Search Publications
Discoveries of 3 K-Shell Lines of Iron and a Coherent Pulsation of 593s from SAX J1748.2-2808
Koyama, Katsuji; Matsumoto, Hironori; Nobukawa, Masayoshi +1 more
SAX J1748.2-2808 is a unique X-ray object with a flat spectrum and strong emission lines at 6.4--7.0keV. The Suzaku satellite resolved the emission lines into 3 K-shell lines from neutral and highly ionized irons. A clear coherent pulsation with a period of 593s was found from the Suzaku and XMM-Newton archives. These facts favor that SAX J1748.2-…
Concerning the occurrence pattern of flux transfer events on the dayside magnetopause
Sibeck, D. G.
We present an analytical model for the magnetic field perturbations associated with flux transfer events (FTEs) on the dayside magnetopause as a function of the shear between the magnetosheath and magnetospheric magnetic fields and the ratio of their strengths. We assume that the events are produced by component reconnection along subsolar reconne…
Eta Carinae Across the 2003.5 Minimum: Analysis in the Visible and Near-Infrared Spectral Region
Weis, K.; Stahl, O.; Bomans, D. J. +3 more
We present an analysis of the visible through near-infrared spectrum of Eta Carinae (η Car) and its ejecta obtained during the "η Car Campaign with the Ultraviolet and Visual Echelle Spectrograph (UVES) at the ESO Very Large Telescope (VLT)." This is a part of larger effort to present a complete η Car spectrum, and extends the previously presented…
Formation Heights of Extreme Ultraviolet Lines in an Active Region Derived by Correlation of Doppler Velocity and Magnetic Field
Ding, M. D.; Guo, Y.; Wiegelmann, T. +1 more
We study the correlation heights, which indicate the formation height of Extreme Ultraviolet (EUV) lines in an active region using observations from the EUV Imaging Spectrometer and Solar Optical Telescope on board Hinode. The nonlinear force-free field optimization method is adopted to extrapolate the three-dimensional magnetic fields to higher l…
Multiple-spacecraft study of an extended magnetic structure in the solar wind
Inhester, B.; Zong, Q. -G.; Marsch, E. +6 more
An extended magnetic structure was observed consecutively by five spacecraft (ACE, WIND, STEREO A and B, and CLUSTER) in the solar wind on 15 January 2007. The similar bipolar magnetic field variations from five spacecraft suggest that the magnetic structure is two-dimensional. The abrupt disappearance of the beam electrons in the core of the stru…
Discovery, Photometry, and Kinematics of Planetary Nebulae in M 82
Johnson, L. C.; Méndez, R. H.; Teodorescu, A. M.
Using an [O III] λ5007 on-band/off-band filter technique, we identify 109 planetary nebulae (PNe) candidates in the edge-on spiral galaxy M 82, using the FOCAS instrument at the 8.2 m Subaru Telescope. The use of ancillary high-resolution Hubble Space Telescope Advanced Camera for Surveys Hα imaging aided in confirming these candidates, helping to…
Characteristic Development of Magnetic Shear in a Flare-producing Sunspot Obtained from Vector Magnetic Field Measurements by Hinode
Magara, T.
One of the promising models for the initiation of a solar flare requires observation-based information at the solar surface where the energy released during a flare is injected in the way limited by a real environment. Hinode provides a time series of vector-field maps of the photospheric magnetic field in NOAA10930 that shows strong flaring activ…
Broad-Band Spectrum of the Black Hole Candidate IGR J17497-2821 Studied with Suzaku
Dotani, Tadayasu; Yamaoka, Kazutaka; Kokubun, Motohide +9 more
The broad-band 1--300keV Suzaku spectrum of IGR J17497-2821, the X-ray transient discovered by INTEGRAL in 2006 September, is presented. Suzaku observed IGR J17497-2821 on September 25, eight days after its discovery, for a net exposure of about 53 ks. During the Suzaku observation, IGR J17497-2821 is very bright, 2 × 1037erg s-1
Cloud structure in Venus middle-to-lower atmosphere as inferred from VEX/VIRTIS 1.74 µm data
Drossart, P.; Piccioni, G.; Imamura, T. +5 more
We have analyzed 1.74 µm nightside emission of Venus recorded using Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) onboard European Space Agency's (ESA) Venus Express (Orbit 344, 30-31 March 2007). Attention was paid to how infrared radiance, intense at the center of the 1.74 µm “window”, dims at an off-center wavelength (1…
Suzaku Observations of the Extreme MeV Blazar SWIFT J0746.3+2548
Takahashi, Tadayuki; Kataoka, Jun; Madejski, Greg +8 more
We report the Suzaku observations of the high luminosity blazar SWIFT J0746.3+2548 (J0746) conducted in 2005 November. This object, which, with z = 2.979, is the highest redshift source observed in the Suzaku Guaranteed Time Observer period, is likely to show high gamma-ray flux peaking in the MeV range. As a result of the good photon statistics a…