Search Publications
Initial Helioseismic Observations by Hinode/SOT
Tsuneta, Saku; Shimizu, Toshifumi; Zhao, Junwei +12 more
Results from initial helioseismic observations by the Solar Optical Telescope on-board Hinode are reported. It has been demonstrated that intensity oscillation data from the Broadband Filter Imager can be used for various helioseismic analyses. The k - ω power spectra, as well as the corresponding time-distance cross-correlation function, which pr…
Compton Telescope with a Coded Aperture Mask: Imaging with the INTEGRAL/IBIS Compton Mode
Laurent, P.; Lebrun, F.; Limousin, O. +1 more
Compton telescopes provide good sensitivity over a wide field of view in the difficult energy range from a few hundred keV to several MeV. Their angular resolution is, however, poor and strongly energy dependent. We present a novel experimental design associating a coded mask and a Compton detection unit to overcome these pitfalls. It maintains th…
Triggering Mechanism for the Filament Eruption on 2005 September 13 in NOAA Active Region 10808
Shibata, Kazunari; Okamoto, Takenori J.; Yokoyama, Takaaki +3 more
On 2005 September 13 a filament eruption accompanied by a halo coronal mass ejection (CME) occurred in the most flare-productive active region, NOAA 10808, in solar cycle 23. Using multiwavelength observations before the filament eruption on September 13, we investigate the processes leading to the catastrophic eruption. We find that the filament …
Spontaneous Generation of Self-Organized Solitary Wave Structures at Earth's Magnetopause
Davies, J. A.; Vaivads, A.; Dunlop, M. W. +5 more
Spontaneous formation of solitary wave structures has been observed in Earth’s magnetopause, and is shown to be caused by the breakup of a zonal flow by the action of drift wave turbulence. Here we show matched observations and modeling of coherent, large-scale solitary electrostatic structures, generated during the interaction of short-scale drif…
Observation of Interactions and Eruptions of Two Filaments
Zhang, Hongqi; Liu, Yu; Wang, Haimin +4 more
We present new observations of the interactions of two close, but distinct, Hα filaments and their successive eruptions on 5 November 1998. The magnetic fields of the filaments are both of the sinistral type. The interactions between the two filaments were initiated mainly by an active filament of one of them. Before the filament eruptions, two da…
Properties of the dust cloud caused by the Deep Impact experiment
Jorda, L.; Lara, L. M.; Lamy, P. +7 more
We present an analysis of the observations of the Deep Impact event performed by the OSIRIS narrow angle camera aboard the Rosetta spacecraft over two weeks, in an effort to characterize the cometary dust grains ejected from the nucleus of Comet 9P/Tempel 1. We adopt a Monte Carlo approach to generate calibrated synthetic images, and a linear comb…
Ionic Charge States of Solar Energetic Particles: A Clue to the Source
Klecker, B.; Möbius, E.; Popecki, M. A.
The ionic charge of solar energetic particles (SEP) as observed in interplanetary space is an important parameter for the diagnostic of the plasma conditions at the source region and provides fundamental information about the acceleration and propagation processes at the Sun and in interplanetary space. In this paper we review the new measurements…
Detection of the first thermonuclear X-ray burst from AX J1754.2-2754
Grebenev, S. A.; Chelovekov, I. V.
When analyzing the archival data of the INTEGRAL observatory, we detected an intense X-ray burst recorded on April 16, 2005, by the JEM-X and IBIS/ISGRI telescopes from the weak and poorly studied source AX J1754.2-2754. Analysis of its time profiles and spectra allows this event to be attributed to type I X-ray bursts associated with thermonuclea…
Helioseismic Test of Nonhomologous Solar Radius Changes with the 11 Year Activity Cycle
Kosovichev, A. G.; Lefebvre, S.; Rozelot, J. P.
Recent models of variations of the Sun's structure with the 11 year activity cycle by Sofia et al. predict strong nonhomologous changes of the radius of subsurface layers, due to subsurface magnetic fields and field-modulated turbulence. According to their best model, the changes of the surface radius may be 1000 times larger than those at the dep…
Suzaku Observations of HESS J1616-508: Evidence for a Dark Particle Accelerator
Mori, Hideyuki; Porter, Frederick S.; Kokubun, Motohide +15 more
We observed the bright unidentified TeV γ-ray source HESS J1616-508 with the X-ray Imaging Spectrometers onboard the Suzaku satellite. No X-ray counterpart was found to a limiting flux of 3.1 × 10-13 erg s-1 cm-2 in the 2-10keV band, which is some 60-times below the γ-ray flux in the 1-10TeV band. This object is br…