Now showing items 1-9 of 9

    • FERMI LARGE AREA TELESCOPE DETECTION OF GRAVITATIONAL LENS DELAYED γ-RAY FLARES FROM BLAZAR B0218+357 

      Cheung, C. C.; Larsson, S.; Scargle, J. D.; Amin, M. A.; Blandford, R. D.; Bulmash, D.; Chiang, J.; Ciprini, S.; Corbet, R. H. D.; Falco, E. E.; Marshall, P. J.; Wood, D. L.; Ajello, M.; Bastieri, D.; Chekhtman, A.; D'Ammando, F.; Giroletti, M.; Grove, J. E.; Lott, B.; Ojha, R.; Orienti, M.; Perkins, J. S.; Razzano, M.; Smith, A. W.; Thompson, D. J.; Wood, K. S. (IOP, 2014-01-30)
      Using data from the Fermi Large Area Telescope (LAT), we report the first clear γ-ray measurement of a delay between flares from the gravitationally lensed images of a blazar. The delay was detected in B0218+357, a known ...
    • Fermi LAT Detection of a New Gamma-ray Source 4C +50.11 

      Carpenter, B.; Ojha, R.; D'Ammando, F.; Orienti, M.; Cheung, C. C. (The Astronomer's Telegram, 2014-01-31)
    • Multi-Physics of AGN Jets in the Multi-Messenger Era 

      Rani, B.; Petropoulou, M.; Zhang, H.; D'Ammando, F.; Finke, J.; Baring, M.; Böttcher, M.; Dimitrakoudis, S.; Gan, Z.; Giannios, D.; Hartmann, D. H.; Krichbaum, T. P.; Marscher, A. P.; Mastichiadis, A.; Nalewajko, K.; Ojha, R.; Paneque, D.; Shrader, C.; Sironi, L.; Tchekhovskoy, A.; Thompson, D. J.; Vlahakis, N.; Venters, T. M. (2019-03-11)
      Active galactic nuclei (AGN) with relativistic jets, powered by gas accretion onto their central supermassive black hole (SMBH), are unique laboratories for studying the physics of matter and elementary particles in extreme ...
    • Neutrinos, Cosmic Rays and the MeV Band 

      Ojha, R.; Zhang, H.; Kadler, M.; Neilson, N. K.; Kreter, M.; McEnery, J.; Buson, S.; Caputo, R.; Coppi, P.; D'Ammando, F.; Angelis, A. De; Fang, K.; Giannios, D.; Guiriec, S.; Guo, F.; Kopp, J.; Krauss, F.; Li, H.; Meyer, M.; Moiseev, A.; Petropoulou, M.; Prescod-Weinstein, C.; Rani, B.; Shrader, C.; Venters, T.; Wadiasingh, Z. (2019-03-13)
      The possible association of the blazar TXS 0506+056 with a high-energy neutrino detected by IceCube holds the tantalizing potential to answer three astrophysical questions: 1. Where do high-energy neutrinos originate? 2. ...
    • PKS 2123−463: a confirmed γ-ray blazar at high redshift 

      D'Ammando, F.; Rau, A.; Schady, P.; Finke, J.; Orienti, M.; Greiner, J.; Kann, D. A.; Ojha, R.; Foley, A. R.; Stevens, J.; Blanchard, J. M.; Edwards, P. G.; Kadler, M.; Lovell, J. E. J. (Oxford University Press, 2012-11-21)
      The flat spectrum radio quasar (FSRQ) PKS 2123−463 was associated in the first Fermi-Large Area Telescope (LAT) source catalogue with the γ-ray source 1FGL J2126.1−4603, but when considering the full first two years of ...
    • Radio follow-up of the γ-ray flaring gravitational lens JVAS B0218+357 

      Spingola, C.; Dallacasa, D.; Orienti, M.; Giroletti, M.; J. P. McKean; Cheung, C. C.; Hovatta, T.; Ciprini, S.; D'Ammando, F.; Falco, E.; Larsson, S.; Max-Moerbeck, W.; Ojha, R.; Readhead, A. C. S.; Richards, J. L.; Scargle, J. (Oxford University Press, 2016-02-10)
      We present results on multifrequency Very Long Baseline Array (VLBA) monitoring observations of the double-image gravitationally lensed blazar JVAS B0218+357. Multi-epoch observations started less than one month after the ...
    • Radio–gamma-ray connection and spectral evolution in 4C +49.22 (S4 1150+49): the Fermi, Swift and Planck view 

      Cutini, S.; Ciprini, S.; Orienti, M.; Tramacere, A.; D'Ammando, F.; Verrecchia, F.; Polenta, G.; Carrasco, L.; D'Elia, V.; Giommi, P.; González-Nuevo, J.; Grandi, P.; Harrison, D.; Hays, E.; Larsson, S.; Lähteenmäki, A.; León-Tavares, J.; López-Caniego, M.; Natoli, P.; Ojha, R.; Partridge, B.; Porras, A.; Reyes, L.; Recillas, E.; Torresi, E. (Oxford University Press, 2014-11-07)
      The Large Area Telescope on board the Fermi Gamma-ray Space Telescope detected a strong γ-ray flare on 2011 May 15 from a source identified as 4C +49.22, a flat spectrum radio quasar (FSRQ) also known as S4 1150+49. This ...
    • Swift follow-up of the flaring NLSy1 PKS 2004-447 

      D'Ammando, F.; Gokus, A.; Kadler, M.; Ojha, R.; Fermi Large Area Telescope Collaboration (2019-10-28)
    • Unusual flaring activity in the blazar PKS 1424−418 during 2008−2011 

      Buson, S.; Longo, F.; Larsson, S.; Cutini, S.; Finke, J.; Ciprini, S.; Ojha, R.; D'Ammando, F.; Donato, D.; Thompson, D. J.; Desiante, R.; Bastieri, D.; Wagner, S.; Hauser, M.; Fuhrmann, L.; Dutka, M.; Müller, C.; Kadler, M.; Angelakis, E.; Zensus, J. A.; Stevens, J.; Blanchard, J. M.; Edwards, P. G.; Lovell, J. E. J.; Gurwell, M. A.; Wehrle, A. E.; Zook, A. (EDP sciences, 2014-09-16)
      Context. Blazars are a subset of active galactic nuclei (AGN) with jets that are oriented along our line of sight. Variability and spectral energy distribution (SED) studies are crucial tools for understanding the physical ...