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Full-Text Articles in Physics
Time-Resolved Au-Scale Jets Traced By Masers In The Iras 4a/B Regions Of Ngc 1333, Bruce Wilking, Kevin Marvel, Mark Claussen, Alwyn Wootten
Time-Resolved Au-Scale Jets Traced By Masers In The Iras 4a/B Regions Of Ngc 1333, Bruce Wilking, Kevin Marvel, Mark Claussen, Alwyn Wootten
Physics Faculty Works
We present results of VLBI observations of the water masers associated with IRAS 4A and IRAS 4B in the NGC 1333 star-forming region taken in four epochs over a two month period. Both objects have been classified as extremely young sources, and each source is known to be a multiple system. Using the Very Long Baseline Array, we detected 35 masers in epoch I, 40 masers in epoch II, 35 in epoch III, and 24 in epoch IV. Only one identified source in each system is associated with these masers. These data are used to calculate proper motions for the …
The Occurrence Of Ionospheric Signatures Of Plasmaspheric Plumes Over Different Longitudinal Sectors, E. Yizengaw, J. Dewar, J. Macneil, D. Galvan, Jeff Sanny, David Berube, B. Sandel
The Occurrence Of Ionospheric Signatures Of Plasmaspheric Plumes Over Different Longitudinal Sectors, E. Yizengaw, J. Dewar, J. Macneil, D. Galvan, Jeff Sanny, David Berube, B. Sandel
Physics Faculty Works
Plasmaspheric plumes have ionospheric signatures and are observed as storm-enhanced density (SED) in global positioning system (GPS) total electron content (TEC). These ionospheric signatures have been primarily observed over the American sector and in a few limited examples over the European sector. This study examines the longitudinal occurrence frequency of plasmaspheric plumes. We analyzed all images from the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) Extreme Ultraviolet Imager (EUV) databases for the first half of 2001 and identified a total of 31 distinct plume intervals observed during different storm events. Out of the total IMAGE EUV plumes that we identified, 12 …
The Peculiar Volatile Composition Of Comet 8p/Tuttle: A Contact Binary Of Chemically Distinct Cometesimals?, Boncho Bonev, Michael Mumma, Yana Radeva, Michael Disanti, Erika Gibb, Geronimo Villanueva
The Peculiar Volatile Composition Of Comet 8p/Tuttle: A Contact Binary Of Chemically Distinct Cometesimals?, Boncho Bonev, Michael Mumma, Yana Radeva, Michael Disanti, Erika Gibb, Geronimo Villanueva
Physics Faculty Works
We report measurements of eight native (i.e., released directly from the comet nucleus) volatiles (H2O, HCN, CH4, C2H2, C2H6, CO, H2CO, and CH3OH) in comet 8P/Tuttle using NIRSPEC at Keck 2. Comet Tuttle reveals a truly unusual composition, distinct from that of any comet observed to date at infrared wavelengths. The prominent enrichment of methanol relative to water contrasts with the depletions of other molecules, especially C2H2, HCN, and H2CO. We suggest that the nucleus of 8P/Tuttle may contain two cometesimals characterized by distinct volatile composition. The relative abundances C2/CN, C2/OH, and CN/OH in 8P/Tuttle (measured at optical/near-UV wavelengths) differ …
Unparticle-Enhanced Black Holes At The Lhc, Jonas R. Mureika
Unparticle-Enhanced Black Holes At The Lhc, Jonas R. Mureika
Physics Faculty Works
Based on the idea that tensor unparticles can enhance the gravitational interactions between standard model particles, potential black hole formation in high energy collisions is examined. Modifications to the horizon radius rH are derived, and the corresponding geometric cross-sections of such objects are calculated. It is shown that rH increases dramatically to the electroweak scale for masses MBH∼1–10 TeV, yielding a geometric cross-section σBH=πr2H on the order of ⩽50 pb. This suggests that unparticle physics provides a mechanism for black hole formation in future accelerators, without the requirement of extra spatial dimensions.
Eight Minutes And A Half, Gabriele U. Varieschi
Eight Minutes And A Half, Gabriele U. Varieschi
Physics Faculty Works
No abstract provided.
Thermal Roots Of Correlation-Based Complexity, Philip Fraundorf
Thermal Roots Of Correlation-Based Complexity, Philip Fraundorf
Physics Faculty Works
Bayesian maxent lets one integrate thermal physics and information theory points of view in the quantitative study of complex systems. Since net surprisal (a free energy analog for measuring “departures from expected”) allows one to place second law constraints on mutual information (a multimoment measure of correlations), it makes a quantitative case for the role of reversible thermalization in the natural history of invention, and suggests multiscale strategies to monitor standing crop as well. It prompts one to track evolved complexity starting from live astrophysically observed processes, rather than only from evidence of past events. Various gradients and boundaries that …
The Biot-Savart Law: From Infinitesimal To Infinite, Jeffrey A. Phillips, Jeff Sanny
The Biot-Savart Law: From Infinitesimal To Infinite, Jeffrey A. Phillips, Jeff Sanny
Physics Faculty Works
In this paper, we discuss a simple apparatus and accompanying class activity that we have developed to illustrate the Biot-Savart law. Since students in introductory electricity and magnetism courses often find this law a mathematical mystery, we feel that a simple experiment such as this will provide the students a better understanding of the concepts introduced. By collecting data from several finite segment lengths, students are able to infer the 1/r2 distance dependence of the magnetic field for infinitesimal segments and the 1/r dependence for infinite wires.