• Fermi LAT detection of enhanced gamma-ray emission from the Crab Nebula region 

  Ojha, Roopesh; Buehler, Rolf; Hays, Elizabeth; Dutka, Michael (The Astronomer's Telegram, 2012-07-05)

• 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)

• Fermi LAT detection of a new gamma-ray flare from the Crab Nebula region 

  Ojha, Roopesh; Hays, Elizabeth; Buehler, Rolf; Dutka, Michael (The Astronomer's Telegram, 2013-03-04)

• Fermi LAT Detection of a GeV Flare from the Radio-Loud Narrow-Line Sy1 1H 0323+342 

  Carpenter, Bryce; Ojha, Roopesh (The Astronomer's Telegram, 2013-08-30)

• Fermi LAT Detection of a Gamma-ray Flare from the active galaxy PKS 0903-57 

  Carpenter, Bryce; Ojha, Roopesh (The Astronomer's Telegram, 2015-06-24)

• Fermi LAT detection of a GeV flare from the gravitationally lensed FSRQ PKS 1830-211 

  Krauss, F.; Ojha, R.; Buson, S. (The Astronomer's Telegram, 2014-08-02)

• FERMI LARGE AREA TELESCOPE VIEW OF THE CORE OF THE RADIO GALAXY CENTAURUS A 

  Çelik, Ö.; Davis, D. S.; Georganopoulos, M.; Ojha, R. (IOP, 2010-07-29)

  We present γ-ray observations with the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope of the nearby radio galaxy Centaurus A (Cen A). The previous EGRET detection is confirmed, and the localization ...

• 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 ...

• Extended X-ray emission in PKS 1718−649 

  Beuchert, T.; Rodríguez-Ardila, A.; Moss, V. A.; Schulz, R.; Kadler, M.; Wilms, J.; Angioni, R.; Callingham, J. R.; Gräfe, C.; Krauß, F.; Kreikenbohm, A.; Langejahn, M.; Leiter, K.; Maccagni, F. M.; Müller, C.; Ojha, R.; Ros, E.; Tingay, S. J. (EDP sciences, 2018-04-30)

  PKS 1718−649 is one of the closest and most comprehensively studied candidates of a young active galactic nucleus (AGN) that is still embedded in its optical host galaxy. The compact radio structure, with a maximal extent ...

• Enormous disc of cool gas surrounding the nearby powerful radio galaxy NGC 612 (PKS 0131−36) 

  Emonts, B. H. C.; Morganti, R.; Oosterloo, T. A.; Holt, J.; Tadhunter, C. N.; Van Der Hulst, J. M.; Ojha, R.; Sadler, E. M. (Oxford University Press, 2008-05-09)

  We present the detection of an enormous disc of cool neutral hydrogen (H I) gas surrounding the S0 galaxy NGC 612, which hosts one of the nearest powerful radio sources (PKS 0131−36). Using the Australia Telescope Compact ...

• Exceptional NIR flare in gamma-ray loud FSRQ PKS B1424-418 

  Nesci, R.; Ojha, R.; Kadler, M. (2015-01-26)

  The gamma-ray loud flat spectrum radio quasar PKS 1424-418 has been steadily increasing its luminosity since August 2017 and is now (2018-01-21) at its historic recorded maximum of J=13.73 +/- 0.05. These observations were ...

• Energetic Particles of Cosmic Accelerators II: Active Galactic Nuclei and Gamma-ray Bursts 

  Venters, Tonia M.; Guiriec, Sylvain; Lien, Amy Y.; Ojha, Roopesh

  The high-energy universe has revealed that energetic particles are ubiquitous in the cosmos and play a vital role in the cultivation of cosmic environments on all scales. Our pursuit of more than a century to uncover the ...

• Energetic Particles of Cosmic Accelerators I: Galactic Accelerators 

  Venters, Tonia M.; Hamaguchi, Kenji; Ojha, Roopesh

  The high-energy universe has revealed that energetic particles are ubiquitous in the cosmos and play a vital role in the cultivation of cosmic environments on all scales. Our pursuit of more than a century to uncover the ...

• Dual-frequency VLBI study of Centaurus A on sub-parsec scales. The highest-resolution view of an extragalactic jet 

  Müller, C.; Kadler, M.; Ojha, R.; Wilms, J.; Böck, M.; Edwards, P. G.; Fromm, C. M.; Hase, H.; Horiuchi, S.; Katz, U.; Lovell, J. E. J.; Plötz, C.; Pursimo, T.; Richers, S.; Ros, E.; Rothschild, R. E.; Taylor, G. B.; Tingay, S. J.; Zensus, J. A. (EDP sciences, 2011-05-20)

  Context. Centaurus A is the closest active galactic nucleus. High resolution imaging using Very Long Baseline Interferometry (VLBI) enables us to study the spectral and kinematic behavior of the radio jet–counterjet system ...

• DUAL-FREQUENCY OBSERVATIONS OF 140 COMPACT, FLAT-SPECTRUM ACTIVE GALACTIC NUCLEI FOR SCINTILLATION-INDUCED VARIABILITY 

  Koay, J. Y.; Macquart, J.-P.; Rickett, B. J.; Bignall, H. E.; Lovell, J. E. J.; Reynolds, C.; Jauncey, D. L.; Pursimo, T.; Kedziora-Chudczer, L.; Ojha, R. (IOP, 2011-08-30)

  The 4.9 GHz Micro-Arcsecond Scintillation-Induced Variability (MASIV) Survey detected a drop in interstellar scintillation (ISS) for sources at redshifts z gsim 2, indicating an apparent increase in angular diameter or a ...

• Detection of the blazar S4 0954+65 at very-high-energy with the MAGIC telescopes during an exceptionally high optical state 

  González, J. Becerra; Ojha, R. (EDP sciences, 2018-09-13)

  Aims. The very high energy (VHE ≳100 GeV) γ-ray MAGIC observations of the blazar S4 0954+65, were triggered by an exceptionally high flux state of emission in the optical. This blazar has a disputed redshift of z = 0.368 ...

• Detection of a Gamma-Ray Flare from the High-redshift Blazar DA 193 

  Paliya, Vaidehi S.; Ajello, M.; Ojha, R.; Angioni, R.; Cheung, C. C.; Tanada, K.; Pursimo, T.; Galindo, P.; Losada, I. R.; Siltala, L.; Djupvik, A. A.; Marcotulli, L.; Hartmann, D. (IOP, 2019-02-01)

  High-redshift (z > 2) blazars are the most powerful members of the blazar family. Yet, only a handful of them have both X-ray and γ-ray detection, thereby making it difficult to characterize the energetics of the most ...

• Consequences of a possible jet-star interaction in the inner central parsec of Centaurus A 

  Müller, C.; Kadler, M.; Mannheim, K.; Perucho, M.; Ojha, R.; Ros, E.; Schulza, R.; Wilms, J.

  The jet-counterjet system of the closest radio-loud active galaxy Centaurus A (Cen A) can be studied with Very Long Baseline Interferometry (VLBI) on unprecedented small linear scales of ∼ 0.018 pc. These high-resolution ...

• Compton-Pair Production Space Telescope (ComPair) for MeV Gamma-ray Astronomy 

  Moiseev, A.A.; Ajello, M.; Buckley, J.H.; Caputo, R.; Ferrara, E.C.; Hartmann, D.H.; Hays, E.; McEnery, J.E.; Mitchell, J.W.; Ojha, R.; Perkins, J.S.; Racusin, J.L.; Smith, A.W.; Thompson, D.J. (2015-09-18)

  The gamma-ray energy range from a few hundred keV to a few hundred MeV has remained largely unexplored, mainly due to the challenging nature of the measurements, since the pi- oneering, but limited, observations by COMPTEL ...

• Characterization of long baseline calibrators at 2.3 GHz 

  Hungwe, F.; Ojha, R.; Booth, R. S.; Bietenholz, M. F.; Collioud, A.; Charlot, P.; Boboltz, D.; Fey, A. L. (Oxford University Press, 2011-12-08)

  We present a detailed multi-epoch analysis of 31 potential Southern hemisphere radio calibrators that were originally observed as part of a programme to maintain the International Celestial Reference Frame. At radio ...

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