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The energy spectrum of cosmic-ray electrons at TeV energies
H. E. S. S. Collaboration, :, F. Aharonian
The very large collection area of ground-based gamma-ray telescopes gives them a substantial advantage over balloon/satellite based instruments in the detection of very-high-energy…
Limits on an Energy Dependence of the Speed of Light from a Flare of the Active Galaxy PKS 2155-304
H. E. S. S. Collaboration, :, F. Aharonian
In the past few decades, several models have predicted an energy-dependence of the speed of light in the context of quantum gravity. For cosmological sources such as active galaxie…
RE J1034+396: The origin of the soft X-ray excess and QPO
Matthew Middleton, Chris Done, Martin Ward +2
The X-ray quasi-periodic oscillation (QPO) seen in RE J1034+396 is so far unique amongst AGN. Here we look at the another unique feature of RE J1034+396, namely its huge soft X-ray…
A ~1-hour X-ray periodicity in an active galaxy RE J1034+396
Marek Gierlinski, Matthew Middleton, Martin Ward +1
Active galactic nuclei and quasars are thought to be scaled up versions of Galactic black hole binaries, powered by accretion onto supermassive black holes with masses of 10^6-10^9…
New insights into the X-ray properties of the nearby barred spiral galaxy NGC 1672
L. P. Jenkins, W. N. Brandt, E. J. M. Colbert +4
We present some preliminary results from new Chandra and XMM-Newton X-ray observations of the nearby barred spiral galaxy NGC1672. It shows dramatic nuclear and extra-nuclear star…
Optical emission line properties of Narrow Line Seyfert 1s and comparison AGN
James R. Mullaney, Martin J. Ward
Based on a new spectroscopic sample observed using the WHT, we examine the kinematic properties of the various emission line regions in narrow line Seyfert 1 galaxies (NLS1s) by mo…