Search Publications
Ion Temperature and Non-Thermal Velocity in a Solar Active Region: Using Emission Lines of Different Atomic Species
Hara, H.; Watanabe, T.; Imada, S.
We have studied the characteristics of the ion thermal temperature and non-thermal velocity in an active region observed by the EUV Imaging Spectrometer onboard Hinode. We used two emission lines of different atomic species (Fe XVI 262.98 Å and S XIII 256.69 Å) to distinguish the ion thermal velocity from the observed full width at half-maximum. W…
High-precision multi-band measurements of the angular clustering of X-ray sources
Ebrero, J.; Carrera, F. J.; Watson, M. G. +2 more
Aims: We aim to study the large-scale structure of an extragalactic serendipitous X-ray survey with unprecedented accuracy thanks to the large statistics involved, and provide insight into the environment of AGN at the epochs when their space density declines (z ∼ 1{-}2).
Methods: In this paper we present the two-point angular correlation func…
Contrast of Coronal Holes and Parameters of Associated Solar Wind Streams
Obridko, V. N.; Shelting, B. D.; Livshits, I. M. +1 more
It is shown that the contrast of coronal holes, just as their size, determines the velocity of the solar wind streams. Fully calibrated EIT images of the Sun have been used. About 450 measurements in 284 Å have been analyzed. The time interval under examination covers about 1500 days in the declining phase of cycle 23. All coronal holes recorded f…
The Accuracy of Using the Ulysses Result of the Spatial Invariance of the Radial Heliospheric Field to Compute the Open Solar Flux
Lockwood, M.; Owens, M.
We survey observations of the radial magnetic field in the heliosphere as a function of position, sunspot number, and sunspot cycle phase. We show that most of the differences between pairs of simultaneous observations, normalized using the square of the heliocentric distance and averaged over solar rotations, are consistent with the kinematic "fl…
Phase-resolved XMM-Newton observations of the massive WR+O binary WR 22
Gosset, E.; Nazé, Y.; Rauw, G. +2 more
Aims. To better understand the phenomenon of colliding winds in massive binary stars, we study the X-ray lightcurve of a WR+O system of the Carina region, a system well known for the high mass of its primary.
Methods: Phase-resolved X-ray observations of the massive WR+O binary system WR 22 were performed with the XMM-Newton facility. We obser…
Suzaku Observation of the Radio Halo Cluster Abell 2319: Gas Dynamics and Hard X-Ray Properties
Nakazawa, Kazuhiro; Takizawa, Motokazu; Sugawara, Chika
We present the results of a Suzaku observation of the radio halo cluster Abell 2319 (A 2319). The metal abundance in the central cool region is found to be higher than the surrounding region, which was not resolved in former studies. We confirm that the line-of-sight velocities of the intracluster medium in the observed region are consistent with …
Detection of Hard X-Rays from the Compton-Thick Seyfert 2 Galaxy NGC 2273 with Suzaku
Fukazawa, Yasushi; Awaki, Hisamitsu; Terashima, Yuichi +1 more
We have obtained a broad-band spectrum of the Compton-thick Seyfert 2 galaxy NGC 2273 with Suzaku. The spectrum reveals the first detection of hard X-rays above ∼10keV from NGC 2273. The broad-band spectrum is well represented by a three component model, accompanied by both a strong iron Kα line with an equivalent width of ∼1.8keV and several weak…
Probing variability patterns of the Fe K line complex in bright nearby AGNs
Cappi, M.; Ponti, G.; Iwasawa, K. +5 more
Context: The unprecedented sensitivity of current X-ray telescopes allows the issue of the Fe K line complex variability patterns in bright, nearby AGNs to be addressed for the first time. These kinds of studies have the potential to map the accretion flow in the strong gravity regime of supermassive black holes.
Aims: We examine XMM-Newton ob…
Dipole tilt effects in plasma sheet By: statistical model and extreme values
Petrukovich, A. A.
With 11 years of Geotail measurements we construct a model of plasma sheet By, depending on IMF By, coordinates X,Y and geodipole tilt angle. At midnight and pre-midnight local times By is positively correlated with tilt (positive in summer). Thus in summer By is shifted towards positive values and in wi…
Study of white-light flares observed by Hinode
Wang, Hai-Min
White-light flares are considered to be the most energetic flaring events that are observable in the optical broad-band continuum of the solar spectrum. They have not been commonly observed. Observations of white-light flares with sub-arcsecond resolution have been very rare. The continuous high resolution observations of Hinode provide a unique o…