9,072 research outputs found
The first INTEGRAL-OMC catalogue of optically variable sources
The Optical Monitoring Camera (OMC) onboard INTEGRAL provides photometry in
the Johnson V-band. With an aperture of 50 mm and a field of view of 5deg x
5deg, OMC is able to detect optical sources brighter than V~18, from a
previously selected list of potential targets of interest. After more than nine
years of observations, the OMC database contains light curves for more than
70000 sources (with more than 50 photometric points each). The objectives of
this work have been to characterize the potential variability of the objects
monitored by OMC, to identify periodic sources and to compute their periods,
taking advantage of the stability and long monitoring time of the OMC. To
detect potential variability, we have performed a chi-squared test, finding
5263 variable sources out of an initial sample of 6071 objects with good
photometric quality and more than 300 data points each. We have studied the
periodicity of these sources using a method based on the phase dispersion
minimization technique, optimized to handle light curves with very different
shapes.In this first catalogue of variable sources observed by OMC, we provide
for each object the median of the visual magnitude, the magnitude at maximum
and minimum brightness in the light curve during the window of observations,
the period, when found, as well as the complete intrinsic and period-folded
light curves, together with some additional ancillary data.Comment: Accepted by Astronomy & Astrophysics; 13 pages, 16 figures. Figures'
resolution has been degraded to fit astro-ph constraint
The NMSSM lives: with the 750 GeV diphoton excess
We propose an NMSSM scenario that can explain the excess in the diphoton
spectrum at 750 GeV recently observed by ATLAS and CMS. We show that in a
certain limit with a very light pseudoscalar one can reproduce the experimental
results without invoking exotic matter. The 750 GeV excess is produced by two
resonant heavy Higgs bosons with masses ~750 GeV, that subsequently decay to
two light pseudoscalars. Each of these decays to collimated photon pairs that
appear as a single photon in the electromagnetic calorimeter. A mass gap
between heavy Higgses mimics a large width of the 750 GeV peak. The production
mechanism, containing a strong component via initial b quarks, ameliorates a
possible tension with 8 TeV data compared to other production modes. We also
discuss other constraints, in particular from low energy experiments. Finally,
we discuss possible methods that could distinguish our proposal from other
physics models describing the diphoton excess in the Run-II of the LHC.Comment: 24 pages, 4 figures; minor text improvements; to appear in EPJ
El teléfono como recurso en la enseñanza a distancia
Después de recordar brevemente el ayer y el hoy del Medio Telefónico nos preguntamos si puede considerarse como Medio Didáctico, analizando las características de un canal comunicativo. En la segunda parte se citan y se comentan algunas posibilidades que el Teléfono ofrece al docente como ayuda para la Organización y Gestión y como Medio para la acción docente
SUSY Dark Matter In Light Of CDMS/XENON Limits
In this talk we briefly review the current CDMS/XENON constraints on the
neutralino dark matter in three popular supersymmetric models: the minimal
(MSSM), the next-to-minimal (NMSSM) and the nearly minimal (nMSSM). The
constraints from the dark matter relic density and various collider experiments
are also taken into account. The conclusion is that for each model the current
CDMS/XENON limits can readily exclude a large part of the parameter space
allowed by other constraints and the future SuperCDMS or XENON100 can cover
most of the allowed parameter space. The implication for the Higgs search at
the LHC is also discussed. It is found that in the currently allowed parameter
space the MSSM charged Higgs boson is quite unlikely to be discovered at the
LHC while the neutral Higgs bosons and may be accessible at the LHC in
the parameter space with a large parameter.Comment: talk given at 2nd International Workshop on Dark Matter, Dark Energy
and Matter-Antimatter Asymmetry, Nov 5-6, 2010, Hsinchu, Taiwan (to appear in
Int. J. Mod. Phys. D
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