 R E , observed that the local magnetic field became more dipolar an…
The Planet Host Star γ Cephei: Physical Properties, the Binary Orbit, and the Mass of the Substellar Companion
Torres, Guillermo
The bright, K1 III-IV star γ Cep has been reported previously to have a possibly substellar companion in a ~2.5 yr orbit, as well as an unseen stellar companion at a larger separation. We determine for the first time the three-dimensional orbit of the latter, accounting also for the perturbation from the closer object. We combine new and existing …
Locating the Two Black Holes in NGC 6240
Canalizo, Gabriela; Max, Claire E.; de Vries, Willem H.
Mergers play an important role in galaxy evolution and are key to understanding the correlation between central black hole mass and host-galaxy properties. We used the new technology of adaptive optics at the Keck II telescope to observe NGC 6240, a merger between two disk galaxies. Our high-resolution near-infrared images, combined with radio and…