Browsing by Author "Marscher, A.P."

Now showing items 1-11 of 11

    • Detection of Gamma Rays with E > 100 MeV from BL Lacertae 

      Catanese, M.; Akerlof, C.; Biller, S.D.; Boyle, P.; Buckley, J.H.; Carter-Lewis, D.A.; Cawley, M.F.; Connaughton, V.; Dingus, B.; Fegan, D.J.; Fichtel, C.E.; Finley, J.P.; Gaidos, J.A.; Gear, W.K.; Hartman, R.C.; Hillas, A.M.; Krennrich, F.; Lamb, R.C.; Lessard, R.W.; Lin, Y.C.; McEnery, J.E.; Marscher, A.P.; Mohanty, G.; Mukherjee, R.; Quinn, J.; Robson, E.I.; Rodgers, A.J.; Rose, H.J.; Samuelson, F.W.; Sembroski, G.; Schubnell, M.S.; Stevens, J. A.; Terasranta, H.; Thompson, D.J.; Weekes, T.C.; Wilson, C.; Zweerink, J. (1997)

    • Discovery of a precessing jet nozzle in BL Lacertae 

      Stirling, A.M.; Cawthorne, T.V.; Stevens, J. A.; Jorstad, S.G.; Marscher, A.P.; Lister, M.; Gomez, J-L.; Smith, P.S.; Agudo, I.; Gabuzda, D.; Robson, E.I.; Gear, W.K. (2003)

    • High Energy Gamma Radiation From PKS 0528+134 Observed by EGRET 

      Mukherjee, R.; Gear, W.K.; Marscher, A.P.; Moore, E.M.; Travis, J.P.; Zhang, Y.; Robson, E.I.; Stevens, J. A.; Terasranta, H.; Tornikoski, M.; Wagner, S. (Astronomical Society of the Pacific, 1996)
      A summary of EGRET observations of PKS 0528+134 is given, with special emphasis on the 1993 March observations when the source flared in gamma-rays. The flux history of PKS 0528+134 as well as spectra of the source are ...

    • Jet Kinematics of AGNs at High Radio Frequencies 

      Jorstad, S.G.; Marscher, A.P.; Lister, M.; Stirling, A.M.; Cawthorne, T.V.; Gomez, J-L.; Gear, W.K.; Stevens, J. A.; Robson, E.I.; Smith, P.S.; Forster, J.R. (Astronomical Society of the Pacific, 2006)
      We have completed a 3 yr program of polarization monitoring of 15 active galactic nuclei with the Very Long Baseline Array at 7 mm wavelength. At some epochs the images are accompanied by nearly simultaneous polarization ...

    • Multi-frequency Polarization Properties of Blazars 

      Jorstad, S.G.; Marscher, A.P.; Stevens, J. A.; Robson, E.I.; Lister, M.; Stirling, A.M.; Smith, P.S.; Cawthorne, T.V.; Gomez, J-L.; Gabuzda, D.; Gear, W.K. (Astronomical Society of the Pacific, 2005)
      We have obtained total and polarized intensity images of 15 AGNs with the VLBA at 7 mm at 17 epochs, accompanied at many epochs by nearly simultaneous measurements of polarization at 1.35/0.85 mm and at optical wavelengths. ...

    • Multiwaveband polarimetric observations of 15 active galactic nuclei at high frequencies: correlated polarization behaviour 

      Jorstad, S.G.; Marscher, A.P.; Stevens, J. A.; Smith, P.S.; Forster, J.R.; Gear, W.K.; Cawthorne, T.V.; Lister, M.; Stirling, A.M.; Gomez, J-L.; Greaves, J.S.; Robson, E.I. (2007)

    • Multiwavelength Observations of a Dramatic High-Energy Flare in the Blazar 3C 279 

      Wehrle, A. E.; Pian, E.; Urry, C.M.; Maraschi, L.; McHardy, I.M.; Lawson, A.J.; Ghisellini, G.; Hartman, R.C.; Madejski, G.M.; Makino, F.; Marscher, A.P.; Wagner, S.J.; Webb, J.R.; Aldering, G.S.; Aller, M.F.; Aller, H.D.; Backman, D.E.; Balonek, T.J.; Boltwood, P.; Bonnell, J.; Caplinger, J.; Celotti, A.; Collmar, W.; Dalton, J.; Drucker, A.; Falomo, R.; Fichtel, C.E.; Freudling, W.; Gear, W.K.; Gonzalez-Perez, N.; Hall, P.; Inoue, H.; Johnson, W.N.; Kazanas, D.; Kidger, M.R.; Kii, T.; Kollgaard, R.I.; Kondo, Y.; Kurfess, J.; Lin, Y.C.; McCollum, B.; McNaron-Brown, K.; Nagase, F.; Nair, A.D.; Penton, S.; Pesce, J.E.; Pohl, M.; Raiteri, C.M.; Renda, M.; Robson, E.I.; Sambruna, R.M.; Schirmer, A.F.; Shrader, C.; Sikora, M.; Sillanpaeae, A.; Smith, P.S.; Stevens, Jason; Stocke, J.; Takalo, L.O.; Teraesranta, H.; Thompson, D.J.; Thompson, R.; Tornikoski, M.; Tosti, G.; Treves, A.; Turcotte, P.; Unwin, S.C.; Valtaoja, E.; Villata, M.; Xu, W.; Yamashita, A.; Zook, A. (1998-04-01)
      The blazar 3C 279, one of the brightest identified extragalactic objects in the γ-ray sky, underwent a large (factor of ~10 in amplitude) flare in γ-rays toward the end of a 3 week pointing by Compton Gamma Ray Observatory ...

    • Multiwavelength observations of the February 1996 high-energy flare in the blazar 3C 279 

      Wehrle, A. E.; Pian, E.; Urry, C.M.; Maraschi, L.; Ghisellini, G.; Hartman, R.C.; Madejski, G. M.; Makino, F.; Marscher, A.P.; McHardy, I.M.; Webb, J. R.; Aldering, G. S.; Aller, M. F.; Aller, H. D.; Backman, D.E.; Balonek, T.J.; Boltwood, P.; Bonnell, J.; Caplinger, J.; Celotti, A.; Collmar, W.; Dalton, J.; Drucker, A.; Falomo, R.; Fichtel, C.E.; Freudling, W.; Gear, W.K.; Gonzalez-Perez, N.; Hall, P.; Inoue, H.; Johnson, W. N.; Kidger, M. R.; Kollgaard, R. I.; Kondo, Y.; Kurfess, J.; Lawson, A.J.; McCollum, B.; McNaron-Brown, K.; Nair, D.; Penton, S.; Pesce, J. E.; Pohl, M.; Raiteri, C.M.; Renda, M.; Robson, E.I.; Sambruna, R.M.; Schirmer, A. F.; Shrader, C.; Sikora, M.; Sillanpää, A.; Smith, P.S.; Stevens, Jason; Stocke, J.; Takalo, L.O.; Teräsranta, H.; Thompson, D.J.; Thompson, R.; Tornikoski, M.; Tosti, G.; Turcotte, P.; Treves, A.; Unwin, S.C.; Valtaoja, E.; Villata, M.; Wagner, S.J.; Xu, W.; Zook, A. C. (American Institute of Physics (AIP), 1997-05-01)
      We report CGRO, RXTE, ASCA, ROSAT, IUE, HST and ground-based observations of a large flare in 3C 279 in February 1996. X-rays and γ-rays peaked simultaneously (within one day). We show simultaneous spectral energy distributions ...

    • Polarimetric Observations of 15 Active Galactic Nuclei at High Frequencies: Jet Kinematics from Bimonthly Monitoring with the very Long Baseline Array 

      Marscher, A.P.; Jorstad, S.G.; Lister, M.; Stirling, A.M.; Cawthorne, T.V.; Gear, W.K.; Gomez, J-L.; Stevens, J. A.; Smith, P.S.; Forster, J.R.; Robson, E.I. (2005-10)

    • Polarimetric Observations of 15 AGNs at High Frequencies 

      Jorstad, S.G.; Marscher, A.P.; Stevens, J. A.; Robson, I.; Lister, M.; Stirling, A.M.; Cawthorne, T.V.; Smith, P.S.; Gomez, J-L.; Gabuzda, D.; Gear, W.K. (Astronomical Society of the Pacific, 2005)
      We have obtained total and polarized intensity images of 15 AGNs with the VLBA at 7 mm at 17 epochs from 25/26 March 1998 to 14 April 2001. The VLBA observations are accompanied at many epochs by simultaneous mea- surements ...

    • Simultaneous X-ray and IR variability in the quasar 3C 273 

      Hardy, I.M.; Lawson, A.; Newsam, A.; Marscher, A.P.; Robson, I.; Stevens, J. A. (1999)
      From a combination of high quality X-ray observations from the NASA Rossi X-ray Timing Explorer (RXTE), and infrared observations from the UK Infrared Telescope (UKIRT) we show that the medium energy X-ray (3-20 keV) and ...