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Particle Acceleration by Magnetic Reconnection in AGNs and in the IGM
Particle Acceleration Magnetic Reconnection AGNs IGM
2011/10/9
There is no single mechanism by which fast particles are accelerated in astrophysical environments, and it is now recognized that the data require a rich variety of different mechanisms operating unde...
The Microquasar Cyg X-1: A Short Review
accretion, accretion disks – black hole physics – X-rays:binaries
2011/10/8
We review the spectral properties of the black hole candidate Cygnus X-1. Specifically, we discuss two recent sets of multi-satellite observations. One comprises a 0.5-500 keV spectrum, obtained with ...
High-ion absorption in the proximate damped Lyman-alpha system toward Q0841+129
quasars: absorption lines – galaxies: high-redshift – galaxies: halos – galaxies: ISM
2011/10/8
We present VLT/UVES spectroscopy of the quasar Q0841+129, whose spectrum shows a proximate damped Lyman-alpha (PDLA) absorber at z=2.47621 and a proximate sub-DLA at z=2.50620, both lying close in red...
Continuous upflows and sporadic downflows observed in active regions
Sun : corona – Sun: transition region – Sun : UV radiation
2011/9/30
We present a study of the temporal evolution of coronal loops in active regions and its implications for the dynamics in coronal loops. We analyzed images of the Atmospheric Imaging Assembly (AIA) on ...
Spectroscopic evidence for helicity in explosive events
Sun: UV radiation—Sun: transition region— Sun: chromosphere
2011/9/30
We report spectroscopic observations in support of a novel view of transition region explosive events, observations that lend empirical evidence that at least in some cases explosive events may be not...
Center-to-Limb Variation of Radio Emissions from Thermal-Rich and Thermal-Poor Solar Flares
acceleration of particles—Sun: fl ares—Sun: magnetic fi elds—Sun:radio radiation—Sun: X-rays, gamma rays
2011/9/30
A statistical analysis of radio flare events was performed by using the event list of Nobeyama Radioheliograph in 1996-2009. We examined center-to-limb variations of 17GHz and 34GHz flux by dividing t...
Quasi periodic oscillations of solar active regions in connection with their flare activity - NoRH observations
Oscillations, Solar Radio Emission Radio Bursts, Association with Flares
2011/9/29
The sunspot-associated sources at the frequency of 17 GHz give information on plasma parameters in the regions of magnetic field about B=2000 G at the level of the chromosphere-corona transition regio...
We have conducted an LTE abundance analysis for SAO 40039 a warm post-AGB star whose spectrum is known to show surprisingly strong He I lines for its effective temperature and has been suspected of be...
We study the change in cosmic-ray pressure, the change in cosmic-ray density, and the level of cosmic-ray induced heating via Alfven-wave damping when cosmic rays move from a hot ionized plasma to a c...
Determination of a magnetization parameter of the parsec-scale AGN jets
Determination magnetization parameter parsec-scale AGN jets
2011/9/27
The observed shift of the core of the relativistic AGN jets as a function of frequency allows us to evaluate the number density of outflowing plasma and, hence, the magnetization parameter. New analys...
VHE gamma-ray Emission from Passive Supermassive Black Holes: Constraints for NGC 1399
Emission Passive Supermassive Black Holes
2011/9/28
Very high energy (VHE; >100 GeV) gamma-rays are expected to be emitted from the vicinity of super-massive black holes (SMBH), irrespective of their activity state. In the magnetosphere of rotating SMB...
Multiwavelength campaign on Mrk 509. V. Chandra-LETGS observation of the ionized absorber
Galaxies: individual: Mrk 509 – Galaxies: Seyfert – quasars: absorption lines – X-rays: galaxies
2011/9/27
We present here the results of a 180 ks Chandra-LETGS observation as part of a large multi-wavelength campaign on Mrk 509. We study the warm absorber in Mrk 509 and use the data from a simultaneous HS...
Multiwavelength campaign on Mrk 509. III. The 600 ks RGS spectrum: unravelling the inner region of an AGN
Active Galactic Nuclei – X-ray spectroscopy – XMM-Newton – outfl ows – individual: Mrk 509 – galaxies: Seyfert
2011/9/27
We present the results of our 600 ks RGS observation as part of the multiwavelength campaign on Mrk 509. The very high quality of the spectrum allows us to investigate the ionized outflow with an unpr...
Multi-Wavelength Observations of a Flux Rope Failed in the Eruption and Associated M-Class Flare from NOAA AR 11045
coronal loops magnetic eld ux rope magnetic reconnection
2011/9/27
We present the multi-wavelength observations of a flux rope that was trying to erupt from NOAA AR 11045 and the associated M-class solar flare on 12 February 2010 using space and ground based observat...
A Generalized Flux Function for Three-dimensional Magnetic Reconnection
Generalized Flux Function Three-dimensional Magnetic Reconnection
2011/10/18
The definition and measurement of magnetic reconnection in three-dimensional magnetic fields with multiple reconnection sites is a challenging problem, particularly in fields lacking null points. We p...