3,065 research outputs found
A possible optical counterpart to the old nearby pulsar J0108-1431
The multi-wavelength study of old (>100 Myr) radio pulsars holds the key to
understanding the long-term evolution of neutron stars, including the advanced
stages of neutron star cooling and the evolution of the magnetosphere.
Optical/UV observations are particularly useful for such studies because they
allow one to explore both thermal and non-thermal emission processes. In
particular, studying the optical/UV emission constrains temperature of the bulk
of the neutron star surface, too cold to be measured in X-ray observations.Aim
of this work is to identify the optical counterpart of the very old (166 Myr)
radio pulsar J0108-1431. We have re-analyzed our original VLT observations
(Mignani et al. 2003), where a very faint object was tentatively detected close
to the radio position, near the edge of a field galaxy. We found that the
backward extrapolation of the PSR J0108-1431 proper motion recently measured by
CHANDRA(Pavlov et al. 2008) nicely fits the position of this object. Based on
that, we propose it as a viable candidate for the optical counterpart to PSR
J0108-1431. The object fluxes (U =26.4+/-0.3; B =27.9; V >27.8) are consistent
with a thermal spectrum with a brightness temperature of 9X10^4 K (for R = 13
km at a distance of 130 pc), emitted from the bulk of the neutron star surface.
New optical observations are required to confirm the optical identification of
PSR J0108-1431 and measure its spectrum.Comment: 5 pages, 4 figures, submitted to A&
Possible Experimental Evidence for Violation of Standard Electrodynamics, de Broglie Pilot Wave and Spacetime Deformation
We report and discuss the results of double-slit-like experiments in the
infrared range, which evidence an anomalous behaviour of photon systems under
particular (energy and space) constraints. These outcomes apparently disagree
both with standard quantum mechanics (Copenhagen interpretation) and with
classical and quantum electrodynamics. Possible interpretations can be given in
terms of either the existence of de Broglie-Bohm pilot waves associated to
photons, and/or the breakdown of local Lorentz invariance (LLI). We put forward
an intriguing hypothesis about the possible connection between these seemingly
unrelated points of view by assuming that the pilot wave of a photon is, in the
framework of LLI breakdown, a local deformation of the flat minkowskian
spacetime.Comment: 15 pages, 6 figures, presented at CASYS'09 - International Conference
on COMPUTING ANTICIPATORY SYSTEMS - HEC Management School - University of
Liege, LIEGE, Belgium, August 3-8, 2009. The paper was peer reviewed as
explicitely stated on page x in the AIP CONFERENCE PROCEEDINGS 1303 -
Computing Anticipatory Systems - CASYS'09 Ninth International Conference,
Li\`ege Belgium, August 3-8, 200
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