Now showing items 1-18 of 18

    • ATCA monitoring of gamma-ray loud AGN 

      Stevens, J.; Edwards, P. G.; Ojha, R.; Kadler, M.; Hungwe, F.; Dutka, M.; Tingay, S.; Macquart, J. P.; Moin, A.; Lovell, J.; Blanchard, J. (2012-11-12)
      As a critical part of the Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry (TANAMI) program, in November 2007 the Australia Telescope Compact Array (ATCA) started monitoring the radio spectra of ...
    • 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 ...
    • The Gamma-Ray Blazar PKS 0208-512, a Multi-Wavelength Investigation 

      Blanchard, J. M.; Lovell, J. E. J.; Dickey, J.; Ojha, R.; Kadler, M.; Nesci, R.; Edwards, P. G.; Stevens, J.; Dutka, M.; Muller, C.; Pursimo, T. (2012-06-27)
      The gamma-ray blazar PKS 0208-512 has shown strong periods of flaring, at all frequencies from radio to gamma-ray. This has led to its inclusion in the TANAMI project, which tracks the jets of southern AGN using VLBI as ...
    • Gamma-ray emission in radio galaxies under the VLBI scope I. Parsec-scale jet kinematics and high-energy properties of γ-ray-detected TANAMI radio galaxies 

      Angioni, R.; Ros, E.; Kadler, M.; Ojha, R.; Müller, C.; Edwards, P. G.; Burd, P. R.; Carpenter, B.; Dutka, M. S.; Gulyaev, S.; Hase, H.; Horiuchi, S.; Krauß, F.; Lovell, J. E. J.; Natusch, T.; Phillips, C.; Plötz, C.; Quick, J. F. H.; Rösch, F.; Schulz, R.; Stevens, J.; Tzioumis, A. K.; Weston, S.; Wilms, J.; Zensus, J. A. (EDP sciences, 2019-07-15)
      Aims. In the framework of the multi-wavelength and very long baseline interferometry (VLBI) monitoring program TANAMI (Tracking Active Nuclei with Austral Milliarcsecond Interferometry), we study the evolution of the ...
    • The gamma-ray emitting radio-loud narrow-line Seyfert 1 galaxy PKS 2004−447 

      Schulz, R.; Kreikenbohm, A.; Kadler, M.; Ojha, R.; Ros, E.; Stevens, J.; Edwards, P. G.; Carpenter, B.; Elsässer, D.; Gehrels, N.; Grossberger, C.; Hase, H.; Horiuchi, S.; Lovell, J. E. J.; Mannheim, K.; Markowitz, A.; Müller, C.; Phillips, C.; Plötz, C.; Quick, J.; Trüstedt, J.; Tzioumis, A. K.; Wilms, J. (EDP sciences, 2016-04-01)
      Context. Γ-ray-detected radio-loud narrow-line Seyfert 1 (γ-NLS1) galaxies constitute a small but interesting sample of the γ-ray-loud AGN. The radio-loudest γ-NLS1 known, PKS 2004−447, is located in the southern hemisphere ...
    • High resolution rapid response observations of compact radio sources with the Ceduna Hobart Interferometer (CHI) 

      Blanchard, J. M.; Lovell, J. E. J.; Ojha, R.; Kadler, M.; Dickey, J. M.; Edwards, P. G. (EDP sciences, 2012-02-17)
      Context. Frequent, simultaneous observations across the electromagnetic spectrum are essential to the study of a range of astrophysical phenomena including active galactic nuclei. A key tool of such studies is the ability ...
    • HUNTING FOR TREASURES AMONG THE FERMI UNASSOCIATED SOURCES: A MULTIWAVELENGTH APPROACH 

      Acero, F.; Donato, D.; Ojha, R.; Stevens, J.; Edwards, P. G.; Ferrara, E.; J. Blanchard, J.; Lovell, J. E. J.; Thompson, D. J. (IOP, 2013-12-20)
      The Fermi Gamma-Ray Space Telescope has been detecting a wealth of sources where the multiwavelength counterpart is either inconclusive or missing altogether. We present a combination of factors that can be used to identify ...
    • 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 and gamma-ray properties of extragalactic jets from the TANAMI sample 

      Böck, M.; Kadler, M.; Müller, C.; Tosti, G.; Bastieri, D.; Burnett, T.; Carpenter, B.; Cavazzuti, E.; Dutka, M.; Blanchard, J.; Edwards, P. G.; Hase, H.; Horiuchi, S.; Jauncey, D. L.; Krauß, F.; Lister, M. L.; Lovell, J. E. J.; Lott, B.; Murphy, D. W.; Phillips, C.; Plötz, C.; Pursimo, T.; Quick, J.; Ros, E.; Taylor, G.; Thompson, D. J.; Tingay, S. J.; Tzioumis, A.; Zensus, J. A. (EDP sciences, 2016-05-04)
      The TANAMI program has been observing parsec-scale radio jets of southern (declination south of − 30°) γ-ray bright AGN, simultaneously with Fermi/LAT monitoring of their γ-ray emission, via high-resolution radio imaging ...
    • TANAMI - Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry 

      Muller, Cornelia; Kadler, Matthias; Ojha, Roopesh; Bock, M.; Booth, R.; Dutka, M. S.; Edwards, P. G.; Fey, A. L.; Fuhrmann, L.; Hase, H.; Horiuchi, S.; Hungwe, F.; Ros, E.; Taylor, G. B.; Thompson, D. J.; Tingay, S. J.; Tosti, G.; Tzioumis, A. K.; Wilms, J.; Zensus, J. A. (2010-01-18)
      We present a summary of the observation strategy of TANAMI (Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry), a monitoring program to study the parsec-scale structure and dynamics of relativistic ...
    • TANAMI blazars in the IceCube PeV-neutrino fields 

      Krauß, F.; Kadler, M.; Mannheim, K.; Schulz, R.; Trüstedt, J.; Wilms, J.; Ojha, R.; Ros, E.; Anton, G.; Baumgartner, W.; Beuchert, T.; Blanchard, J.; Bürkel, C.; Carpenter, B.; Eberl, T.; Edwards, P. G.; Eisenacher, D.; Elsässer, D.; Fehn, K.; Fritsch, U.; Gehrels, N.; Gräfe, C.; Grossberger, C.; Hase, H.; Horiuchi, S.; James, C.; Kappes, A.; Katz, U.; Kreikenbohm, A.; Kreykenbohm, I.; Langejahn, M.; Leiter, K.; Litzinger, E.; Lovell, J. E. J.; Müller, C.; Phillips, C.; Plötz, C.; Quick, J.; Steinbring, T.; Stevens, J.; Thompson, D. J.; Tzioumis, A. K. (EDP sciences, 2014-06-24)
      The IceCube Collaboration has announced the discovery of a neutrino flux in excess of the atmospheric background. Owing to the steeply falling atmospheric background spectrum, events at PeV energies most likely have an ...
    • TANAMI monitoring of Centaurus A: The complex dynamics in the inner parsec of an extragalactic jet 

      Müller, C.; Kadler, M.; Ojha, R.; Perucho, M.; Grossberger, C.; Ros, E.; Wilms, J.; Blanchard, J.; Böck, M.; Carpenter, B.; Dutka, M.; Edwards, P. G.; Hase, H.; Horiuchi, S.; Kreikenbohm, A.; Lovell, J. E. J.; Markowitz, A.; Phillips, C.; Plötz, C.; Pursimo, T.; Quick, J.; Rothschild, R.; Schulz, R.; Steinbring, T.; Stevens, J.; Trüstedt, J.; Tzioumis, A. K. (EDP sciences, 2014-10-01)
      Context. Centaurus A (Cen A) is the closest radio-loud active galactic nucleus. Very Long Baseline Interferometry (VLBI) enables us to study the spectral and kinematic behavior of the radio jet-counterjet system on ...
    • The TANAMI Multiwavelength Program: Dynamic spectral energy distributions of southern blazars 

      Krauß, F.; Wilms, J.; Kadler, M.; Ojha, R.; Schulz, R.; Trüstedt, J.; Edwards, P. G.; Stevens, J.; Ros, E.; Baumgartner, W.; Beuchert, T.; Blanchard, J.; Buson, S.; Carpenter, B.; Dauser, T.; Falkner, S.; Gehrels, N.; Graefe, C.; Gulyaev, S.; Hase, H.; Horiuchi, S.; Kreikenbohm, I.; Langejahn, M.; Leiter, K.; Lovell, J. E. J.; Müller, C.; Natusch, T.; Nesci, R.; Pursimo, T.; Phillips, C.; Plötz, C.; Quick, J.; Tzioumis, A. K.; Weston, S. (EDP sciences, 2018-03-03)
      Context. Simultaneous broadband spectral and temporal studies of blazars are an important tool for investigating active galactic nuclei (AGN) jet physics. Aims. We study the spectral evolution between quiescent and ...
    • TANAMI: Milliarcsecond Resolution Observations of Extragalactic Gamma-ray Sources 

      Ojha, Roopesh; Kadler, M.; Böck, M.; Booth, R.; Dutka, M. S.; Edwards, P. G.; Fey, A. L.; Fuhrmann, L.; Gaume, R. A.; Hase, H.; Horiuchi, S.; Jauncey, D.L.; Johnston, K. J.; Katz, U.; Lister, M.; Lovell, J. E. J.; Müller, C.; Plötz, C.; Quick, J. F. H.; Ros, E.; Taylor, G. B.; Thompson, D. J.; Tingay, S. J.; Tosti, G.; Tzioumis, A. K.; Wilms, J.; Zensus, J. A. (arXiv, 2009-12-31)
      The TANAMI (Tracking AGN with Austral Milliarcsecond Interferometry) and associated programs provide comprehensive radio monitoring of extragalactic gamma-ray sources south of declination -30 degrees. Joint quasi-simultaneous ...
    • TANAMI: tracking active galactic nuclei with austral milliarcsecond interferometry 

      Ojha, R.; Kadler, M.; Böck, M.; Booth, R.; Dutka, M. S.; Edwards, P. G.; Fey, A. L.; Fuhrmann, L.; Gaume, R. A.; Hase, H.; Horiuchi, S.; Jauncey, D. L.; Johnston, K. J.; Katz, U.; Lister, M.; Lovell, J. E. J.; Müller, C.; Plötz, C.; Quick, J. F. H.; Ros, E.; Taylor, G. B.; Thompson, D. J.; Tingay, S. J.; Tosti, G.; Tzioumis, A. K.; Wilms, J.; Zensus, J. A. (EDP sciences, 2010-09-10)
      Context. A number of theoretical models vie to explain the γ-ray emission from active galactic nuclei (AGN). This was a key discovery of EGRET. With its broader energy coverage, higher resolution, wider field of view and ...
    • TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry⋆ 

      Müller, C.; Kadler, M.; Ojha, R.; Schulz, R.; Trüstedt, J.; Edwards, P. G.; Ros, E.; Carpenter, B.; Angioni, R.; Blanchard, J.; Böck, M.; Burd, P. R.; Dörr, M.; Dutka, M. S.; Eberl, T.; Gulyaev, S.; Hase, H.; Horiuchi, S.; Katz, U.; Krauß, F.; Lovell, J. E. J.; Natusch, T.; Nesci, R.; Phillips, C.; Plötz, C.; Pursimo, T.; Quick, J. F. H.; Stevens, J.; Thompson, D. J.; Tingay, S. J.; Tzioumis, A. K.; Weston, S.; Wilms, J.; Zensus, J. A. (EDP sciences, 2018-02-07)
      Context. TANAMI is a multiwavelength program monitoring active galactic nuclei (AGN) south of − 30° declination including high-resolution very long baseline interferometry (VLBI) imaging, radio, optical/UV, X-ray, and γ-ray ...
    • 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 ...
    • The unusual multiwavelength properties of the gamma-ray source PMN J1603−4904 

      Müller, Cornelia; Kadler, M.; Ojha, R.; Böck, M.; Krauß, F.; Taylor, G. B.; Wilms, J.; Blanchard, J.; Carpenter, B.; Dauser, T.; Dutka, M.; Edwards, P. G.; Gehrels, N.; Grossberger, C.; Hase, H.; Horiuchi, S.; Kreikenbohm, A.; Lovell, J. E. J.; McConville, W.; Phillips, C.; Plötz, C.; Pursimo, T.; Quick, J.; Ros, E.; Schulz, R.; Stevens, J.; Tingay, S. J.; Trüstedt, J.; Tzioumis, A. K.; Zensus, J. A. (EDP sciences, 2014-01-30)
      Context. We investigate the nature and classification of PMN J1603−4904, a bright radio source close to the Galactic plane, which is associated with one of the brightest hard-spectrum γ-ray sources detected by Fermi/LAT. ...