Lazio, T. Joseph W., Carmichael, S., Clark, J., Elkins, E., Gudmundsen, P., Mott, Z., ...
This paper reports a blind search for magnetospheric emissions from planets around nearby stars. Young stars are likely to have much stronger stellar winds than the Sun, and because planetary...
Lazio, T. Joseph W., Brogan, C. L., Goss, W. M., Stanimirovic, S.
This paper reports dual-epoch, Very Long Baseline Array observations of H I absorption toward 3C 147. One of these epochs (2005) represents new observations while one (1998) represents the...
GCRT J1742-3001: A New Radio Transient Towards the Galactic Center (2008)
Hyman, Scott D., Wijnands, Rudy, Lazio, T. Joseph W., Pal, Sabyasachi, Starling, Rhaana, Kassim, Namir E., ...
We report the detection of a new transient radio source, GCRT J1742-3001, located ~1 degree from the Galactic center. The source was detected ten times from late 2006 to 2007 May in our 235 MHz...
Further Constraints on the Presence of a Debris Disk in the Multiplanet System Gliese 876 (2008)
Shankland, Paul D., Blank, David L., Boboltz, David A., Lazio, T. Joseph W., White, Graeme
Using both the Very Large Array (VLA) at 7mm wavelength, and the Australia Telescope Compact Array (ATCA) at 3mm, we have searched for microwave emission from from cool dust in the extrasolar...
Magnetospheric Emissions from the Planet Orbiting tau Boo: A Multi-Epoch Search (2007)
Lazio, T. Joseph W., Farrell, W. M.
All of the solar system gas giants produce electron cyclotron masers, driven by the solar wind impinging on their magnetospheres. Extrapolating to the planet orbiting tau Boo, various authors have...
A Faint, Steep Spectum Burst from the Radio Transient GCRT J1745-3009 (2007)
Hyman, Scott D., Roy, Subhashis, Pal, Sabyasachi, Lazio, T. Joseph W., Ray, Paul S., Kassim, Namir E., ...
GCRT J1745-3009 is a transient bursting radio source located in the direction of the Galactic center. It was discovered in a 330 MHz VLA observation from 2002 September 30--October 1 and subsequently...
74 MHz Discrete HII Absorption Regions Towards The Inner Galaxy (2006)
Nord, Michael E., Henning, P. A., Rand, R. J., Lazio, T. Joseph W., Kassim, Namir E.
At low radio frequencies (< 100 MHz), classical HII regions may become optically thick (optical depth > 1) and can be observed as discrete absorption regions against the Galactic nonthermal...
A New Radio Detection of the Bursting Source GCRT J1745-3009 (2005)
Hyman, Scott D., Lazio, T. Joseph W., Roy, Subhashis, Ray, Paul S., Kassim, Namir E.
GCRT J1745-3009 is a transient bursting radio source located in the direction of the Galactic center, discovered in 330 MHz VLA observations from 2002 September 30--October 1 by Hyman et al. We have...
The Exploration of the Unknown (2004)
Wilkinson, P. N., Kellermann, K. I., Ekers, R. D., Cordes, J. M., Lazio, T. Joseph W.
The Square Kilometre Array is conceived as a telescope which will both test fundamental physical laws and transform our current picture of the Universe. However, the scientific challenges outlined in...
The Microarcsecond Sky and Cosmic Turbulence (2004)
Lazio, T. Joseph W., Cordes, J. M., De Bruyn, A. G.
Radio waves are imprinted with propagation effects from ionized media through which they pass. Owing to electron density fluctuations, compact sources (pulsars, masers, and compact extragalactic...
Cordes, James M., Lazio, T. Joseph W., McLaughlin, M. A.
Transient radio sources are necessarily compact and usually are the locations of explosive or dynamic events, therefore offering unique opportunities for probing fundamental physics and astrophysics....
High-Resolution, Wide-Field Imaging of the Galactic Center Region at 330 MHz (2004)
Nord, Michael E., Lazio, T. Joseph W., Kassim, Namir E., Hyman, S. D., LaRosa, T. N., Brogan, C., ...
We present a wide field, sub-arcminute resolution VLA image of the Galactic Center region at 330 MHz. With a resolution of ~ 7" X 12" and an RMS noise of 1.6 mJy/beam, this image represents a...
Gelfand, Joseph D., Lazio, T. Joseph W., Gaensler, B. M.
We present here the results of a 325 MHz radio survey of M31, conducted with the A-configuration of the Very Large Array. The survey covered an area of 7.6 deg$^2$, and a total of 405 radio sources...
LaRosa, T. N., Nord, Michael E., Lazio, T. Joseph W., Kassim, Namir E.
New high-resolution, wide-field 90 cm VLA observations of the Galactic Center region by Nord et al. have revealed twenty nonthermal filament (NTF) candidates. We report 6 cm polarization observations...
Detection of Sagittarius A* at 330 MHz with the Very Large Array (2003)
Nord, Michael E., Lazio, T. Joseph W., Kassim, Namir E., Goss, W. M., Duric, N.
We report the detection of Sagittarius A*, the radio source associated with our Galaxy's central massive black hole, at 330 MHz with the Very Large Array. Implications for the spectrum and emission...
Lazio, T. Joseph W., Tarter, Jill, Backus, Peter R.
This paper reports new, more sensitive observations of nine of the eleven extrastatistical signals in the Megachannel Extraterrestrial Assay (META). These extrastatistical signals had all of the...
Low-Frequency Radio Transients in the Galactic Center (2001)
Hyman, Scott D., Lazio, T. Joseph W., Kassim, Namir E.
We report the detection of a new radio transient source, GCRT J1746-2757, located only 1.1 degrees north of the Galactic center. Consistent with other radio transients toward the Galactic center,...
LaRosa, T. N., Lazio, T. Joseph W., Kassim, Namir E.
We report the discovery of a system of isolated nonthermal filaments approximately 0.5 deg. northwest (75 pc in projection) of Sgr A. Unlike other isolated nonthermal filaments which show...
Lazio, T. Joseph W., Fey, A. L.
We present multi-frequency observations with the Very Long Baseline Array of the compact double radio source B2 2050+36. Our observations are at 0.33, 0.61, 1.67, 2.3, and 8.4 GHz, with the 0.61 GHz...
Spatially-resolved Thermal Continuum Absorption against the Supernova Remnant W49B (2001)
Lacey, C. K., Lazio, T. Joseph W., Kassim, Namir E., Duric, N., Briggs, D. S., Dyer, K. K.
We present sub-arcminute resolution imaging of the Galactic supernova remnant W49B at 74 MHz (25") and 327 MHz (6"), the former being the lowest frequency at which the source has been resolved. While...
A Dual Frequency, Multi-Year Monitoring Program of Compact Radio Sources (2001)
Lazio, T. Joseph W., Waltman, E. B., Ghigo, F. D., Fiedler, R. L., Foster, R. S., Johnston, K. J.
We present light curves for 149 sources monitored with the Green Bank Interferometer. The light curves are at two radio frequencies (approximately 2.5 and 8.2 GHz) and range from 3 to 15 yrs in...
Extreme Scattering Events: An Observational Summary (2000)
Lazio, T. Joseph W., Fey, Alan L., Gaume, R. A.
We review observational constraints on the structures responsible for extreme scattering events, focussing on a series of observations of the quasar PKS 1741-038. VLA observations were conducted to...
Anomalous Radio-Wave Scattering from Interstellar Plasma Structures (2000)
Cordes, J. M., Lazio, T. Joseph W.
This paper considers scattering screens that have arbitrary spatial variations of scattering strength transverse to the line of sight, including screens that are spatially well confined, such as...
Upper Limits on the Continuum Emission from Geminga at 74 and 326 MHz (1999)
Kassim, Namir E., Lazio, T. Joseph W.
We report a search for radio continuum emission from the gamma-ray pulsar Geminga. We have used the VLA to image the location of the optical counterpart of Geminga at 74 and 326 MHz. We detect no...
The Extreme Scattering Event Toward PKS 1741-038: VLBI Images (1999)
Lazio, T. Joseph W., Fey, A. L., Dennison, Brian
(Abridged) We report multi-epoch VLBI observations of the source PKS 1741-038 as it underwent an extreme scattering event. Observations at four epochs were obtained, and images were produced at three...
Lazio, T. Joseph W., Anantharamaiah, K. R., Goss, W. M., Kassim, Namir E., Cordes, James M.
G359.87+0.18 is an enigmatic object located 15' from Sgr A*. It has been variously classified as an extragalactic source, Galactic jet source, and young supernova remnant. We present new observations...
Lazio, T. Joseph W., Cordes, James M.
The scattering diameters of Sgr A* and several nearby OH masers (~ 1" at 1 GHz) indicate that a region of enhanced scattering is along the line of sight to the Galactic center. The scattering...
Lazio, T. Joseph W., Cordes, James M.
The scattering diameters of Sgr A* and several nearby OH masers (~ 1" at 1 GHz) indicate that a region of enhanced scattering is along the line of sight to the Galactic center. We combine radio-wave...
Lazio, T. Joseph W., Cordes, James M.
We use radio-wave scattering data to constrain the distribution of ionized gas in the outer Galaxy. Like previous models, our model for the H II disk includes parameters for the radial scale length...
Lazio, T. Joseph W., Cordes, James M.
We report multifrequency Very Long Baseline Array observations of twelve active galactic nuclei seen toward the Galactic anticenter. All of the sources are at |b| < 10 degrees and seven have |b| <...
The Gaussian Plasma Lens in Astrophysics. Refraction (1997)
Clegg, Andrew W., Fey, Alan L., Lazio, T. Joseph W.
We consider the geometrical optics for refraction of a distant radio source by an interstellar plasma lens, with application to a lens with a Gaussian electron column density profile. The refractive...
Scintillation-Induced Intermittency in SETI (1997)
Cordes, James M., Lazio, T. Joseph W., Sagan, Carl
We consider interstellar scintillations as a cause of intermittency in radio signals from extraterrestrial intelligence (ETI). We demonstrate that scintillations are very likely to allow initial...
Thesis (Ph. D.)--Cornell University, 1997.
Genetic algorithms, pulsar planets, and ionized interstellar microturbulence / (1997)
Lazio, T. Joseph W. (Thomas Joseph Wuggazer)
Thesis (Ph. D.)--Cornell University, May, 1997.
Finding Radio Pulsars in and Beyond the Galactic Center (1996)
Cordes, James M., Lazio, T. Joseph W.
Radio-wave scattering is enhanced dramatically for Galactic center sources in a region with radius >~ 15 arc min. Using scattering from Sgr A* and other sources, we show that pulse broadening for...
Images of HCO+ (1-0) Emission in a Molecular Cloud near 1E1740.7-2942 (1994)
Phillips, J. A., Lazio, T. Joseph W.
We have observed the hard X-ray source 1E1740.7-2942 in the HCO+ (1-0) line using the Owens Valley millimeter interferometer. Previous single dish observations have found HCO+ emission coincident...