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Constraints on dark matter models from a Fermi LAT search for high-energy cosmic-ray electrons from the Sun
Cosmic Rays Electrons Fermi Sun
2011/10/13
During its first year of data taking, the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope has collected a large sample of high-energy cosmic-ray electrons and positrons (CREs). ...
Gamma Ray Bursts in the comoving frame
Gamma-ray: bursts— Radiation mechanisms: non thermal
2011/10/12
We estimate the bulk Lorentz factor Gamma_0 of 32 GRBs using the measured peak time of their afterglow light curves. We consider two possible scenarios for the estimate of Gamma_0: the case of a homog...
Swift monitoring of the central X-ray source in RCW 103
pulsars: general – stars: neutron – X-rays: individual: 1E 161348–5055
2011/10/11
The X-ray source 1E 161348-5055 lies at the centre of the 2-kyr-old supernova remnant RCW 103. Owing to its 24-ks modulation, orders-of-magnitude flux variability over a few months/years, and lack of ...
Height structure of X-ray, EUV and white-light emission in a solar flare
Sun: fl ares – Sun: X-rays, gamma-rays – Sun: radio radiation – Sun: UV radiation – Acceleration of particles
2011/10/11
The bulk of solar flare emission originates from very compact sources located in the lower solar atmosphere and seen in various wavelength ranges: near optical, UV, EUV, soft and hard X-rays, and gamm...
Multimessenger astronomy with pulsar timing and X-ray observations of massive black hole binaries
Black hole physics – Accretion, accretion discs – Gravitational waves –pulsars: general – X-rays: general
2011/10/9
We demonstrate that very massive (>10^8\msun), cosmologically nearby (z<1) black hole binaries (MBHBs), which are primary targets for ongoing and upcoming pulsar timing arrays (PTAs), are particularly...
X-ray properties expected from AGN feedback in elliptical galaxies
X-ray properties expected feedback elliptical galaxies
2011/10/11
The ISM evolution of elliptical galaxies experiencing feedback from accretion onto a central black hole was studied recently with high-resolution 1D hydrodynamical simulations including radiative heat...
RXTE Observations of the Low-Mass X-Ray Binary 4U 1608-522 in Upper-Banana State
RXTE Observations Low-Mass X-Ray Binary 4U 1608-522 Upper-Banana State
2011/10/11
To investigate the physics of mass accretion onto weakly-magnetized neutron stars, 95 archival RXTE datasets of an atoll source 4U 1608-522, acquired over 1996-2004 in so-called upper-banana state, we...
The Be/X-ray binary A0535+26 during its recent 2009/2010 outbursts
Be/X-ray binary A0535+26 during recent 2009/2010 outbursts
2011/10/10
The Be/X-ray binary A0535+26 showed a giant outburst in December 2009 that reached ~5.14 Crab in the 15-50 keV range. Unfortunately, due to Sun constraints it could not be observed by most X-ray satel...
Measurement of Cosmic Ray antiproton/proton flux ratio at TeV energies with ARGO-YBJ
Extensive Air Showers Cosmic Rays Moon shadow antiproton ARGO-YBJ
2011/10/10
Cosmic ray antiprotons provide an important probe for the study of cosmic-ray propagation in the interstellar space and to investigate the existence of Galactic dark matter. The ARGO-YBJ experiment, l...
Observation of the Cosmic Ray Moon shadowing effect with the ARGO-YBJ experiment
Extensive Air Showers, Cosmic Rays, Moon shadow, Geomagnetic fi eld, ARGO-YBJ
2011/10/10
Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called \emph{Moon shadow}). The Moon shadow is an important tool to determine the performance of an air shower a...
Broad Line Radio Galaxies Observed with Fermi-LAT: The Origin of the GeV Gamma-Ray Emission
Broad Line Radio Galaxies Fermi-LAT:OriginGeV Gamma-Ray Emission
2011/10/10
We report on a detailed investigation of the gamma-ray emission from 18 broad line radio galaxies (BLRGs) based on two years of Fermi Large Area Telescope (LAT) data. We confirm the previously reporte...
Quasi-Periodic Pulsations in Solar Flares: new clues from the Fermi Gamma-Ray Burst Monitor
Sun: fl ares Methods:data analysis Methods: statistical Methods:observational
2011/10/8
In the last four decades it has been observed that solar flares show quasi-periodic pulsations (QPPs) from the lowest, i.e. radio, to the highest, i.e. gamma-ray, part of the electromagnetic spectrum....
Gas Gain Measurements from a Negative Ion TPC X-ray Polarimeter
Gas Gain Measurements Negative TPC X-ray Polarimeter
2011/10/9
Gas-based time projection chambers (TPCs) have been shown to be highly sensitive X-ray polarimeters having excellent quantum efficiency while at the same time achieving large modulation factors. To ob...
The relation of optical/UV and X-ray emission in low-luminosity active galactic nuclei
relation optical/UV X-ray emission low-luminosity active galactic nuclei
2011/10/9
We study the relation of optical/UV and X-ray emission in the low luminosity active galactic nuclei (LLAGNs), using a sample of 49 sources including 28 local Seyfert galaxies and 21 low-ionization nuc...
On the Extended Emission of the Anomalous X-ray Pulsar 1E 1547.0-5408
Extended Emission Anomalous X-ray Pulsar
2011/10/9
We present an analysis of the extended emission around the anomalous X-ray pulsar 1E 1547.0-5408 using four XMM-Newton observations taken with the source in varying states of outburst as well as in qu...