Papers by Gerald Harp
X-Ray Secondary-Emission Microscopy (XSEM) of Neurons
Europhysics Letters (EPL), 1992
We present the first X-ray secondary (photoelectron) emission microscopy (XSEM) pictures and vide... more We present the first X-ray secondary (photoelectron) emission microscopy (XSEM) pictures and video microimages of an uncoated and unstained neuron specimen. This novel kind of synchrotron radiation microscopy is suitable for local chemical analysis with a lateral resolution in the micron range. We explored the details of the neuron system, demonstrated chemical contrast by scanning the photon energy, studied in real time the photoelectron emitting properties of the specimen's components, and made preliminary tests of the radiation damage. These results significantly enhance the potential role of photoemission techniques in the life sciences and specifically in neurobiology.
The Allen Telescope Array (ATA) is a Large-Number-Small-Diameter radio telescope array currently ... more The Allen Telescope Array (ATA) is a Large-Number-Small-Diameter radio telescope array currently with 42 individual antennas and 5 independent back-end science systems (2 imaging FX correlators and 3 time domain beam formers) located at the Hat Creek Radio Observatory (HCRO). The goal of the ATA is to run multiple back-ends simultaneously, supporting multiple science projects commensally. The primary software control systems are based on a combination of Java, JRuby and Ruby on Rails. The primary control API is simplified to provide easy integration with new back-end systems while the lower layers of the software stack are handled by a master observing system. Scheduling observations for the ATA is based on finding a union between the science needs of multiple projects and automatically determining an efficient path to operating the various sub-components to meet those needs. When completed, the ATA is expected to be a world-class radio telescope, combining dedicated SETI projects with numerous radio astronomy science projects.
The Search for ExtraTerrestrial Intelligence (SETI) finally has its own full-time telescope. The ... more The Search for ExtraTerrestrial Intelligence (SETI) finally has its own full-time telescope. The Allen telescope array (ATA) in Northern California was dedicated on October 11, 2007. This array, which will eventually be composed of 350 small radio antennas, each 6.1 m in diameter, is being built as a partnership between the SETI Institute and the University of California Radio Astronomy Laboratory. Last October, Paul G. Allen (who provided the funds for the technology development and the first phase of array construction) pushed a silver button and all 42 antennas of the current ATA-42 slewed to point in the direction of the distant galaxy M81. Specialized electronic backend detectors attached to the ATA began making a radio map of that galaxy and simultaneously began SETI observations of HIP48573, a G5V star near M81 on the sky and a distance of 264 light years from Earth. The Allen telescope array will greatly improve the speed of conducting SETI searches over the next few decades, and it will allow a suite of different search strategies to be undertaken. This paper summarizes some of the earliest SETI observations from the array, and describes the search strategies currently being planned.
PiHi Observations at the ATA, Conventional and Unconventional SETI
Many radio SETI searches focus on the frequency range where the HI (1.42 GHz) and OH lines (1.6-1... more Many radio SETI searches focus on the frequency range where the HI (1.42 GHz) and OH lines (1.6-1.7 GHz) lines are landmarks delineating the water hole This is only a small fraction of the terrestrial microwave window (TMW) from 1-10 GHz. This survey occurs near the center of the TMW at 4.462336275 GHz or pi times the HI frequency. We
SETI and astrobiology papers with NO full text by Gerald Harp
Getting the World Actively Involved in SETI Searches
Getting the World Actively Involved in SETI Searches Jill C. Tarter, Avinash Agrawal, Rob Ackerma... more Getting the World Actively Involved in SETI Searches Jill C. Tarter, Avinash Agrawal, Rob Ackermann, Samantha K. Blair, M. Tucker Bradford, Danese M ... M. Dexter, G. Engargiola, E. Fields, J. Forster, C. Gutierrez-Kraybill, C. Heiles, T. Helfer, S. Jorgensen, G. Keating, J. Lugten, D ...
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Papers by Gerald Harp
SETI and astrobiology papers with NO full text by Gerald Harp