Detecting Changing Polarization Structures in Sagittarius A* with High Frequency VLBI (2009)
Fish, Vincent L., Doeleman, Sheperd S., Broderick, Avery E., Loeb, Abraham, Rogers, Alan E. E.
Sagittarius A* is the source of near infrared, X-ray, radio, and (sub)millimeter emission associated with the supermassive black hole at the Galactic Center. In the submillimeter regime, Sgr A*...
Imaging an Event Horizon: submm-VLBI of a Super Massive Black Hole (2009)
Doeleman, Sheperd, Agol, Eric, Backer, Don, Baganoff, Fred, Bower, Geoffrey C., Broderick, Avery, ...
A long standing goal in astrophysics is to directly observe the immediate environment of a black hole with angular resolution comparable to the event horizon. Realizing this goal would open a new...
The Murchison Widefield Array: Design Overview (2009)
Lonsdale, Colin J., Cappallo, Roger J., Morales, Miguel F., Briggs, Frank H., Benkevitch, Leonid, Bowman, Judd D., ...
The Murchison Widefield Array (MWA) is a dipole-based aperture array synthesis telescope designed to operate in the 80-300 MHz frequency range. It is capable of a wide range of science...
Observing Neutral Hydrogen Above Redshift 6: The "Global" Perspective (2009)
Bowman, Judd D., Rogers, Alan E. E., Hewitt, Jacqueline N.
Above redshift 6, the dominant source of neutral hydrogen in the Universe shifts from localized clumps in and around galaxies and filaments to a pervasive, diffuse component of the intergalactic...
Methods for detecting flaring structures in Sagittarius A* with high frequency VLBI (2008)
Doeleman, Sheperd S., Fish, Vincent L., Broderick, Avery E., Loeb, Abraham, Rogers, Alan E. E.
The super massive black hole candidate, Sagittarius A*, exhibits variability from radio to X-ray wavelengths on time scales that correspond to < 10 Schwarzschild radii. We survey the potential of...
Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre (2008)
Doeleman, Sheperd, Weintroub, Jonathan, Rogers, Alan E. E., Plambeck, Richard, Freund, Robert, Tilanus, Remo P. J., ...
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 (ref 1). Sagittarius...
Observing Neutral Hydrogen Above Redshift 6: The “Global” Perspective (2008)
Bowman, Judd D., Rogers, Alan E. E., Hewitt, Jacqueline N.
Above redshift 6, the dominant source of neutral hydrogen in the Universe shifts from localized clumps in and around galaxies and filaments to a pervasive, diffuse component of the intergalactic...
Spectral index of the diffuse radio background measured from 100 to 200 MHz (2008)
Rogers, Alan E. E., Bowman, Judd D.
The mean absolute brightness temperature of the diffuse radio background was measured as a function of frequency in a continuous band between 100 and 200 MHz over an effective solid angle of ~π sr...
Detecting Flaring Structures in Sagittarius A* with (Sub)Millimeter VLBI (2008)
Fish, Vincent L., Doeleman, Sheperd S., Broderick, Avery E., Loeb, Abraham, Rogers, Alan E. E.
Multiwavelength monitoring observations of Sagittarius A* exhibit variability on timescales of minutes to hours, indicating emission regions localized near the event horizon....
Spectral Index of the Diffuse Radio Background Measured From 100 to 200 MHz (2008)
Rogers, Alan E. E., Bowman, Judd D.
The mean absolute brightness temperature of the diffuse radio background was measured as a function of frequency in a continuous band between 100 and 200 MHz over an effective solid angle of ~pi str...
Bowman, Judd D., Rogers, Alan E. E., Hewitt, Jacqueline N.
Preliminary results are presented from a simple, single-antenna experiment designed to measure the all-sky radio spectrum between 100 and 200 MHz. The system used an internal comparison-switching...
A RADAR INTERFEROMETER STUDY OF VENUS AT 3.8 CM. (2005)
Rogers,Alan E. E., Hagfors,Tor, Brockelman,Richard A., Ingalls,Richard P., Levine,James I.
The 120-foot antenna of the Haystack Microwave Facility and the 60-foot antenna of the Westford Communications Terminal, both operated by M.I.T. Lincoln Laboratory, were coupled to form a planetary...
VERY LONG BASELINE INTERFEROMETRY AS A MEANS OF WORLDWIDE TIME SYNCHRONIZATION. (2005)
Extraterrestrial radio waves from sources of small angular size can be used to synchronize clocks at two receiving sites to a high degree of precision. Radio star signals, together with time...
Global 3- and 7-mm VLBI Observations of OJ287 (1996)
Tateyama, Claudio E., Inuoe, Makoto, Krichbaum, Thomas P., Bååth, Lars B., Kameno, Seji, Rogers, Alan E.E., ...
We present new results from global VLBI observations of the highly active blazar OJ287 at 7 and 3 mm wavelengths. We show the first map of the mas to sub-mas structure of OJ287 at 43 GHz and discuss...