Mark A Gurwell

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Approximately 10% of active galactic nuclei exhibit relativistic jets, which are powered by the accretion of matter onto supermassive black holes. Although the measured width profiles of such jets on large scales agree with theories of magnetic collimation, the predicted structure on accretion disk scales at the jet launch point has not been detected. We(More)
Executive Summary " How Does Venus atmosphere work? " A dedicated and renewed exploration effort is required to address this fundamental question. Key questions requiring new observations include: How did Venus' atmospheric runaway greenhouse evolve? What drives Venus' atmospheric super-rotation? What is the dynamical structure of the atmosphere from the(More)
  • Satoki Matsushita, Daisuke Iono, Glen R Petitpas, Richard C, Y Chou, Mark A Gurwell +9 others
  • 2008
We have used the Submillimeter Array (SMA) to make the first interferometric observations (beam size ∼ 1 ′′ , or ∼ 400 pc) of the 12 CO J=6-5 line and 435 µm (690 GHz) continuum emission toward the central region (half power field of view 17 ′′) of the nearby ultra-luminous infrared galaxy (ULIRG) Arp 220. These observations resolve the eastern and western(More)
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 rise to the observed synchrotron emission in galaxy cores and to the formation of relativistic jets, but no observations to date have been(More)
We present multi-wavelength studies of the radio galaxy 3C 120 and the blazar CTA 102 during unprecedented γ-ray flares for both sources. In both studies the analysis of γ-ray data has been compared with a series of 43 GHz VLBA images from the VLBA-BU-BLAZAR program, providing the necessary spatial resolution to probe the parsec scale jet evolution during(More)
  • Joshua D Younger, Giovanni G Fazio, Jia-Sheng Huang, Min S Yun, Grant W Wilson, Matthew L N Ashby +11 others
  • 2009
We present results from a continuing interferometric survey of high-redshift submillimeter galaxies with the Submillimeter Array, including high-resolution (beam size ∼ 2 arcsec) imaging of eight additional AzTEC 1.1mm selected sources in the COSMOS Field, for which we obtain six reliable (peak S/N > 5 or peak S/N > 4 with multiwavelength counterparts(More)
  • Joshua D Younger, Giovanni G Fazio, Jia, Sheng Huang, Min S Yun, Grant W Wilson +24 others
  • 2008
We have used the Submillimeter Array to image a flux limited sample of seven submillimeter galaxies, selected by the AzTEC camera on the JCMT at 1.1 mm, in the COSMOS field at 890 µm with ∼ 2 ′′ resolution. All of the sources – two radio–bright and five radio–dim – are detected as single point–sources at high significance (> 6σ), with positions accurate to(More)
The eSMA (" extended SMA ") combines the SMA, JCMT and CSO into a single facility, providing enhanced sensitivity and spatial resolution owing to the increased collecting area at the longest baselines. Until ALMA early science observing (2011), the eSMA will be the facility capable of the highest angular resolution observations at 345 GHz. The gain in(More)
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