Search Publications
Chandra Observation of the TeV Source HESS J1834-087
Pavlov, George G.; Kargaltsev, Oleg; Misanovic, Zdenka
Chandra ACIS observed the field of the extended TeV source HESS J1834-087 for 47 ks. A previous XMM-Newton EPIC observation of the same field revealed a point-like source (XMMU J183435.3-084443) and an offset region of faint extended emission. In the low-resolution, binned EPIC images the two appear to be connected. However, the high-resolution Ch…
Lunar X-ray fluorescence observations by the Chandrayaan-1 X-ray Spectrometer (C1XS): Results from the nearside southern highlands
Grande, M.; Alha, L.; Huovelin, J. +19 more
The Chandrayaan-1 X-ray Spectrometer (C1XS) flown on-board the first Indian lunar mission Chandrayaan-1, measured X-ray fluorescence spectra during several episodes of solar flares during its operational period of ∼9 months. The accompanying X-ray Solar Monitor (XSM) provided simultaneous spectra of solar X-rays incident on the Moon which are esse…
Development of parallel electric fields at the plasma sheet boundary layer
Lysak, Robert L.; Song, Yan
Many measurements of auroral particles, in particular recent measurements from the FAST satellite, indicate that the auroral electron distribution is often broad in energy and field-aligned in pitch angle. Such electrons are seen in conjunction with strong kinetic Alfvén waves with small perpendicular wavelength, and so the aurora produced by thes…
Case Study of Four Homologous Large-scale Coronal Waves Observed on 2010 April 28 and 29
Temmer, M.; Nitta, N.; Veronig, A. M. +3 more
On 2010 April 28 and 29, the Solar TErrestrial Relations Observatory B/Extreme Ultraviolet Imager observed four homologous large-scale coronal waves, the so-called EIT-waves, within 8 hr. All waves emerged from the same source active region, were accompanied by weak flares and faint coronal mass ejections, and propagated into the same direction at…
COSMOS weak-lensing constraints on modified gravity
Schrabback, T.; Tereno, I.; Semboloni, E.
The observed acceleration of the universe, explained through dark energy, could alternatively be explained through a modification of gravity that would also induce modifications in the evolution of cosmological perturbations. We use new weak lensing data from the COSMOS survey to test for deviations from general relativity (GR). The departure from…
Merging history of three bimodal clusters
Bourdin, H.; Mars, G.; Benoist, C. +5 more
We present a combined X-ray and optical analysis of three bimodal galaxy clusters selected as merging candidates at z ~ 0.1. These targets are part of MUSIC (MUlti-Wavelength Sample of Interacting Clusters), which is a general project designed to study the physics of merging clusters by means of multi-wavelength observations. Observations include …
Suzaku View of the Swift/BAT Active Galactic Nuclei. III. Application of Numerical Torus Models to Two Nearly Compton Thick Active Galactic Nuclei (NGC 612 and NGC 3081)
Aird, James; Ueda, Yoshihiro; Awaki, Hisamitsu +3 more
The broadband spectra of two Swift/BAT active galactic nuclei (AGNs) obtained from Suzaku follow-up observations are studied: NGC 612 and NGC 3081. Fitting with standard models, we find that both sources show similar spectra characterized by heavy absorption with N H ~= 1024 cm-2, and the fraction of scattered ligh…
Evidence for a current sheet forming in the wake of a coronal mass ejection from multi-viewpoint coronagraph observations
Patsourakos, S.; Vourlidas, A.
Context. Ray-like features observed by coronagraphs in the wake of coronal mass ejections (CMEs) are sometimes interpreted as the white light counterparts of current sheets (CSs) produced by the eruption. The 3D geometry of these ray-like features is largely unknown and its knowledge should clarify their association to the CS and place constraints…
Direct evidence of differences in magnetic rotation rate between Saturn's northern and southern polar regions
Southwood, David
The discovery of a difference in apparent rotation rate between Saturn kilometric radio emission from northern and southern hemispheres leads immediately to the question of whether there is a counterpart detectable in the Saturnian magnetic field. We report direct detection of a difference in the rotating magnetic signal measured by the Cassini sp…
Precise Estimates of the Physical Parameters for the Exoplanet System HD 17156 Enabled by Hubble Space Telescope Fine Guidance Sensor Transit and Asteroseismic Observations
Nelan, Edmund P.; Gilliland, Ronald L.; Christensen-Dalsgaard, Jørgen +6 more
We present observations of three distinct transits of HD 17156b obtained with the Fine Guidance Sensors on board the Hubble Space Telescope. We analyzed both the transit photometry and previously published radial velocities to find the planet-star radius ratio Rp /R sstarf = 0.07454 ± 0.00035, inclination i = 86.49+0.24<…