Dr Werthimer and his collaborators will conduct a survey with the Arecibo radio telescope to search for narrow band and pulsed signals varying over milliseconds to microseconds. They will use the 7-beam Arecibo L-band Feed Array (ALFA); SERENDIP V, a new spectrometer that the team developed under a past NSF award; and SETI@home II, their real-time multi-beam data recorder. Their spectrometer will take data continuously while the Arecibo telescope is being used for other surveys. This will be analyzed by volunteers who provide unused cycles on home computers, on the model of SETI@home. The new survey will be 14 times more sensitive than the best previous work. In addition to artificial narrow-band signals, the survey will search for pulsars with high dispersion measures and short periods or short duty cycles; pulses associated with evaporating primordial black holes; and potentially, giant pulses from undiscovered pulsars.
This project will involve the public as active participants. Data sets, project news and educational materials will be distributed via the SETI@home website. Graduate and undergraduate students will help to design the survey and participate in the research. The team's new methods for commensal (parallel) observations, for reduction and analysis of multibeam data, and for removal of radio interference signals, will be useful at other observatories.
This research uses the world's largest radio telescope, the Arecibo telescope in Puerto Rico, to search for short time scale radio pulses that could come from extraterrestrial civilizations or new astrophysical phenomena. Analyzing telescope data for pulses as short as one millionth of a second requires an enormous amount of computer time, so we have asked volunteers to help us; hundreds of thousands of SETI@home and Astropulse volunteers are participating in this global science project by using their computers at home, offices and schools to analyze the data. SETI@home and Astropulse volunteers haved formed one of Earth's most powerful supercomputers, and enabled a highly sensitive and powerful search for a rich variety of signals. Our sky survey uses Arecibo multi-beam receiver. We have collected and analyzed 300 terabytes of data so far, and are continuing to observe at Arecibo during all astronomical survey work. We have covered almost the entire sky visible from the Arecibo telescope. Astropulse is a new type of SETI. It expands on the original SETI@home project, but does not replace it. The original SETI@home search is narrowband, meaning that it is listening for a particular radio frequency. That's like listening to an orchestra playing, and trying to hear when anyone plays the note "A sharp". Astropulse searches for short-time pulses. In the orchestra analogy, it's like listening for a drum beat, or a series of drumbeats. Since no one knows what extraterrestrial communications will "sound like," it's good to search for several types of signals. In scientific terms, Astropulse is a sky survey that searches for dispersed microsecond transient radio pulses. These pulses could come from another civilization, or from a natural source, such as a pulsar, a rotating radio transient (RRAT), an evaporating primordial black hole, or new astrophysical phenomenon. We have identified roughly 100 candidate radio pulses; many candidates are in the plane of the milkyway galaxy. None of these candidates are signals from another civilization. The candidate signals might be radio interference, or they might be radio pulses from astrophysical phenomena. We recently conducted re-observations of these candidate sky locations at Arecibo and are currently examining this data to try to understand the nature of the candidate radio pulses. SETI@home and Astropulse are open source projects, as is the BOINC distributed computing infrastructure developed for SETI@home. Over 100 volunteer scientific supercomputing projects utilize BOINC.
