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Why Have Many of the Brightest Radio-loud Blazars Not Been Detected in Gamma-Rays by Fermi?

2015

We use the complete MOJAVE 1.5 Jy sample of active galactic nuclei (AGNs) to examine the gamma-ray detection statistics of the brightest radio-loud blazars in the northern sky. We find that 23% of these AGNs were not detected above 0.1 GeV by the Fermi-LAT during the four-year 3FGL catalog period partly because of an instrumental selection effect and partly due to their lower Doppler boosting factors. Blazars with synchrotron peaks in their spectral energy distributions located below 10^(13.4) Hz also tend to have high-energy peaks that lie below the 0.1 GeV threshold of the LAT, and are thus less likely to be detected by Fermi. The non-detected AGNs in the 1.5 Jy sample also have significa…

AstrofísicaActive galactic nucleusmedia_common.quotation_subjectAstrophysics::High Energy Astrophysical Phenomenajets [galaxies]AstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysicsgeneral [gamma-ray burst]7. Clean energy01 natural scienceslaw.inventionsymbols.namesakelaw0103 physical sciencesBlazar010303 astronomy & astrophysicsAstrophysics::Galaxy Astrophysicsmedia_commonPhysicsgeneral [quasars]010308 nuclear & particles physicsScatteringSpectral densityAstronomy and Astrophysicsgalaxies [radio continuum]Synchrotron13. Climate actionSpace and Planetary ScienceSkyactive [galaxies]AstronomiasymbolsDoppler effectFermi Gamma-ray Space Telescope

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Halo-independent methods for inelastic dark matter scattering

2013

We present halo-independent methods to analyze the results of dark matter direct detection experiments assuming inelastic scattering. We focus on the annual modulation signal reported by DAMA/LIBRA and present three different halo-independent tests. First, we compare it to the upper limit on the unmodulated rate from XENON100 using (a) the trivial requirement that the amplitude of the annual modulation has to be smaller than the bound on the unmodulated rate, and (b) a bound on the annual modulation amplitude based on an expansion in the Earth's velocity. The third test uses the special predictions of the signal shape for inelastic scattering and allows for an internal consistency check of …

AstrofísicaParticle physicsCosmology and Nongalactic Astrophysics (astro-ph.CO)Dark matterFOS: Physical sciencesInelastic scattering01 natural sciencesSignalPartícules (Física nuclear)High Energy Physics - Phenomenology (hep-ph)0103 physical sciences010306 general physicsPhysicsdark matter theory010308 nuclear & particles physicsScatteringdark matter experimentsAstrophysics::Instrumentation and Methods for AstrophysicsAstronomy and AstrophysicsComputational physicsDark matter haloHigh Energy Physics - PhenomenologyAmplitudeModulationHaloAstronomia Aparells i instrumentsAstrophysics - Cosmology and Nongalactic Astrophysics

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VLBA observations of a rare multiple quasar imaging event caused by refraction in the interstellar medium

2013

We report on the first detection of the theoretically-predicted rare phenomenon of multiple parsec-scale imaging of an active galactic nucleus induced by refractive effects due to localized foreground electron density enhancements, e.g., in an AU-scale plasma lens(es) in the ionized component of the Galactic interstellar medium. We detected multiple imaging in the low galactic latitude (b=-2 deg) quasar 2023+335 from the 15.4 GHz MOJAVE observations when the source was undergoing an ESE. While the parsec-scale jet of the source normally extends along PA -20 deg, in the 28 May 2009 and 23 July 2009 images a highly significant multi-component pattern of secondary images is stretched out nearl…

AstrofísicaProper motionActive galactic nucleusCosmology and Nongalactic Astrophysics (astro-ph.CO)Astrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesAstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencesAngular diameter0103 physical sciencesVery-long-baseline interferometry010303 astronomy & astrophysicsAstrophysics::Galaxy AstrophysicsLine (formation)PhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)010308 nuclear & particles physicsScatteringAstronomy and AstrophysicsQuasarInterstellar mediumSpace and Planetary ScienceAstronomiaAstrophysics - High Energy Astrophysical PhenomenaAstrophysics - Cosmology and Nongalactic Astrophysics

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Cosmological analogies in the search for new physics in high-energy collisions

2020

In this paper, analogies between multiparticle production in high-energy collisions and the time evolution of the early universe are discussed. A common explanation is put forward under the assumption of an unconventional early state: a rapidly expanding universe before recombination (last scattering surface), followed by the CMB, later evolving up to present days, versus the formation of hidden/dark states in hadronic collisions followed by a conventional QCD parton shower yielding final-state particles. In particular, long-range angular correlations are considered pointing out deep connections between the two physical cases potentially useful for the discovery of new physics.

Astrophysics and AstronomyParticle physicsCosmology and Nongalactic Astrophysics (astro-ph.CO)Physics beyond the Standard Modelmedia_common.quotation_subjectCosmic microwave backgroundFOS: Physical sciences01 natural sciencesMetric expansion of spaceHigh Energy Physics - Phenomenology (hep-ph)0103 physical sciencesNuclear Experiment010306 general physicsParton showerParticle Physics - Phenomenologymedia_commonPhysicsQuantum chromodynamics010308 nuclear & particles physicsScatteringTime evolutionhep-phUniverseHigh Energy Physics - Phenomenologyastro-ph.COAstrophysics - Cosmology and Nongalactic Astrophysics

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