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S. Reynolds

Publications and source records attributed to S. Reynolds.

3 recordsLinked to original sources

NuSTAR observations of G11.2-0.3

We present in this paper the hard X-ray view of the pulsar wind nebula in G11.2-0.3 and its central pulsar PSR J1811-1925 as seen by NuSTAR. We complement the data with Chandra for a more complete picture and confirm the existence of a hard, power-law component in the shell with photon index Gamma = 2.1 +/- 0.1, which we attribute to synchrotron emission. Our imaging observations of the shell show a slightly smaller radius at higher energies, consistent with Chandra results, and we find shrinkage as a function of increased energy along the jet direction, indicating that the electron outflow in the PWN may be simpler than that seen in other young PWNe. Combining NuSTAR with Integral, we find that the pulsar spectrum can be fit by a power-law with Gamma=1.32 +/- 0.07 up to 300 keV without evidence of curvature.

astro-ph.HE

Chandra Smells a RRAT: X-ray Detection of a Rotating Radio Transient

"Rotating RAdio Transients" (RRATs) are a newly discovered astronomical phenomenon, characterised by occasional brief radio bursts, with average intervals between bursts ranging from minutes to hours. The burst spacings allow identification of periodicities, which fall in the range 0.4 to 7 seconds. The RRATs thus seem to be rotating neutron stars, albeit with properties very different from the rest of the population. We here present the serendipitous detection with the Chandra X-ray Observatory of a bright point-like X-ray source coincident with one of the RRATs. We discuss the temporal and spectral properties of this X-ray emission, consider counterparts in other wavebands, and interpret these results in the context of possible explanations for the RRAT population.

astro-ph

Morphology of the galaxy distribution from wavelet denoising

We have developed a method based on wavelets to obtain the true underlying smooth density from a point distribution. The goal has been to reconstruct the density field in an optimal way ensuring that the morphology of the reconstructed field reflects the true underlying morphology of the point field which, as the galaxy distribution, has a genuinely multiscale structure, with near-singular behavior on sheets, filaments and hotspots. If the discrete distributions are smoothed using Gaussian filters, the morphological properties tend to be closer to those expected for a Gaussian field. The use of wavelet denoising provide us with a unique and more accurate morphological description.

astro-ph