23,891 research outputs found
Clear detection of dusty torus signatures in a Weak-Line Radio Galaxy: the case of PKS 0043-42
We report the clearest detection to date of dusty torus signatures in a
Weak-Line Radio Galaxy (WLRG). The deep Spitzer InfraRed Spectrograph (IRS)
rest-frame mid-infrared (MIR) spectrum of the WLRG PKS 0043-42 (z=0.116) shows
a clear spectral turnover at wavelengths longer than ~20 micron suggestive of
warm dust, as well as a 9.7 micron silicate absorption feature. In addition,
the hard X-ray results, based on Chandra data, strongly support a picture in
which PKS 0043-42 has a torus and accretion disc more typical of Strong-Line
Radio Galaxies (SLRGs). The MIR and X-ray spectra are markedly different from
those of other WLRGs at similar redshifts, and here we show that the former can
be successfully fitted with clumpy torus models with parameters characteristic
of Type-2 AGN tori: close to edge-on (i=74 deg) and relatively broad (torus
angular width=60 deg), with an outer radius of 2 pc, hydrogen column density
~1.6x10^(23) cm^(-2), and AGN bolometric luminosity ~1.6x10^(44) erg s^(-1).
The presence of a compact torus in PKS 0043-42 provides evidence that this WLRG
is fuelled by cold, rather than hot, gas accretion. We suggest that WLRGs are a
diverse population, and PKS 0043-42 may represent a type of radio galaxy in
which the AGN activity has been recently re-triggered as a consequence of
intermittent gas supply, or in which the covering factor of the Narrow-Line
Region (NLR) clouds is relatively low.Comment: 7 pages, 6 figures, 1 table. Accepted by MNRA
Experimental status of deeply bound kaonic states in nuclei
We review recent claims of the existence of deeply bound kaonic states in
nuclei. Also we study in details the (K-,p) reaction on C12 with 1 GeV/c
momentum kaon beam, based on which a deep kaon nucleus optical potential was
claimed in [1]. In our Monte Carlo simulation of this reaction we include not
only the quasi-elastic K- p scattering, as in [1], but also K- absorption by
one and two nucleons followed by the decay of the hyperon in pi N, which can
also produce strength in the region of interest. The final state interactions
in terms of multiple scattering of the K-, p and all other primary particles on
their way out of the nucleus is also considered. We will show that all these
additional mechanisms allow us to explain the observed spectrum with a
"standard" shallow kaon nucleus optical potential obtained in chiral models.
[1] T. Kishimoto et al., Prog. Theor. Phys. 118, 181 (2007).Comment: 5 pages, 3 figures. To be published in the Proceedings of the
International Workshop on Chiral Symmetry in Hadrons and Nuclei (Chiral10),
Valencia, Spain, June 21-24, 201
The Effects of Tart Cherry Supplement on Markers of Inflammation and Quality of Life in Arthritic Patients
Please refer to the pdf version of the abstract located adjacent to the title
Latest results for the antikaon-nucleon optical potential
The key question of this letter is whether the K-nucleus optical potential is
deep, as it is prefered by the phenomenological fits to kaonic atoms data, or
shallow, as it comes out from unitary chiral model calculations. The current
experimental situation is reviewed.Comment: 3 pages, 1 figure. Presented at the 21st European Conference on the
Few-Body problems in Physics (EFB21), Salamanca, Spain, August 29 - September
3, 201
Comparison of coherence times in three dc SQUID phase qubits
We report measurements of spectroscopic linewidth and Rabi oscillations in
three thin-film dc SQUID phase qubits. One device had a single-turn Al loop,
the second had a 6-turn Nb loop, and the third was a first order gradiometer
formed from 6-turn wound and counter-wound Nb coils to provide isolation from
spatially uniform flux noise. In the 6 - 7.2 GHz range, the spectroscopic
coherence times for the gradiometer varied from 4 ns to 8 ns, about the same as
for the other devices (4 to 10 ns). The time constant for decay of Rabi
oscillations was significantly longer in the single-turn Al device (20 to 30
ns) than either of the Nb devices (10 to 15 ns). These results imply that
spatially uniform flux noise is not the main source of decoherence or
inhomogenous broadening in these devices.Comment: 4 pages, 5 figures, accepted for publication in IEEE Trans. Appl.
Supercon
Final State Interactions in Hypernuclear Decay
We present an update of the One-Meson-Exchange (OME) results for the weak
decay of s- and p-shell hypernuclei (Ref. Phys. Rev. C {\bf 56}, 339 (1997)),
paying special attention to the role played by final state interactions between
the emitted nucleons. The present study also corrects for a mistake in the
inclusion of the and exchange mechanisms, which substantially
increases the ratio of neutron-induced to proton-induced transitions,
. With the most up-to-date model ingredients, we find that
the OME approach is able to describe very satisfactorily most of the measured
observables, including the ratio .Comment: 20 pages, 2 eps figure
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