Now showing items 1-7 of 7

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

(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 ﻿

(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 ...
• #### Event-Horizon-Scale Structure in the Supermassive Black Hole Candidate at the Galactic Centre ﻿

(Nature Publishing Group, 2008)
The cores of most galaxies are thought to harbour supermassive black holes, which power galactic nuclei by converting the gravitational energy of accreting matter into radiation. Sagittarius A* (Sgr A*), the compact source ...
• #### Fine-Scale Structure of the Quasar 3C 279 Measured with 1.3 mm Very Long Baseline Interferometry ﻿

(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, ...
• #### Interferometric Observation of the Highly Polarized SiO Maser Emission from the v = 1, J = 5-4 Transition Associated with VY Canis Majoris ﻿

(IOP Publishing, 2004)
We used the Submillimeter Array to image the SiO maser emission in the v = 1, J = 5−4 transition associated with the peculiar red supergiant VY Canis Majoris. We identified seven maser components and measured their relative ...
• #### Resolved magnetic-field structure and variability near the event horizon of Sagittarius A ﻿

(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 ...
• #### Submillimeter Array Imaging of the Maser Emission from the $H30\alpha$ Radio Recombination Line in MWC 349A ﻿

(American Astronomical Society, 2008)
We used the Submillimeter Array to map the angular distribution of the H30α recombination line (231.9 GHz) in the circumstellar region of the peculiar star MWC 349A. The resolution was 1.2'', but because of high signal-to-noise ...