A Discovery of Young Radio Sources in the Cores of Giant Radio Galaxies Selected at Hard X-Rays
Autor: | L. Hernández-García, Francesco Ursini, Alex Kraus, Daniele Dallacasa, Pietro Ubertini, Francesca Panessa, E. Chiaraluce, Gabriele Bruni, Tiziana Venturi, L. Bassani, Angela Bazzano, Angela Malizia |
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Přispěvatelé: | Bruni, G., Panessa, F., Bassani, L., Chiaraluce, E., Kraus, A., Dallacasa, D., Bazzano, A., Hernandez-Garcia, L., Malizia, A., Ubertini, P., Ursini, F., Venturi, T., Bruni G., Panessa F., Bassani L., Chiaraluce E., Kraus A., Dallacasa D., Bazzano A., Hernandez-Garcia L., Malizia A., Ubertini P., Ursini F., Venturi T. |
Rok vydání: | 2019 |
Předmět: |
010504 meteorology & atmospheric sciences
galaxies: jet Radio galaxy Astrophysics::High Energy Astrophysical Phenomena galaxies: active nuclei [galaxies] FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences 0103 physical sciences 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Physics Astronomy and Astrophysics Astrophysics - Astrophysics of Galaxies Accretion (astrophysics) galaxies [X-rays] X-rays: galaxies jet [galaxies] Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Hard X-rays active [galaxies] galaxie [radio continuum] galaxies: nuclei radio continuum: galaxie |
Zdroj: | The Astrophysical Journal |
ISSN: | 1538-4357 0004-6361 1538-3881 0004-637X 0067-0049 0726-3252 1538-3873 |
Popis: | Giant Radio Galaxies (GRG) are the largest single entities in the Universe, having a projected linear size exceeding 0.7 Mpc, which implies that they are also quite old objects. They are not common, representing a fraction of only about 6% in samples of bright radio galaxies. While a census of about 300 of these objects has been built in the past years, still no light has been shed on the conditions necessary to allow such an exceptional growth, whether of environmental nature or linked to the inner accretion properties. Recent studies found that samples of radio galaxies selected from hard X-ray AGN catalogs selected from INTEGRAL/IBIS and Swift/BAT (thus at energies >20 keV) present a fraction of GRG four times larger than what found in radio-selected samples. We present radio observations of 15 nuclei of hard X-ray selected GRG, finding for the first time a large fraction (61%) of young radio sources at the center of Mpc-scale structures. Being at the center of GRG, these young nuclei may be undergoing a restarting activity episode, suggesting a link between the detected hard X-ray emission - due to the ongoing accretion - and the reactivation of the jets. Accepted for publication on ApJ |
Databáze: | OpenAIRE |
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