| NSF Org: |
AST Division Of Astronomical Sciences |
| Recipient: |
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| Initial Amendment Date: | December 21, 2017 |
| Latest Amendment Date: | December 21, 2017 |
| Award Number: | 1716965 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Hans Krimm
hkrimm@nsf.gov (703)292-2761 AST Division Of Astronomical Sciences MPS Directorate for Mathematical and Physical Sciences |
| Start Date: | January 15, 2018 |
| End Date: | December 31, 2020 (Estimated) |
| Total Intended Award Amount: | $232,085.00 |
| Total Awarded Amount to Date: | $232,085.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
10889 WILSHIRE BLVD STE 700 LOS ANGELES CA US 90024-4200 (310)794-0102 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
Los Angeles CA US 94704-5940 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | STELLAR ASTRONOMY & ASTROPHYSC |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.049 |
ABSTRACT
Telescopes designed for observing signals made by the Cosmic Microwave Background also provide a unique opportunity for long-term monitoring of large areas of the sky for variable astronomical sources at millimeter-sized wavelengths. This is a spectral region of observational astronomy now largely unexplored. The investigators will use the South Pole Telescope to conduct the first systematic survey of the sky in the millimeter band. This survey could reach sensitivities that would allow the first detections of Gamma Ray Bursts made by the first generation of stars during very early stages of the development of the universe. It will also produce a wealth of detailed data on variability within active galaxies with time, and has the capability of detecting very fast radio bursts. These data will generate many opportunities for university undergraduate students to work with a large, novel, and ready-to-analyze data set.
This program uses the South Pole Telescope to conduct a real-time survey of 2500 square degrees of sky in the 90-220 GHz band for transient and variable sources, targeting in particular gamma ray burst afterglows, active galaxies, and fast radio bursts. Using the 3rd-generation receiver (to be deployed in the 2016-2017 austral summer), this survey will cover 6% of the sky hourly over a period of two years. This has the sensitivity potential to make the first detections of gamma-ray burst afterglows unassociated with a gamma-ray trigger. This program will improve on the existing best sensitivity in this spectral range by a factor of 50, address a number of open questions in high-energy astrophysics, and firmly establish Cosmic Microwave Background telescopes as tools for time-domain astronomy.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
This project was designed to perform the first survey for transient astrophysical sources (e.g. supernovae, gamma-ray bursts) in the millimeter band, opening a new window on the sky. Such observations could potentially result in the discovery of new classes of object or provide fundamentally new information about already-known, but not completely understood, extreme objects like gamma-ray bursts.
Data were taken using the third generation receiver on the South Pole Telescope, located at Amundsen-Scott South Pole Station, beginning with data from 2019. This award supported the successful design and deployment of the first real-time, on-site analysis system for a CMB telescope, resulting in the production of science-quality millimeter-band maps and an automated search for transient point sources completed within 12 hours of data-taking by SPT-3G. The alert system was enabled in October 2020 and has been operational since then, outside of summer telescope maintenance and the use of the telescope for the Event Horizon Telescope project. In addition, we completed an offline analysis of 2020 data from SPT-3G. Sources discovered by the online and offline searches enabled by this grant have revealed fifteen transient sources of a variety of types in this band, from none previously detected in blind surveys before this award.
The majoriy of these detected sources are stellar flares, of a type rarely seen before, and which are now known, as a result of this award, to be both bright and common and will contribute to our understanding of stellar astrophysics. In addition, two extragalactic sources of an unknown type, associated with distant galaxies, were detected. It is not yet clear if these are extreme examples of known source classes (for example, flares from gas or stars falling into the supermassive black holes in active galaxies) or something entirely new. Results from this program are now informing the design of future instruments to answer these questions.
This proposal also supported an outreach program, including presentations at a number of science-festival events (UCLA's "Exploring Your Universe" in 2018, 2019, and 2020, Astro on Tap in 2019, presentations at Los Angeles-area Title I schools in 2019, and Skype a Scientist virtual presentations to schools in a number of states in 2020).
Last Modified: 04/30/2021
Modified by: Nathan Whitehorn
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