Search Publications
Study of Three ICMEs Events Registered by Ulysses in 2001
Dumitrache, Cristiana; Popescu, Nedelia A.
In-situ data measured by Ulysses-SWOOPS, SWICS and VHM instruments-are used for the study of magnetic field and solar wind plasma parameters for the year 2001, in an attempt of founding new ICMEs based on the combination of classical identification conditions, plasma dynamics signatures, and plasma composition signatures. Three new candidates are …
An empirical method to correct the saturation seen in the SOHO/MDI magnetograms
Liu, Yang; Zhao, Yong-Heng; Zhendong Gao, George
The magnetic field of the umbrae is sometimes found to be saturated in the magnetograms taken by the Michelson Doppler Imager (MDI) onboard the Solar and Heliospheric Observatory (SOHO). It is suggested that the combination of the low intensity of sunspot umbrae and the limitation of the 15-bit onboard numerical data acquisition leads to this satu…
Spectral Energy Distribution of Hyper-Luminous Infrared Galaxies
Miniutti, G.; Carrera, F. J.; Panessa, F. +1 more
The relationship between star formation and super-massive black hole growth is central to our understanding of galaxy formation and evolution. Hyper-Luminous Infrared Galaxies (HLIRGs) are unique laboratories to investigate the starburst-AGN connection, since they exhibit extreme star formation rates, and most of them show evidence of harboring po…
X-ray spectral study of hot gas in three clusters of galaxies
Kaastra, J. S.; de Plaa, J.; Costantini, E. +4 more
Aims: We studied the physical properties of three clusters of galaxies, selected from a BeppoSAX wide field camera (WFC) survey. These sources are identified as
Pulse Characterization of GRBs with Known Redshift
Kawai, Nobuyuki; Vasquez, Nicolas
Gamma-ray Bursts (GRBs) are one of the most promising tools in the study of cosmology. The luminosity, energy, light curve parameters and spectral measures could yield to the calibration of standard candles in the Universe. Nevertheless, cosmological and non-cosmological effects are not well understood. Aiming to clarify the possible effects, we s…
Fe Kα Line in the Integrated Spectrum of Serendipitous 2XMM Catalog Sources
Brusa, M.; Chaudhary, P.
We exploited the 2XMM catalog and archival products to investigate the properties of the Fe Kα line at different redshifts. Individual source spectra are stacked in different redshift and luminosity bins over the range 0<z<=5. We report that the narrow Fe Kα line is significantly detected up to z = 2. We find compelling evidence for the `X-r…
Spectral evolution of the Atoll source 4U 1728-34 with RXTE and INTEGRAL: evidence for hard X-ray tail
Belloni, T.; Homan, J.; Ubertini, P. +3 more
We report the temporal and spectral results on the INTEGRAL and RXTE 2006-2007 observation campaign of the Atoll source 4U 1728-34 (GX 354-0). The source shows, more than once, spectral evolution as revealed by the hardness intensity diagram. The soft state is well described by a Comptonization with an electron temperature of 3 keV and a high opti…
Hard X-ray properties of magnetic cataclysmic variables
Hill, A. B.; Knigge, C.; Bird, A. J. +9 more
We have constructed a new sample of magnetic cataclysmic variables (mCVs) by cross-correlating candidate sources detected in INTEGRAL/IBIS observations against catalogues of known CVs and included mCVs observed with either Swift/BAT or SUZAKU/HXD. Here we review the properties arising from this hard X-ray selected sample and find that most hard X-…
Coronal Fine Linear Rays: Are They Fast Streams From Active Regions?
Golub, Leon; Filippov, Boris; Lamy, Philippe +3 more
Eclipse observations of the W-L corona show linear rays above active regions at times of solar maximum. We show that these linear rays are also observed in the field-of-view of the C2-LASCO coronagraph, in perfect correspondence with the eclipse results. A selected prominent case taken from the 2001 eclipse observation in Angola is analysed with s…
Effect of Shock Normal Orientation Fluctuations on Field-Aligned Beam Distributions
Lucek, E. A.; Mazelle, C.; Wilber, M. +5 more
We address the unsolved question of how foreshock field-aligned beam (FAB) parallel temperatures are produced. Studies including numerical simulations and recent observations have indicated that shocks can be nonstationary and include embedded spatial structures with varied scales. As a first step towards assessing the impact of such variability o…