Search Publications
XMM-Newton observations of PSR B1259-63 near the 2004 periastron passage
Rodriguez, J.; Lutovinov, A.; Johnston, S. +2 more
PSR B1259-63 is in a highly eccentric 3.4-yr orbit with a Be star and crosses the Be star disc twice per orbit, just prior to and just after periastron. Unpulsed radio, X-ray and gamma-ray emission observed from the binary system is thought to be due to the collision of pulsar wind with the wind of Be star. We present here the results of new XMM-N…
Modification of the dichotomy boundary on Mars by Amazonian mid-latitude regional glaciation
Head, James W.; Neukum, Gerhard; Marchant, David R. +1 more
Restoration of the dichotomy boundary to its original position to assess its origin requires a thorough knowledge of processes responsible for its degradation and retreat. The unique fretted terrain, located along the Deuteronilus-Protonilus Mensae northern mid-latitude portion of the boundary, has been long held to provide clues to dichotomy degr…
Loss of hydrogen and oxygen from the upper atmosphere of Venus
Barabash, S.; Gunell, H.; Lammer, H. +9 more
Atmospheric escape from the upper atmosphere of Venus is mainly influenced by the loss of hydrogen and oxygen caused by the interaction of solar radiation and particle flux with the unprotected planetary environment. Because one main aim of the ASPERA-4 particle/plasma and VEX-MAG magnetic field experiments on board of ESA's forthcoming Venus Expr…
LINER-like Extended Nebulae in ULIRGs: Shocks Generated by Merger-Induced Flows
Colina, L.; Monreal-Ibero, A.; Arribas, S.
In this work we studied the two-dimensional ionization structure of the circumnuclear and extranuclear regions in a sample of six low-z ultraluminous infrared galaxies using integral field spectroscopy. The ionization conditions in the extranuclear regions of these galaxies (~5-15 kpc) are typical of LINERs as obtained from the Veilleux-Osterbrock…
The evolution of the cluster X-ray scaling relations in the Wide Angle ROSAT Pointed Survey sample at 0.6 < z < 1.0
Maughan, B. J.; Ebeling, H.; Jones, L. R. +1 more
The X-ray properties of a sample of 11 high-redshift (0.6 < z < 1.0) clusters observed with Chandra and/or XMM-Newton are used to investigate the evolution of the cluster scaling relations. The observed evolution in the normalization of the L-T, M-T, Mg-T and M-L relations is consistent with simple self-similar predictions, in whi…
The Homogeneity of Interstellar Elemental Abundances in the Galactic Disk
Sofia, Ulysses J.; Meyer, David M.; Cartledge, Stefan I. B. +1 more
We present interstellar elemental abundance measurements derived from Space Telescope Imaging Spectrograph echelle observations of 47 sight lines extending up to 6.5 kpc through the Galactic disk. These paths probe a variety of interstellar environments, covering ranges of nearly 4 orders of magnitude in molecular hydrogen fraction f(H2…
Mass composition of the escaping plasma at Mars
Coates, A. J.; Kallio, E.; Fedorov, A. +44 more
Data from the Ion Mass Analyzer (IMA) sensor of the ASPERA-3 instrument suite on Mars Express have been analyzed to determine the mass composition of the escaping ion species at Mars. We have examined 77 different ion-beam events and we present the results in terms of flux ratios between the following ion species: CO +2/O
IGR J17544-2619 : a new supergiant fast X-ray transient revealed by optical/infrared observations
Chaty, S.; Negueruela, I.; Pellizza, L. J.
One of the most recent discoveries of the INTEGRAL observatory is the existence of a previously unknown population of X-ray sources in the inner arms of the Galaxy.
INTEGRAL/RXTE high-energy observation of a state transition of GX 339-4
Belloni, T.; Miller, J. M.; Homan, J. +7 more
On 2004 August 15, we observed a fast (shorter than 10 h) state transition in the bright black hole transient GX 339-4 simultaneously with Rossi X-Ray Timing Explorer (RXTE) and INTEGRAL. This transition was evident both in timing and spectral properties. Combining the data from the Proportional Counter Array (PCA), the High-Energy X-ray Timing Ex…
The ACS Virgo Cluster Survey. XI. The Nature of Diffuse Star Clusters in Early-Type Galaxies
Jordán, Andrés; Tonry, John L.; Côté, Patrick +7 more
We use HST ACS imaging of 100 early-type galaxies in the ACS Virgo Cluster Survey to investigate the nature of diffuse star clusters (DSCs). Compared to globular clusters (GCs), these star clusters have low luminosities (MV>-8) and a broad distribution of sizes (3<rh<30 pc), but they are principally characterized by …