BEIJING, China--(BUSINESS WIRE)--The preliminary round of the 2020-2021 ASC Student Supercomputer Challenge (ASC20-21) has kicked off. In two months, participating teams from universities around the world will participate in a cutting-edge challenge - searching for pulsars. Teams will use the open-source software, PRESTO, to search for pulsar signals with the goal to minimize time and resources utilized. Real observational data gathered by “China Sky Eye”, the Five-hundred-meter Aperture Spherical radio Telescope (FAST), will be used as input for PRESTO. This task is designed for university students to directly assist FAST in searching for pulsars while igniting their passion to explore the mystery of universe.
Ever wonder how is pulsar searching related to FAST and supercomputing? What is the most challenging part of this task? Dr. Jiarui Niu from the National Astronomical Observatories, Chinese Academy of Sciences (CAS) provided the answers to these questions during the ASC20-21 online training camp of November 30, 2020.
Pulsars: Cosmic Clocks
The theoretical study of pulsars is a cutting-edge research topic in modern astrophysics because their unique physical properties make them a cosmic laboratory for physics research under extreme conditions. Two Nobel Prizes in physics has been awarded for pulsar-related discoveries. Major breakthroughs such as the discovery of gravitational waves, and the confirmation of black holes, are directly and indirectly related to advances in pulsar theories. Since pulsar’s radio emission periods are remarkably stable and comparable to atomic clocks, by observing the pulsar signals scientists can unravel major conundrums related to the physics of compact stars, attest gravitational wave theories, and discover new properties of the universe. A promising application for spacecraft navigation technique is using the highly accurate pulsar timing to develop a cosmic "GPS" or “Pulsar Navigation”, which helps spacecraft traverse the vast expanses of the universe.
Pulsar Searching and Supercomputing
Currently, more than 3000 pulsars have been discovered, but this is only a fraction of the estimated total number in the universe. Pulsars are very distant and compact, so their observation needs enormously powerful radio telescopes to detect their radiation burst. FAST, the world's largest and most sensitive single-dish radio telescope, is mainly dedicated to searching for pulsars. Based on observational data provided by FAST, astronomers have already discovered more than 240 new pulsars.
There are two main reasons why searching for pulsars is difficult. First, there is a significant amount of RF interference from Earth’s surrounding environment, which is far stronger than the pulsar signals. Identifying and eliminating these interferences presents major difficulties in searching for pulsars. Second, there is a vast amount of observational data. FAST pulsar observation generates 6GB of data per second or several petabytes per month. To store and analyze this huge amount of data, scientists need to use powerful supercomputers, specialized software, and implement optimized algorithms to output results in a timely manner.
PRESTO, an open-source pulsar search software used by scientist, has become an essential tool to efficiently search for millisecond pulsars, based on observations of faraway globular clusters. Out of more than 3000 pulsars discovered by all the radio telescopes in recent decades, more than 700 were discovered with the help of PRESTO software.
The first step in searching for pulsars with PRESTO is to filter- eliminate as many RF interfering signals as possible from the surrounding environment. Next, the signals need to be de-dispersed in time series. Then, a Fast Fourier Transform must be performed on the time series to find the periodic signals, apply folding, and finally generate a graph of a possible pulsar candidate.
Since scientists cannot calculate in advance the exact distance, spin, and trajectory of pulsars, the search for pulsars is essentially a "blind search" in the dataset. It requires developing a wide range of search parameters to maximize the detection rate in the massive search result volume and filter for candidate images.
ASC Inspires University Students to Explore the Universe
The PRESTO task requires each participating team to search through the FAST observational dataset provided by the organizing committee. The goal is to discover pulsar candidates by analyzing and optimizing PRESTO software execution. Teams will minimize computation time, computer hardware resources, and make sure that the power consumption should always remain under 3KW.
Dr. Niu noted that the task will challenge the participating teams in both theory and in practice. In theory, it presents an excellent opportunity for the students to learn about the astrophysics of pulsars and sparks their ingenuity and innovation for exploring the mysteries of the universe. In practice, the FAST data and the PRESTO task software are directly used in the contemporary pulsar search, which exposes undergraduates to real scientific data and software used by world renowned scientists.
The ASC Student Supercomputer Challenge is the world’s largest student supercomputer competition, sponsored and organized by Asia Supercomputer Community and supported by Asian, European, and American experts and institutions. The main objectives of ASC are to encourage exchange and training of young supercomputing talent from different countries, improve supercomputing applications and R&D capacity, boost the development of supercomputing, and promote technical and industrial innovation. The first ASC Student Supercomputer Challenge was held in 2012 and since has attracted nearly 10,000 undergraduates from all over the world. Learn more ASC at https://www.asc-events.org/.