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Active Galactic Nuclei emit over the entire electromagnetic spectrum with the peak of the accretion disk emission in the far-UV, a wavelength range historically difficult to investigate. We use here the GALEX (Galaxy Evolution Explorer)…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Elena Marchese , R. Della Ceca , A. Caccianiga , A. Corral , P. Severgnini

Experiments searching for neutrinoless double beta decay ($0\nu\beta\beta$) require precise energy calibration and extremely low backgrounds. One of the most popular isotopes for $0\nu\beta\beta$ experiments is $^{136}$Xe. In support of…

Nuclear Experiment · Physics 2018-12-19 S. J. Daugherty , J. B. Albert , L. J. Kaufman , M. Devlin , N. Fotiades , R. O. Nelson , M. Krtička

We present here a new spectral energy distribution (SED) fitting approach that we adopt to select radio-excess sources amongst distant star-forming galaxies in the GOODS-Herschel (North) field and to reveal the presence of hidden, highly…

Variable speed of light (VSL) theories generically lead to large violations of charge conservation that can be written in terms of a dimensionless parameter $\lambda$. It is shown that the motion of the Earth with respect to the Sun could…

Astrophysics · Physics 2011-06-02 Manuel Torres , Hector Vucetich

The variability of active galactic nuclei (AGNs) is ubiquitous but has not yet been understood. Measuring the optical variation properties of AGNs, such as variation timescale and amplitude, and then correlating them with their fundamental…

Astrophysics of Galaxies · Physics 2024-01-11 Xu-Fan Hu , Zhen-Yi Cai , Jun-Xian Wang

We report on the discovery of one of the most extreme cases of high-frequency radio variability ever measured in active galactic nuclei (AGN), observed on timescales of days and exhibiting variability amplitudes of three to four orders of…

The spectroscopic analysis of 117 serendipitous sources in the HELLAS2XMM 1df (1 degree field) survey is described. Of these, 106 sources, of which 86% have a spectroscopic redshift, are used to evaluate the fraction of X-ray absorbed (log…

Some electroweak models with extended neutral currents, such as those based on the $E_6$ group, lead to an increase of the $\bar{\nu}-e$ scattering cross section at energies below 100 keV. We propose to search for the heavy Z' boson…

High Energy Physics - Phenomenology · Physics 2009-09-17 I. Barabanov , P. Belli , R. Bernabei , V. I. Gurentsov , V. N. Kornoukhov , O. G. Miranda , V. B. Semikoz , J. W. F. Valle

Over the last decade, experimental measurements of electrostatic screening lengths in concentrated electrolytes have exceeded theoretical predictions by orders of magnitude. This disagreement has led to a paradigm in which such screening…

The STEREO experiment is designed to test the hypothesis of light sterile neutrinos being the cause of the Reactor Antineutrino Anomaly. It measures the antineutrino energy spectrum from the compact core of the ILL research reactor in six…

High Energy Physics - Experiment · Physics 2019-09-04 Stefan Schoppmann

We present a systematic investigation of extremely X-ray variable active galactic nuclei (AGNs) in the $\approx 5.3~{\rm deg}^2$ XMM-SERVS XMM-LSS region. Eight variable AGNs are identified with rest-frame 2 keV flux density variability…

Astrophysics of Galaxies · Physics 2025-03-03 Zijian Zhang , Bin Luo , Linhua Jiang , W. N. Brandt , Jian Huang , Qingling Ni

The performance of the Advanced GAmma Tracking Array (AGATA) at GANIL is discussed, on the basis of the analysis of source and in-beam data taken with up to 30 segmented crystals. Data processing is described in detail. The performance of…

Differential cross sections of the reaction gamma d to K+ Sigma- (p) have been measured with the CLAS detector at Jefferson Lab using incident photons with energies between 1.1 and 3.6 GeV. This is the first complete set of strangeness…

Nuclear Experiment · Physics 2019-08-13 S. Anefalos Pereira , M. Mirazita , P. Rossi , E. De Sanctis , G. Niculescu , I. Niculescu , S. Stepanyan

We discuss the spectral analysis of a sample of 63 Active Galactic Nuclei (AGN) detected above a limiting flux of $S(8-24$ keV$)=7\times10^{-14}$ erg/s/cm$^2$ in the multi-tiered NuSTAR Extragalactic Survey program. The sources span a…

The ANTARES telescope is well suited to detect neutrinos produced in astrophysical transient sources as it can observe a full hemisphere of the sky at all times with a high duty cycle. The background and point source sensitivity can be…

High Energy Astrophysical Phenomena · Physics 2019-08-13 D. Dornic

Analysis of data from the EGRET gamma-ray detector on the Compton Gamma Ray Observatory indicated an anomaly in the form of an excess diffuse galactic flux at GeV energies over that which was theoretically predicted. Various explanations…

Astrophysics · Physics 2009-06-23 F. W. Stecker , S. D. Hunter , D. A. Kniffen

We explore oscillations of the solar $^8$B neutrinos in the Earth in detail. The relative excess of night $\nu_e$ events (the Night-Day asymmetry) is computed as function of the neutrino energy and the nadir angle $\eta$ of its trajectory.…

High Energy Physics - Phenomenology · Physics 2017-08-16 Ara Ioannisian , Alexei Yu. Smirnov , Daniel Wyler

Gamma ray burst (GRB) objects are now widely thought to be at cosmological distances, and thus represent enormous energy emission. Gamma ray spectra extending to $GeV$ energies suggest the possiblity of accompanying neutrino emission, and…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. J. Weiler , W. A. Simmons , S. Pakvasa , J. G. Learned

TANAMI is a multiwavelength program monitoring active galactic nuclei (AGN) south of -30deg declination including high-resolution Very Long Baseline Interferometry (VLBI) imaging, radio, optical/UV, X-ray and gamma-ray studies. We have…

We examine the reach of a Beta-beam experiment with two detectors at carefully chosen baselines for exploring neutrino mass parameters. Locating the source at CERN, the two detectors and baselines are: (a) a 50 kton iron calorimeter (ICAL)…

High Energy Physics - Phenomenology · Physics 2008-11-26 Sanjib Kumar Agarwalla , Sandhya Choubey , Amitava Raychaudhuri