English
Related papers

Related papers: Mining the Blazar Sky

200 papers

Machine learning based approaches are emerging as very powerful tools for many applications including source classification in astrophysics research due to the availability of huge high quality data from different surveys in observational…

High Energy Astrophysical Phenomena · Physics 2023-07-05 A. Tolamatti , K. K. Singh , K. K. Yadav

Since mid-2007 we have carried out a dedicated long-term monitoring programme at 15 GHz using the Owens Valley Radio Observatory 40 meter telescope. One of the main goals of this programme is to study the relation between the radio and…

High Energy Astrophysical Phenomena · Physics 2015-06-23 W. Max-Moerbeck , J. L. Richards , T. Hovatta , V. Pavlidou , T. J. Pearson , A. C. S. Readhead , O. G. King , R. Reeves

Machine learning has emerged as a powerful tool in the field of gamma-ray astrophysics. The algorithms can distinguish between different source types, such as blazars and pulsars, and help uncover new insights into the high-energy universe.…

High Energy Astrophysical Phenomena · Physics 2024-01-05 Gopal Bhatta , Sarvesh Gharat , Abhimanyu Borthakur , Aman Kumar

We present a new type of search strategy designed specifically to find continuously emitting gravitational wave sources in known binary systems based on the incoherent sum of frequency modulated binary signal sidebands. The search pipeline…

General Relativity and Quantum Cosmology · Physics 2008-11-26 C. Messenger , G. Woan

Interpreting the spectral energy distributions (SEDs) of astrophysical objects with physically motivated models is computationally expensive. These models require solving coupled differential equations in high-dimensional parameter spaces,…

Radio-loud sources with blazar-like properties, but having a jet that does not directly point in the direction of the observer are among the most interesting classes of gamma-ray emitters. These sources are known as Misaligned Active…

Astrophysics of Galaxies · Physics 2020-07-30 G. Chiaro , G. La Mura , A. Dominguez , S. Bisogni

We focus on the automated classification of eclipsing binary stars using deep learning methods to handle the vast data generated by large-scale photometric sky surveys. These surveys produce extensive datasets that are impractical for…

Solar and Stellar Astrophysics · Physics 2026-03-27 Bedri Keskin , Özgür Baştürk

Time-variable polarization is an extremely valuable observational tool to probe the dynamical physical conditions of blazar jets. Since 2008, we have been monitoring the flux and linear polarization of a sample of gamma-ray bright blazars…

High Energy Astrophysical Phenomena · Physics 2021-05-04 Alan P. Marscher , Svetlana G. Jorstad

The study of the hard (E>10 keV) energy spectra of X-ray binary pulsars can give a wealth of information on the physical processes that occur close to the neutron star surface. Extreme matter regimes are probed, and precious information on…

Astrophysics · Physics 2007-05-23 Mauro Orlandini

Transient radio sources are necessarily compact and usually are the locations of explosive or dynamic events, therefore offering unique opportunities for probing fundamental physics and astrophysics. In addition, short-duration transients…

Astrophysics · Physics 2009-11-10 James M. Cordes , T. Joseph W. Lazio , M. A. McLaughlin

X-ray polarimetry promises us an unprecedented look at the structure of magnetic fields and on the processes at the base of acceleration of particles up to ultrarelativistic energies in relativistic jets. Crucial pieces of information are…

High Energy Astrophysical Phenomena · Physics 2021-05-19 Fabrizio Tavecchio

We describe our programme to identify and analyse binary stars among the bright subdwarfs selected in the Galaxy Evolution Explorer (GALEX) survey. Radial velocity time-series helped us identify subdwarfs with low-mass or compact stellar…

The use of Bayesian neural networks is a novel approach for the classification of gamma-ray sources. We focus on the classification of Fermi-LAT blazar candidates, which can be divided into BL Lacertae objects and Flat Spectrum Radio…

High Energy Astrophysical Phenomena · Physics 2022-05-13 Anja Butter , Thorben Finke , Felicitas Keil , Michael Krämer , Silvia Manconi

Gamma-ray bursts provide what is probably one of the messiest of all astrophysical data sets. Burst class properties are indistinct, as overlapping characteristics of individual bursts are convolved with effects of instrumental and sampling…

We present the first results from the new Survey of Extragalactic Nuclear Spectral Energies (SENSE) sample of "blazars". The sample has been chosen with minimal selection effects and is therefore ideal to probe the intrinsic properties of…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-06 J. A. Gupta , I. W. A. Browne , B. M. Pazderska

This paper overviews two interdependent issues important for mining remote sensing data (e.g. images) obtained from atmospheric monitoring missions. The first issue relates the building new public datasets and benchmarks, which are hot…

Computer Vision and Pattern Recognition · Computer Science 2021-06-29 Chaabane Djeraba , Jérôme Riedi

Aims. High Synchrotron Peaked blazars (HSPs) dominate the -ray sky at energies larger than a few GeV; however, only a few hundred blazars of this type have been catalogued so far. In this paper we present the 2WHSP sample, the largest and…

High Energy Astrophysical Phenomena · Physics 2017-01-25 Yu-Ling Chang , Bruno Arsioli , Paolo Giommi , Paolo Padovani

At energies ~>2 keV, active galactic nuclei (AGN) are the source of the cosmic X-ray background (CXB). For AGN population synthesis models to replicate the peak region of the CXB (~30 keV), a highly obscured and therefore nearly invisible…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 A. R. Draper , D. R. Ballantyne

Blazars, radio-loud active galactic nuclei with the relativistic jet closely aligned with the line of sight, dominate the extragalactic sky observed at gamma-ray energies, above 100 MeV. We discuss some of the emission properties of these…

High Energy Astrophysical Phenomena · Physics 2016-05-25 F. Tavecchio