Search Publications
The X-ray activity of the slowly rotating G giant δ CrB
Gondoin, P.
δ CrB is a single G giant whose distinctive characteristics include an X-ray luminosity exceptionally high for a slowly rotating star. δ CrB was observed in March 2003 by the {XMM{-}Newton} observatory. The X-ray spectra of δ CrB are described by a MEKAL plasma model with two components at 6.5 ×106 K and 107 K. Series of line…
The Chinese ground-based instrumentation in support of the combined Cluster/Double Star satellite measurements
Wu, J.; Liu, R. -Y.; Yang, H. -G. +10 more
Ground-based observations can be used to provide substantial support for Cluster/Double Star measurements and greatly enhance the mission's scientific return. There are six Chinese ground stations involved in coordinated cluster/Double Star and ground-based instrument observations. Among them, the Chinese Zhongshan Station in Antarctica and the Ye…
Spectral Evolution of a Luminous Compact X-Ray Source in NGC 253 with Chandra and XMM-Newton Observatories
Makishima, Kazuo; Takahashi, Tadayuki; Kubota, Aya +2 more
Spectral studies of a luminous X-ray source, NGC 253 X21, are presented based on archival Chandra and XMM-Newton data. The Chandra observation on 1999 December 16 detected the source at a bolometric luminosity of 0.3 × 1039 erg s-1 (assuming isotropic emission), while an XMM-Newton observation on 2000 June 3 revealed a short-…
Analysis of Cluster spacecraft potential during active control
Escoubet, C. P.; André, M.; Décréau, P. M. E. +4 more
The floating potential of a spacecraft is determined by an equilibrium between photo-electron emission from the sunlit spacecraft surfaces and the plasma electron current, while other currents play a secondary role. On the Cluster spacecraft, the presence of the experiment ASPOC to control the potential by an ion beam with currents up to several t…
Orbit, Dynamical Mass, and MK Type of Visual Binary WOR 2
Docobo, J. A.; Balega, Y. Y.; Tamazian, V. S. +2 more
On the basis of new speckle measurements with the 6 m telescope of the Special Astrophysical Observatory (Russia) and Hipparcos astrometry, an improved orbital solution with a period of P=24.1 yr for the visual binary WOR 2 is obtained. The dynamical mass of the system is 1.40+/-0.25 Msolar. Differential photometry (Δm=0.55 mag) allowed…
The peculiar galaxy Mkn 298 revisited with integral field spectroscopy
Ciroi, S.; Rafanelli, P.; Radovich, M. +3 more
Spectroscopic and imaging data of the peculiar galaxy Mkn 298 are presented. Narrow-band Hα and broad-band R images are used to study the star formation rate in the galaxy and its morphology, which is typical of a merging system. Long-slit and integral field spectra are used to assess the kinematics of gas and stars, and the nature of the ionizing…
Accretion in Strong Gravity: from Galactic to Supermassive Black Holes
Done, Chris; Gierliński, Marek
The galactic black hole binary systems give an observational template showing how the accretion flow changes as a function of increasing mass accretion rate, or L/LEdd. These data can be synthesised with theoretical models of the accretion flow to give a coherent picture of accretion in strong gravity, in which the major hard-soft spect…
An investigation of Titan's aerosols using microwave analog measurements and radiative transfer modeling
Kolokolova, L.; Gustafson, B. Å. S.; Thomas-Osip, J. E. +1 more
A combination of laboratory experiments, theoretical modeling, and spacecraft observations is employed to characterize the aerosols in the atmosphere of Titan. The scattering properties of model aerosols were measured using the Microwave Analog Light Scattering Facility at the University of Florida and complemented with theoretical modeling of sin…
Fine-time energetic electron behavior observed by Cluster/RAPID in the magnetotail associated with X-line formation and subsequent current disruption
Zong, Q. -G.; Daly, P. W.; Baker, D. N. +3 more
Energetic electrons with 90deg pitch angle have been observed in the magnetotail at ~19 RE near local midnight during the recovery phase of a substorm event on 27 August 2001 (Baker et al., 2002). Based on auroral images Baker et al. (2002) placed the substorm expansion phase between ~04:06:16 and ~04:08:19 UT. The electron enhancements…
Waiting Time Distribution of Coronal Mass Ejections
Ding, Ming-De; Chen, Peng-Fei; Yeh, Chin-Teh
Inspired by the finding that the large waiting time of solar flares presents a power-law distribution, we investigate the waiting time distribution (WTD) of coronal mass ejections (CMEs). SOHO/LASCO CME observations from 1996 to 2003 are used in this study. It is shown that the observed CMEs have a similar power-law behavior to the flares, with an…