Now showing items 1-5 of 5

    • 1.3 mm Wavelength VLBI of Sagittarius A*: Detection of Time-Variable Emission on Event Horizon Scales 

      Fish, Vincent L.; Doeleman, Sheperd Samuel; Beaudoin, Christopher; Blundell, Raymond; Bolin, David E.; Bower, Geoffrey C.; Chamberlin, Richard; Freund, Robert; Friberg, Per; Gurwell, Mark Andrew; Honma, Mareki; Inoue, Makoto; Krichbaum, Thomas P.; Lamb, James; Marrone, Daniel P.; Moran, James M.; Oyama, Tomoaki; Plambeck, Richard; Primiani, Rurik A.; Rogers, Alan E. E.; Smythe, Daniel L.; SooHoo, Jason; Strittmatter, Peter; Tilanus, Remo P. J.; Titus, Michael; Weintroub, Jonathan; Wright, Melvyn; Woody, David; Young, Ken Harbour; Ziurys, Lucy M. (IOP Publishing, 2011)
      Sagittarius A*, the ~4 × 106 M ☉ black hole candidate at the Galactic center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength very long baseline interferometry (VLBI). We report on 1.3 mm ...
    • 230 GHz VLBI observations of M87: event-horizon-scale structure at the enhanced very-high-energy γ-ray state in 2012 

      Akiyama, Kazunori; Lu, Ru-Sen; Fish, Vincent; Doeleman, Sheperd S.; Broderick, Avery; Dexter, Jason; Hada, Kazuhiro; Kino, Motoki; Nagai, Hiroshi; Honma, Mareki; Johnson, Michael D.; Algaba, Juan; Asada, Keiichi; Brinkerink, Christiaan; Blundell, Raymond; Bower, Geoffrey; Cappallo, Roger; Crew, Geoffrey; Dexter, Matt; Dzib, Sergio; Freund, Robert; Friberg, Per; Gurwell, Mark Andrew; Ho, Paul; Inoue, Makoto; Krichbaum, Thomas; Loinard, Laurent; MacMahon, David; Marrone, Daniel; Moran, James M.; Nakamura, Masanori; Nagar, Neil; Ortiz-Leon, Gisela; Plambeck, Richard; Pradel, Nicolas; Primiani, Rurik A.; Rogers, Alan; Roy, Alan; SooHoo, Jason; Tavares, Jonathan-León; Tilanus, Remo; Titus, Michael; Wagner, Jan; Weintroub, Jonathan; Yamaguchi, Paul Isami; Young, Ken Harbour; Zensus, Anton; Ziurys, Lucy (IOP Publishing, 2015)
      We report on 230 GHz (1.3 mm) VLBI observations of M87 with the Event Horizon Telescope using antennas on Mauna Kea in Hawaii, Mt. Graham in Arizona and Cedar Flat in California. For the first time, we have acquired 230 ...
    • Fine-Scale Structure of the Quasar 3C 279 Measured with 1.3 mm Very Long Baseline Interferometry 

      Lu, Ru-Sen; Fish, Vincent L.; Akiyama, Kazunori; Doeleman, Sheperd S.; Algaba, Juan C.; Bower, Geoffrey C.; Brinkerink, Christiaan; Chamberlin, Richard; Crew, Geoffrey; Cappallo, Roger J.; Dexter, Matt; Freund, Robert; Friberg, Per; Gurwell, Mark Andrew; Ho, Paul T. P.; Honma, Mareki; Inoue, Makoto; Jorstad, Svetlana G.; Krichbaum, Thomas P.; Loinard, Laurent; MacMahon, David; Marrone, Daniel P.; Marscher, Alan P.; Moran, James M.; Plambeck, Richard; Pradel, Nicolas; Primiani, Rurik A.; Tilanus, Remo P. J.; Titus, Michael; Weintroub, Jonathan; Wright, Melvyn; Young, Ken Harbour; Ziurys, Lucy M. (American Astronomical Society, 2013)
      We report results from five day very long baseline interferometry observations of the well-known quasar 3C 279 at 1.3mm (230 GHz) in 2011. The measured nonzero closure phases on triangles including stations in Arizona, ...
    • Jet-Launching Structure Resolved Near the Supermassive Black Hole in M87 

      Doeleman, Sheperd Samuel; Fish, V. L.; Schenck, D. E.; Beaudoin, C.; Blundell, Raymond; Bower, G. C.; Broderick, Alithia Carol; Chamberlin, R.; Freund, R.; Friberg, P.; Gurwell, Mark Andrew; Ho, Po-Yi; Honma, M.; Inoue, M.; Krichbaum, T. P.; Lamb, J; Loeb, Abraham; Lonsdale, C.; Marrone, D. P.; Moran, James M.; Oyama, T.; Plambeck, R.; Primiani, Rurik A.; Rogers, A. E. E.; Smythe, D. L.; SooHoo, J.; Strittmatter, P.; Tilanus, R. P. J.; Titus, M.; Weintroub, Jonathan; Wright, Bennett Bennett; Young, K. H.; Ziurys, L. M. (American Association for the Advancement of Science (AAAS), 2012)
      Approximately 10% of active galactic nuclei exhibit relativistic jets, which are powered by accretion of matter onto super massive black holes. While the measured width profiles of such jets on large scales agree with ...
    • Resolved magnetic-field structure and variability near the event horizon of Sagittarius A 

      Johnson, Michael D.; Fish, V. L.; Doeleman, Sheperd S.; Marrone, D. P.; Plambeck, R. L.; Wardle, J. F. C.; Akiyama, K.; Asada, K.; Beaudoin, C.; Blackburn, Lindy; Blundell, Raymond; Bower, G. C.; Brinkerink, C.; Broderick, A. E.; Cappallo, R.; Chael, Andrew Alan; Crew, G. B.; Dexter, J.; Dexter, M.; Freund, R.; Friberg, P.; Gold, R.; Gurwell, M. A.; Ho, P. T. P.; Honma, M.; Inoue, M.; Kosowsky, Michael Steven; Krichbaum, T. P.; Lamb, J.; Loeb, Abraham; Lu, R.-S.; MacMahon, D.; McKinney, J. C.; Moran, James M.; Narayan, Ramesh; Primiani, Rurik A.; Psaltis, D.; Rogers, A. E. E.; Rosenfeld, Katherine Ann; SooHoo, J.; Tilanus, R. P. J.; Titus, M.; Vertatschitsch, L.; Weintroub, Jonathan; Wright, M.; Young, Ken Harbour; Zensus, J. A.; Ziurys, L. M. (American Association for the Advancement of Science (AAAS), 2015)
      Near a black hole, differential rotation of a magnetized accretion disk is thought to produce an instability that amplifies weak magnetic fields, driving accretion and outflow. These magnetic fields would naturally give ...